"If you think it's expensive to hire a professional to do the job, wait until you hire an amateur." Red Adair
Offering Specialized Consumer Protection Professional EIFS/Stucco/Siding and Moisture Inspection Services in the D/FW market, all of Texas and wherever else you need me...for the Right Price!
Call Barry at 214-328-8331 to Schedule your Specialist Inspection appointment
In accordance with the standards set forth by all EIFS manufactures and the organizations below. I have installed and inspected hundreds of start up and completed residential and commercial projects in Texas and Louisiana. Although I no longer partake in the actual installation of EIFS/Stucco/Siding I am available for construction consultations, installation over site, phase inspections, and the inspection of new, remediation, and finished or older properties that are clad with EIFS, stucco, siding or any other type of exterior veneer that requires conclusive factual information.
Properly specified and detailed, EIFS can provide a lightweight and versatile cladding system for many applications.
By: John Straube
EIFS (pronounced "eefs")--an acronym for Exterior Insulated Finish System--can be defined as a lightweight exterior cladding system consisting of insulation board (expanded polystyrene or occasionally mineral wool) adhered or mechanically fastened to a wind-load-bearing substrate, and covered with an integrally reinforced base coat and a protective surface finish. The EIFS industry is rife with special terminology--some of the most important terms are shown in the figure below.
There are several reasons for the continued growth of the EIFS market: the systems are lightweight and hence impose few structural restrictions on their use; the polymer-based finishes allow for a vast range of colours and textures; the foam plastic insulation used by most systems can be easily shaped to form cornices, reveals, trim, etc.; and the insulation improves energy efficiency by wrapping the whole building in an uninterrupted blanket.
In the past, two broad categories of EIFS were defined based primarily on the type of lamina used: soft-coat/polymer-based (PB) systems and hard-coat/polymer-modified (PM) systems. The former system tended to use thinner lamina, adhesive attachment and expanded polystyrene insulation, while the latter used thicker, harder lamina, often with glass fibre mesh reinforcement, on mechanically fastened extruded polystyrene insulation. The many combinations of systems now available limit the value of such classifications.
The location and manner of construction are also important considerations. Prefabricated or site-fabricated panels, usually with steel backup, are often designed and built in a different manner than field-applied EIFS. An EIF system with a high polymer-content thin (2-3 mm) base coat reinforced with polymer-coated glass mesh, an all-polymer finish coat, expanded polystyrene insulation and adhesive fastening is currently one of the most popular.
The roots of EIFS can be traced to Swedish systems from the 1940s that applied steel mesh reinforced cement-lime stuccoes over high-density rockwool board insulation. The relatively flexible insulation and the mesh reinforcement minimized cracking and wrapped the entire opaque wall in a continuous insulation blanket.
The commercial and technical development of modern EIFS occurred primarily in Germany after World War II. War-related shortages led to the development of synthetic polymers as alternatives to petroleum and natural rubber. Edwin Horbach, a Swiss-trained chemist, is generally credited with implementing the use of polymer-based stucco reinforced with alkali-protected glass fibre mesh over expanded polystyrene insulation. The ability of such a lightweight system to be quickly and easily applied to war-damaged and uninsulated masonry buildings perfectly suited labour- and resource-starved post-war Europe.
EIFS did not become widely available in North America until the oil crisis of the early 1970s. The success of the so-called polymer-based or thin coat EIFS drove the development of a wide range of systems employing a variety of finishes, insulation materials, and reinforcing types. Unlike the moisture-tolerant masonry substrates of Europe, EIFS in North America has been mostly applied over moisture-sensitive substrates of wood and gypsum. Hence, even a small leak could cause serious damage.
As EIFS began to be used more commonly, certain moisture problems were reported, especially in the 1990s. Thousands of Wilmington, North Carolina single-family homes clad with EIFS exhibited serious and well-publicized moisture-related problems. Despite the many confounding variables involved in the problems with these homes, EIFS were often blamed. In most cases problems with EIFS have related to rain penetration, limited drying and inappropriate vapour barriers. These problems occurred because old designs relied on a single barrier exposed to the weather to resist rain penetration. In many cases water infiltrated at face-sealed joints and through-wall penetrations such as windows, decks, and air conditioning units.
Rot and decay of moisture-sensitive substrates has been, and remains, the largest concern with EIFS. However, this can be minimized by the use of proper rain control strategies.
In the last five years, many new EIF systems have entered the market that offer the potential for improved control of rain water penetration. Four classes of rain control design strategy, in order of increasing performance, are commonly available. Face-sealed (FS) perfect barrier systems assume that a perfect barrier to rain penetration is provided at the exterior face (i.e., by the lamina and sealant). Dual barrier (DB) systems assume that the primary face seal may fail, and thus employ a secondary concealed water barrier that covers and protects the substrate. Drained (D) walls assume that the eventual failure of lamina and joints is inevitable, allowing in so much water that a water barrier (like in a DB) and a full drainage system are required. Pressure-moderated (PM) and drained systems build on D systems by adding vents to encourage the moderation of wind pressures across the lamina, thereby reducing the amount of water that penetrates it.
In each of these approaches, all exposed joints should be drained two-stage joints (FS systems are only acceptable with drained joints). Face-sealed EIFS with exposed one-stage joints are not recommended for exterior application over moisture-sensitive substrates. Two-stage joints, in the form of drained sub-sill flashing, are also necessary below windows and at balcony penetrations.
The rain control strategy that should be used generally depends on three primary variables: Exposure--a combination of the climate and the form, size, orientation, and siting of the building; System Quality--a combination of design, materials (including the moisture tolerance of the substrate), workmanship, the confounding effects of weather during installation, and economics; and Performance Expectations--a function of client expectations, minimum code requirements, and so on.
EIFS offer the designer a cladding system with many advantages, but care must be taken to deal with rain penetration issues properly. Face-sealed barrier walls provide a low level of reliability, and should only be used in protected exposures with good design and execution. In many cases a Dual Barrier approach will provide acceptable performance, and drained systems can be used in high exposure applications. Interested readers are encouraged to obtain a copy of CMHC's EIFS Best Practice Guide for more information and detailed drawings and specifications when it is released later this year.
John Straube teaches in the Department of Civil Engineering and the School of Architecture at the University of Waterloo.EIFS, or Exterior Insulated Finishing
The system typically consists of four components:
1) Panels of expanded polystyrene foam insulation glued and screwed to the substrate or vapor barrier.
EIFS Industry Members Association www.eima.com
Legal News about EIFS www.stuccolaw.com
EIFS Alliance www.eifsalliance.com
Stucco cracks https://www.stuccomfgassoc.com/cracks.html
DATELINE INVESTIGATION Is your home crumbling around you? Itís happening to new homes across the country ó find out more from a ëDatelineí investigation NBC NEWS March 22 ó You spend a lot of time looking, do all the legwork, invest your heart and soul in it, not to mention your savings. And finally, you own a piece of the ìAmerican Dreamî ó your own home. But what if the brand new house you worked so hard for begins to crumble around you? Itís happening to new homes around the country. Is it just a case of, ìthey donít build ëem like they used to?î Or is there more to the story? Chief consumer correspondent Lea Thompson reports with a ìDatelineî Investigation.
$20M Stucco Settlement to Benefit N.C. Homeowners. Good article and links to a series by WRAL 5 On Your Side in There are links to the following:
June 11, 1997: Synthetic Stucco Solutions Still have Room for Improvement
Rotting walls prompt ban on use of stucco. Raleigh forbids building with synthetic stucco until January. Officials will set new standards by then. BY MATTHEW EISLEY, Staff Writer RALEIGH -- The City of Raleigh has imposed a moratorium on synthetic stucco on wood-frame buildings because of evidence that it makes walls rot. "It is not in the citizens' interest to continue with a product that is suspect," said Raleigh Inspections Director Ed Owens, who notified home builders last week of a moratorium to last from May 1 until January.
Synthetic Stucco Home Page GAHI Georgia Association of Home Inspectors. Another good source of info. "GAHI is leading the industry with the latest information and testing on the growing problems with EIFS. Check our site often for the latest developments and the best links on the internet."
A Detailed Look at Synthetic Stucco Problems Synthetic stucco is basically a type of foam sheeting glued and nailed to the structural sheathing (usually plywood) on the exterior of a home. This material has a factory- or field-applied fiberglass mesh installed over the outer surface which is then finished with two or more coats of the stucco-like material.
First Synthetic Stucco Lawsuit Filed in Maryland The law firm of Cohen, Milstein, Hausfeld & Toll, P.L.L.C. has filed the first synthetic stucco lawsuit in the state of Maryland. The case, alleging that the plaintiffs' townhouses were damaged by synthetic stucco, was filed in the City Court of Baltimore on December 30, 1998. The lawsuit asserts that synthetic stucco manufactured by Sto Corporation and/or Dryvit Systems, Inc. was defectively designed. Because the synthetic stucco was installed without a drainage system, it has caused water to be trapped between the walls of the townhouses and has caused significant damage.
Welcome to the Information Page for the Ruff v. Parex Class Action Lawsuit and the Senergy and Thoro Settlement. f you own a residence with synthetic stucco exterior wall cladding, your rights may be affected by a class action lawsuit and proposed partial national settlement now pending in court. The Settlement covers: All persons or entities who, as of May 15, 1998, own or owned a one or two family residential dwelling or townhouse in the United States clad with Senergy, Inc.'s or Thoro System Products, Inc.'s EIFS System.
EIFS: Special Report From Builder Online. Exterior Insulation and Finish Systems, EIFS for short, can provide a handsome, low-maintenance, water-resistant cladding -- when applied correctly. But when applied incorrectly, EIFS can become a wood-rotting machine, sealing in moisture that eats away at the home from the inside out.
Homeowners sue builders over stucco Two families in a Weaver Dairy Road subdivision join the furor over synthetic stucco, take the manufacturers and a local custom builder to court. By David Schulman, Staff Writer CHAPEL HILL - Two local homeowners say they got more than gracious architecture with their custom-built $500,000 houses in a Weaver Dairy Road subdivision.
Concerns raised over stucco product By Michele Derus of the Journal Sentinel staff November 28, 1998 As Wisconsin copes with newly discovered decay problems among 4,000 homes sided or sheathed in wood-composite products, synthetic stucco is emerging as the latest allegedly defective building exterior.
$550,000 house may be bulldozed By ANNA GRIFFIN Staff Writer The Charolette Observer. Sometime soon, a demolition crew could arrive to tear down Anna Marie and Alan Nelsen's new home. The house, which they bought for $550,000, is less than five years old and offers stunning views of Lake Norman and The Peninsula Club golf course. But private engineers say it would cost up to $400,000 to make it safe for occupancy.
Synthetic stucco, real damage By Leonora LaPeter Savannah Morning News The siding's tendency to trap water and not let it out leads 23 area homeowners to file suit; at least 3,000 more owners of wooden homes could face damage from the material.
Corev America Inc. - Offers textured architectural coatings and EIFS products. Features product testing information and photo gallery.
Dryvit Systems, Inc. - EIFS materials and related products for industrial, commercial, institutional and residential buildings.
EIFS Facts - Information on commercial and residential EIFS, including case studies, pictures, insurance information, and specifications. Includes a directory of contractors and distributors belonging to the EIFS Industry Members Association (EIMA).
EIFS Legal Network - Legal resource for owners of EIFS or synthetic stucco clad homes. Information on legal recourse for failing EIFS or synthetic stucco.
EIFSweb.com - Resource site for exterior insulation and finish systems used on virtually all types of low rise, mid rise and high rise construction.
Elrey Stucco - Manufacturers of stucco and EIFS wall systems in the southwestern United States.
Master Wall Inc. - Manufacturers of exterior insulation and finish systems, drainage EIFS and textured stucco finishes. Design and technical information.
Pleko - Pleko EIFS provides a durable, insulated, weather resistant and virtually maintenance free building envelope.
Preswitt Mfg. Ltd. - Manufacture and develop acrylic interior and exterior coatings and exterior insulation finish systems.
Senergy, LLC - Manufacture exterior insulation and finish systems, stucco, specialty finishes and architectural coatings for residential and commercial construction. Includes technical data and distributor locator.
Sto Corp. - Multinational manufacturer of EIFS and other specialty construction products. Detailed technical information and links to design and engineering services.
W.G. Adams Corporation - A library of information for homeowners on maintaining and restoring EIFS systems provided by an Atlanta, GA EIFS, stucco and plaster contractor.
Wind-lock Corporation - Supply fastening systems and tools for the EIFS professional. Includes catalogs, material data sheets, and application instructions.
https://www.stocorp.com/webfiles.nsf/view+other+docs/tech+articles+-+engineered+pvc+flashing+for+repair - Window leak repair method
Xlent Equipment - A catalogue of our EIFS spray equipment and adhesive applicator equipment with pictures and details.
Stucco Crack Policy https://www.stuccomfgassoc.com/papers/crack.pdf
EIFS-Stucco Materials and Suppliers
Is Stucco water-resistant? Testing of a cement plaster basecoat has shown that when properly mixed and applied and adequately cured, a 3/4-inch (19 mm) cement plaster membrane is vapor permeable and water-resistant.
A stucco assembly (water-resistant barrier, lath and cement plaster) is classified as a concealed weather-barrier system, which accommodates moisture intrusion that may occur at wall penetrations (windows, vents, etc.). The water-resistant barrier drainage plane between the cement plaster and the substrate directs the moisture, in drainage-fashion, down and out to a weepage point.
An important physical property of a stucco assembly is that it breathes, allowing moisture vapor between the water-resistant barrier and cement plaster to escape through to the outside.
In the design and application of a stucco system, it is important to focus on keeping water out. There always is the possibility that moisture may enter. Therefore, it is reassuring to know that a properly installed drainage plane stucco assembly allows moisture to dry and or drain out.
In order to ensure moisture intrusion does not affect the substrate or structural members of your home all manufacture’s materials installation instructions along with these protocols should be strictly adhered too.
Hot & Humid Climate Building Guide: https://www.buildingscience.com/designsthatwork/hothumid/profiles/maitland.pdf
House wrap Installation Guide: https://www.buildingscience.com/resources/walls/problems_with_housewraps.htm
Lath, Flashing, and Stucco Installation Guide: https://www.opkansas.org/Documents_and_Forms/lath_install.pdf
National One Coat Stucco Association: https://www.nocsa.org/tech.htm
Window Flashing and House wrap Installation Guide: https://www.buildingscience.com/resources/walls/Water_Management_Details-Housewraps_Flashings_Windows.pdf
The Preservation and Repair of Historic Stucco
The term "stucco" is used to describe a type of exterior plaster applied as a two-or-three part coating directly onto masonry, or applied over wood or metal lath to a log or wood frame structure. Stucco is found in many forms on historic structures throughout the United States. It is so common, in fact, that it frequently goes unnoticed, and is often disguised or used to imitate another material. Historic stucco is also sometimes incorrectly viewed as a sacrificial coating, and consequently removed to reveal stone, brick or logs that historically were never intended to be exposed. Age and lack of maintenance hasten the deterioration of many historic stucco buildings. Like most historic building materials, stucco is at the mercy of the elements, and even though it is a protective coating, it is particularly susceptible to water damage. Stucco is a material of deceptive simplicity: in most cases its repair should not be undertaken by a property owner unfamiliar with the art of plastering. Successful stucco repair requires the skill and experience of a professional plasterer. Although several stucco mixes are representative of different periods are provided here for reference Each project is unique, with its own set of problems that require individual solutions
Stucco has been used since ancient times. Still widely used throughout the world, it is one of the most common of traditional building materials. Up until the late 1800's, stucco, like mortar, was primarily lime-based, but the popularization of portland cement changed the composition of stucco, as well as mortar, to a harder material. Historically, the term "plaster" has often been interchangeable with "stucco"; the term is still favored by many, particularly when referring to the traditional lime-based coating. By the nineteenth century "stucco," although originally denoting fine interior ornamental plasterwork, had gained wide acceptance in the United States to describe exterior plastering. "Render" and "rendering" are also terms used to describe stucco, especially in Great Britain. Other historic treatments and coatings related to stucco in that they consist at least in part of a similarly plastic or malleable material include: parging and pargeting, wattle and daub, "cob" or chalk mud, pise de terre, rammed earth, briquete entre poteaux or bousillage, half-timbering, and adobe. All of these are regional variations on traditional mixtures of mud, clay, lime, chalk, cement, gravel or straw. Many are still used today.
Revival Styles Promote Use of Stucco
The introduction of the many revival styles of architecture around the turn of the twentieth century, combined with the improvement and increased availability of portland cement resulted in a "craze" for stucco as a building material in the United States. Beginning about 1890 and gaining momentum into the 1930s and 1940s, stucco was associated with certain historic architectural styles, including: Prairie; Art Deco, and Art Moderne; Spanish Colonial, Mission, Pueblo, Mediterranean, English Cotswold Cottage, and Tudor Revival styles; as well as the ubiquitous bungalow and "four-square" house. The fad for Spanish Colonial Revival, and other variations on this theme, was especially important in furthering stucco as a building material in the United States during this period, since stucco clearly looked like adobe.
Although stucco buildings were especially prevalent in California, the Southwest and Florida, ostensibly because of their Spanish heritage, this period also spawned stucco-coated, revival-style buildings all over the United States and Canada. The popularity of stucco as a cheap, and readily available material meant that by the 1920s, it was used for an increasing variety of building types. Resort hotels, apartment buildings, private mansions and movie theaters, railroad stations, and even gas stations and tourist courts took advantage of the "romance" of period styles, and adopted the stucco construction that had become synonymous with these styles.
A Practical Building Material
Stucco has traditionally been popular for a variety of reasons. It was an inexpensive material that could simulate finely dressed stonework, especially when "scored" or "lined" in the European tradition. A stucco coating over a less finished and less costly substrate such as rubblestone, fieldstone, brick, log or wood frame, gave the building the appearance of being a more expensive and important structure. As a weather-repellent coating, stucco protected the building from wind and rain penetration, and also offered a certain amount of fire protection. While stucco was usually applied during construction as part of the building design, particularly over rubblestone or fieldstone, in some instances it was added later to protect the structure, or when a rise in the owner's social status demanded a comparable rise in his standard of living.
Composition of Historic Stucco
Before the mid-to-late nineteenth century, stucco consisted primarily of hydrated or slaked lime, water and sand, with straw or animal hair included as a binder. Natural cements were frequently used in stucco mixes after their discovery in the United States during the 1820s. Portland cement was first manufactured in the United States in 1871, and it gradually replaced natural cement. After about 1900, most stucco was composed primarily of portland cement, mixed with some lime. With the addition of portland cement, stucco became even more versatile and durable. No longer used just as a coating for a substantial material like masonry or log, stucco could now be applied over wood or metal lath attached to a light wood frame. With this increased strength, stucco ceased to be just a veneer and became a more integral part of the building structure.
Today, gypsum, which is hydrated calcium sulfate or sulfate of lime, has to a great extent replaced lime Gypsum is preferred because it hardens faster and has less shrinkage than lime. Lime is generally used only in the finish coat in contemporary stucco work.
The composition of stucco depended on local custom and available materials. Stucco often contained substantial amounts of mud or clay, marble or brick dust, or even sawdust, and an array of additives ranging from animal blood or urine, to eggs, keratin or gluesize (animal hooves and horns), varnish, wheat paste, sugar, salt, sodium silicate, alum, tallow, linseed oil, beeswax, and wine, beer, or rye whiskey. Waxes, fats and oils were included to introduce water-repellent properties, sugary materials reduced the amount of water needed and slowed down the setting time, and alcohol acted as an air entrainer. All of these additives contributed to the strength and durability of the stucco.
The appearance of much stucco was determined by the color of the sand--or sometimes burnt clay--used in the mix, but often stucco was also tinted with natural pigments, or the surface whitewashed or color-washed after stuccoing was completed. Brick dust could provide color, and other coloring materials that were not affected by lime, mostly mineral pigments, could be added to the mix for the final finish coat. Stucco was also marbled or marbleized--stained to look like stone by diluting oil of vitriol (sulfuric acid) with water, and mixing this with a yellow ochre, or another color. As the twentieth century progressed, manufactured or synthetic pigments were added at the factory to some prepared stucco mixes.
Methods of Application
Stucco is applied directly, without lath, to masonry substrates such as brick, stone, concrete or hollow tile. But on wood structures, stucco, like its interior counterpart plaster, must be applied over lath in order to obtain an adequate key to hold the stucco. Thus, when applied over a log structure, stucco is laid on horizontal wood lath that has been nailed on vertical wood furring strips attached to the logs. If it is applied over a wood frame structure, stucco may be applied to wood or metal lath nailed directly to the wood frame; it may also be placed on lath that has been attached to furring strips. The furring strips are themselves laid over building paper covering the wood sheathing.
Like interior wall plaster, stucco has traditionally been applied as a multiple-layer process, sometimes consisting of two coats, but more commonly as three. Whether applied directly to a masonry substrate or onto wood or metal lath, this consists of a first "scratch" or "pricking-up" coat, followed by a second scratch coat, sometimes referred to as a "floating" or "brown" coat, followed finally by the "finishing" coat. Up until the late-nineteenth century, the first and the second coats were of much the same composition, generally consisting of lime, or natural cement, sand, perhaps clay, and one or more of the additives previously mentioned. Straw or animal hair was usually added to the first coat as a binder. The third, or finishing coat, consisted primarily of a very fine mesh grade of lime and sand, and sometimes pigment. As already noted, after the 1820s, natural cement was also a common ingredient in stucco until it was replaced by portland cement. Both masonry and wood lath must be kept wet or damp to ensure a good bond with the stucco. Wetting these materials helps to prevent them from pulling moisture out of the stucco too rapidly, which results in cracking, loss of bond, and generally poor quality stuccowork.
Traditional Stucco Finishes
Until the early-twentieth century when a variety of novelty finishes or textures were introduced, the last coat of stucco was commonly given a smooth, troweled finish, and then scored or lined in imitation of ashlar. The illusion of masonry joints was sometimes enhanced by a thin line of white lime putty, graphite, or some other pigment. Some nineteenth century buildings feature a water table or raised foundation of roughcast stucco that differentiates it from the stucco surface above, which is smooth and scored. Other novelty or textured finishes associated with the "period" or revival styles of the early-twentieth century include: the English cottage finish, adobe and Spanish, pebble-dashed or dry-dash surface, fan and sponge texture, reticulated and vermiculated, roughcast (or wet dash), and sgraffito.
Although A. J. Downing alluded to stuccoed houses in Pennsylvania that had survived for over a century in relatively good condition, historic stucco is inherently not a particularly permanent or long-lasting building material. Regular maintenance is required to keep it in good condition. Unfortunately, many older or historic buildings are not always accorded this kind of care.
Because building owners knew stucco to be a protective, but also somewhat fragile coating, they employed a variety of means to prolong its usefulness. The most common treatment was to whitewash stucco, often annually. The lime in the whitewash offered protection and stability and helped to harden the stucco. Most importantly, it filled hairline cracks before they could develop into larger cracks and let in moisture. To improve water repellency, stucco buildings were also sometimes coated with paraffin, another type of wax, or other stucco-like coatings, such as oil mastics.
Most stucco deterioration is the result of water infiltration into the building structure, either through the roof, around chimneys, window and door openings, or excessive ground water or moisture penetrating through, or splashing up from the foundation. Potential causes of deterioration include: ground settlement lintel and door frame settlement, inadequate or leaking gutters and downspouts, intrusive vegetation, moisture migration within walls due to interior condensation and humidity, vapor drive problems caused by furnace, bathroom and kitchen vents, and rising damp resulting from excessive ground water and poor drainage around the foundation. Water infiltration will cause wood lath to rot, and metal lath and nails to rust, which eventually will cause stucco to lose its bond and pull away from its substrate.
After the cause of deterioration has been identified, any necessary repairs to the building should be made first before repairing the stucco. Such work is likely to include repairs designed to keep excessive water away from the stucco, such as roof, gutter, downspout and flashing repairs, improving drainage, and redirecting rainwater runoff and splash-back away from the building. Horizontal areas such as the tops of parapet walls or chimneys are particularly vulnerable to water infiltration, and may require modifications to their original design, such as the addition of flashing to correct the problem.
Previous repairs inexpertly carried out may have caused additional deterioration, particularly if executed in portland cement, which tends to be very rigid, and therefore incompatible with early, mostly soft lime-based stucco that is more "flexible." Incompatible repairs, external vibration caused by traffic or construction, or building settlement can also result in cracks which permit the entrance of water and cause the stucco to fail.
Before beginning any stucco repair, an assessment of the stucco should be undertaken to determine the extent of the damage, and how much must be replaced or repaired. Testing should be carried out systematically on all elevations of the building to determine the overall condition of the stucco. Some areas in need of repair will be clearly evidenced by missing sections of stucco or stucco layers. Bulging or cracked areas are obvious places to begin. Unsound, punky or soft areas that have lost their key will echo with a hollow sound when tapped gently with a wooden or acrylic hammer or mallet.
Identifying the Stucco Type
Analysis of the historic stucco will provide useful information on its primary ingredients and their proportions, and will help to ensure that the new replacement stucco will duplicate the old in strength, composition, color and texture as closely as possible. However, unless authentic, period restoration is required, it may not be worthwhile, nor in many instances possible, to attempt to duplicate all of the ingredients (particularly some of the additives), in creating the new stucco mortar. Some items are no longer available, and others, notably sand and lime--the major components of traditional stucco--have changed radically over time. For example, most sand used in contemporary masonry work is manufactured sand, because river sand, which was used historically, is difficult to obtain today in many parts of the country. The physical and visual qualities of manufactured sand versus river sand, are quite different, and this affects the way stucco works, as well as the way it looks. The same is true of lime, which is frequently replaced by gypsum in modern stucco mixes. And even if identification of all the items in the historic stucco mix were possible, the analysis would still not reveal how the original stucco was mixed and applied.
There are, however, simple tests that can be carried out on a small piece of stucco to determine its basic makeup. A dilute solution of hydrochloric (muriatic) acid will dissolve lime-based stucco, but not portland cement. Although the use of portland cement became common after 1900, there are no precise cutoff dates, as stuccoing practices varied among individual plasterers, and from region to region. Some plasterers began using portland cement in the 1880s, but others may have continued to favor lime stucco well into the early twentieth century. While it is safe to assume that a late-eighteenth or early-nineteenth century stucco is lime-based, late-nineteenth or early-twentieth century stucco may be based on either lime or portland cement. Another important factor to take into consideration is that an early lime-stucco building is likely to have been repaired many times over the ensuing years, and it is probable that at least some of these patches consist of portland cement.
Planning the Repair
Once the extent of damage has been determined, a number of repair options may be considered. Small hairline cracks usually are not serious and may be sealed with a thin slurry coat consisting of the finish coat ingredients, or even with a coat of paint or whitewash.
Commercially available caulking compounds are not suitable materials for patching hairline cracks. Because their consistency and texture is unlike that of stucco, they tend to weather differently, and attract more dirt; as a result, repairs made with caulking compounds may be highly visible, and unsightly. Larger cracks will have to be cut out in preparation for more extensive repair. Most stucco repairs will require the skill and expertise of a professional plasterer.
In the interest of saving or preserving as much as possible of the historic stucco, patching rather than wholesale replacement is preferable. When repairing heavily textured surfaces, it is not usually necessary to replace an entire wall section, as the textured finish, if well-executed, tends to conceal patches, and helps them to blend in with the existing stucco. However, because of the nature of smooth-finished stucco, patching a number of small areas scattered over one elevation may not be a successful repair approach unless the stucco has been previously painted, or is to be painted following the repair work. On unpainted stucco such patches are hard to conceal, because they may not match exactly or blend in with the rest of the historic stucco surface. For this reason it is recommended, if possible, that stucco repair be carried out in a contained or well-defined area, or if the stucco is scored, the repair patch should be "squared-off" in such a way as to follow existing scoring. In some cases, especially in a highly visible location, it may be preferable to restucco an entire wall section or feature. In this way, any differences between the patched area and the historic surface will not be so readily apparent.
Repair of historic stucco generally follows most of the same principles used in plaster repair. First, all deteriorated, severely cracked and loose stucco should be removed down to the lath (assuming that the lath is securely attached to the substrate), or down to the masonry if the stucco is directly applied to a masonry substrate. A clean surface is necessary to obtain a good bond between the stucco and substrate. The areas to be patched should be cleaned of all debris with a bristle brush, and all plant growth, dirt, loose paint, oil or grease should be removed. If necessary, brick or stone mortar joints should then be raked out to a depth of approximately 5/8" to ensure a good bond between the substrate and the new stucco.
To obtain a neat repair, the area to be patched should be squared-off with a butt joint, using a cold chisel, a hatchet, a diamond blade saw, or a masonry bit. Sometimes it may be preferable to leave the area to be patched in an irregular shape which may result in a less conspicuous patch. Proper preparation of the area to be patched requires very sharp tools, and extreme caution on the part of the plasterer not to break keys of surrounding good stucco by "over-sounding" when removing deteriorated stucco.To ensure a firm bond, the new patch must not overlap the old stucco. If the stucco has lost its bond or key from wood lath, or the lath has deteriorated or come loose from the substrate, a decision must be made whether to try to reattach the old lath, to replace deteriorated lath with new wood lath, or to leave the historic wood lath in place and supplement it with modern expanded metal lath. Unless authenticity is important, it is generally preferable (and easier) to nail new metal lath over the old wood lath to support the patch. Metal lath that is no longer securely fastened to the substrate may be removed and replaced in kind, or left in place, and supplemented with new wire lath.
When repairing lime-based stucco applied directly to masonry, the new stucco should be applied in the same manner, directly onto the stone or brick. The stucco will bond onto the masonry itself without the addition of lath because of the irregularities in the masonry or those of its mortar joints, or because its surface has been scratched, scored or otherwise roughened to provide an additional key. Cutting out the old stucco at a diagonal angle may also help secure the bond between the new and the old stucco. For the most part it is not advisable to insert metal lath when restuccoing historic masonry in sound condition, as it can hasten deterioration of the repair work. Not only will attaching the lath damage the masonry, but the slightest moisture penetration can cause metal lath to rust. This will cause metal to expand, eventually resulting in spalling of the stucco, and possibly the masonry substrate too.
If the area to be patched is properly cleaned and prepared, a bonding agent is usually not necessary. However, a bonding agent may be useful when repairing hairline cracks, or when dealing with substrates that do not offer a good bonding surface. These may include dense stone or brick, previously painted or stuccoed masonry, or spalling brick substrates. A good mechanical bond is always preferable to reliance on bonding agents. Bonding agents should not be used on a wall that is likely to remain damp or where large amounts of salts are present. Many bonding agents do not survive well under such conditions, and their use could jeopardize the longevity of the stucco repair.
A stucco mix compatible with the historic stucco should be selected after analyzing the existing stucco. It can be adapted from a standard traditional mix of the period, or based on one of the mixes included here. Stucco consisting mostly of portland cement generally will not be physically compatible with the softer, more flexible lime-rich historic stuccos used throughout the eighteenth and much of the nineteenth centuries. The differing expansion and contraction rates of lime stucco and portland cement stucco will normally cause the stucco to crack. Choosing a stucco mix that is durable and compatible with the historic stucco on the building is likely to involve considerable trial and error, and probably will require a number of test samples, and even more if it is necessary to match the color. It is best to let the stucco test samples weather as long as possible--ideally one year, or at least through a change of seasons, in order to study the durability of the mix and its compatibility with the existing stucco, as well as the weathering of the tint if the building will not be painted and color match is an important factor.If the test samples are not executed on the building, they should be placed next to the stucco remaining on the building to compare the color, texture and composition of the samples with the original. The number and thickness of stucco coats used in the repair should also match the original.
After thoroughly dampening the masonry or wood lath, the first, scratch coat should be applied to the masonry substrate, or wood or metal lath, in a thickness that corresponds to the original if extant, or generally about 1/4" to 3/8". The scratch coat should be scratched or crosshatched with a comb to provide a key to hold the second coat. It usually takes 24-72 hours, and longer in cold weather, for each coat to dry before the next coat can be applied. The second coat should be about the same thickness as the first, and the total thickness of the first two coats should generally not exceed about 5/8". This second or leveling coat should be roughened using a wood float with a nail protruding to provide a key for the final or finish coat. The finish coat, about 1/4" thick, is applied after the previous coat has initially set. If this is not feasible, the base coat should be thoroughly dampened when the finish coat is applied later. The finish coat should be worked to match the texture of the original stucco.
Colors and Tints for Historic Stucco Repair
The color of most early stucco was supplied by the aggregate included in the mix--usually the sand. Sometimes natural pigments were added to the mix, and eighteenth and nineteenth-century scored stucco was often marbleized or painted in imitation of marble or granite. Stucco was also frequently coated with whitewash or a colorwash. This tradition later evolved into the use of paint, its popularity depending on the vagaries of fashion as much as a means of concealing repairs. Because most of the early colors were derived from nature, the resultant stucco tints tended to ne mostly earth-toned. This was true until the advent of brightly colored stucco in the early decades of the twentieth century. This was the so-called "Jazz Plaster" developed by O.A. Malone, the "man who put color into California," and who founded the California Stone Products Corporation in 1927. California Stucco was revolutionary for its time as the first stucco/plaster to contain colored pigment in its pre-packaged factory mix.
When patching or repairing a historic stucco surface known to have been tinted, it may be possible to determine through visual or microscopic analysis whether the source of the coloring is sand, cement, or pigment. Although some pigments or aggregates used traditionally may no longer be available, a sufficiently close color-match can generally be approximately using sand, natural or mineral pigments, or a combination of these. Obtaining such a match will require testing and comparing the color of the dried test samples with the original. Successfully combining pigments in the dry stucco mix prepared for the finish coat requires considerable skill. The amount of pigment must be carefully measured for each batch of stucco. Overworking the mix can make the pigment separate from the lime. Changing the amount of water added to the mix, or using water to apply the tinted finish coat, will also affect the color of the stucco when it dries.
Generally, the color obtained by hand-mixing these ingredients will provide a sufficiently close match to cover an entire wall or an area distinct enough from the rest of the structure that the color differences will not be obvious. However, it may not work for small patches conspicuously located on a primary elevation, where color differences will be especially noticeable. In these instances, it may be necessary to conceal the repairs by painting the entire patched elevation, or even the whole building.
Many stucco buildings have been painted over the years and will require repainting after the stucco repairs have been made. Limewash or cement-based paint, latex paint, or oil-based paint are appropriate coatings for stucco buildings. The most important factor to consider when repainting a previously painted or coated surface is that the new paint be compatible with any coating already on the surface. In preparation for repainting, all loose or peeling paint or other coating material not firmly adhered to the stucco must be removed by hand-scraping or natural bristle brushes. The surface should then be cleaned.
Cement-based paints, most of which today contain some portland cement and are really a type of limewash, have traditionally been used on stucco buildings. The ingredients were easily obtainable. Furthermore, the lime in such paints actually bonded or joined with the stucco and provided a very durable coating. In many regions, whitewash was applied annually during spring cleaning. Modern, commercially available premixed masonry and mineral-based paints may also be used on historic stucco buildings.
If the structure must be painted for the first time to conceal repairs, almost any of these coatings may be acceptable depending on the situation. Latex paint, for example, may be applied to slightly damp walls or where there is an excess of moisture, but latex paint will not stick to chalky or powdery areas. Oil-based, or alkyd paints must be applied only to dry walls; new stucco must cure up to a year before it can be painted with oil-based paint.
Contemporary Stucco Products
There are many contemporary stucco products on the market today. Many of them are not compatible, either physically or visually, with historic stucco buildings. Such products should be considered for use only after consulting with a historic masonry specialist. However, some of these prepackaged tinted stucco coatings may be suitable for use on stucco buildings dating from the late-nineteenth or early-twentieth century, as long as the color and texture are appropriate for the period and style of the building. While some masonry contractors may, as a matter of course, suggest that a water-repellent coating be applied after repairing old stucco, in most cases this should not be necessary, since color washes and paints serve the same purpose, and stucco itself is a protective coating.
Cleaning Historic Stucco Surfaces
Historic stucco buildings often exhibit multiple layers of paint or limewash. Although some stucco surfaces may be cleaned by water washing, the relative success of this procedure depends on two factors: the surface texture of the stucco, and the type of dirt to be removed. If simply removing airborne dirt, smooth unpainted stucco, and heavily-textured painted stucco may sometimes be cleaned using a low-pressure water wash, supplemented by scrubbing with soft natural bristle brushes, and possibly non-ionic detergents. Organic plant material, such as algae and mold, and metallic stains may be removed from stucco using poultices and appropriate solvents. Although these same methods may be employed to clean unpainted roughcast, pebble-dash, or any stucco surface featuring exposed aggregate, due to the surface irregularities, it may be difficult to remove dirt, without also removing portions of the decorative textured surface. Difficulty in cleaning these surfaces may explain why so many of these textured surfaces have been painted.
When Total Replacement is Necessary
Complete replacement of the historic stucco with new stucco of either a traditional or modern mix will probably be necessary only in cases of extreme deterioration-- that is, a loss of bond on over 40-50 percent of the stucco surface. Another reason for total removal might be that the physical and visual integrity of the historic stucco has been so compromised by prior incompatible and ill-conceived repairs that patching would not be successful.
When stucco no longer exists on a building there is more flexibility in choosing a suitable mix for the replacement. Since compatibility of old and new stucco will not be an issue, the most important factors to consider are durability, color, texture and finish. Depending on the construction and substrate of the building, in some instances it may be acceptable to use a relatively strong cement-based stucco mortar. This is certainly true for many late-nineteenth and early-twentieth century buildings, and may even be appropriate to use on some stone substrates even if the original mortar would have been weaker, as long as the historic visual qualities noted above have been replicated. Generally, the best principle to follow for a masonry building is that the stucco mix, whether for repair or replacement of historic stucco, should be somewhat weaker than the masonry to which it is to be applied in order not to damage the substrate.
General Guidance for Historic Stucco Repair
A skilled professional plasterer will be familiar with the properties of materials involved in stucco repair and will be able to avoid some of the pitfalls that would hinder someone less experienced. General suggestions for successful stucco repair parallel those involving restoration and repair of historic mortar or plaster. In addition, the following principles are important to remember:
Historic Stucco Textures
Most of the oldest stucco in the U.S. dating prior to the late-nineteenth century, will generally have a smooth, troweled finish (sometimes called a sand or float finish), possibly scored to resemble ashlar masonry units. Scoring may be incised to simulate masonry joints, the scored lines may be emphasized by black or white penciling, or the lines may simply be drawn or painted on the surface of the stucco. In some regions, at least as early as the first decades of the nineteenth century, it was not uncommon to use a roughcast finish on the foundation or base of an otherwise smooth-surfaced building. Roughcast was also used as an overall stucco finish for some outbuildings, and other less important types of structures.
A wide variety of decorative surface textures may be found on revival style stucco buildings, particularly residential architecture. These styles evolved in the late-nineteenth century and peaked in popularity in the early decades of the twentieth century. Frank Lloyd Wright favored a smooth finish stucco, which was imitated on much of the Prairie style architecture inspired by his work. Some of the more picturesque surface textures include: English Cottage or English Cotswold finish; sponge finish; fan texture; adobe finish; and Spanish or Italian finish. Many of these finishes and countless other regional and personalized variations on them are still in use.
The most common early-twentieth century stucco finishes are often found on bungalow-style houses, and include: spatter or spatterdash (sometimes called roughcast, harling, or wetdash), and pebble-dash or drydash. The spatterdash finish is applied by throwing the stucco mortar against the wall using a whisk broom or a stiff fiber brush, and it requires considerable skill on the part of the plasterer to achieve a consistently rough wall surface. The mortar used to obtain this texture is usually composed simply of a regular sand, lime, and cement mortar, although it may sometimes contain small pebbles or crushed stone aggregate, which replaces one-half the normal sand content. The pebble-dash or drydash finish is accomplished manually by the plasterer throwing or "dashing" dry pebbles (about 1/8" to 1/4" in size), onto a coat of stucco freshly applied by another plasterer. The pebbles must be thrown at the wall with a scoop with sufficient force and skill that they will stick to the stuccoed wall. A more even or uniform surface can be achieved by patting the stones down with a wooden float. This finish may also be created using a texturing machine.
Stucco on historic buildings is especially vulnerable not only to the wear of time and exposure to the elements, but also at the hands of well-intentioned "restorers," who may want to remove stucco from eighteenth and nineteenth century structures, to expose what they believe to be the original or more "historic" brick, stone or log underneath. Historic stucco is a character-defining feature and should be considered an important historic building material, significant in its own right. While many eighteenth and nineteenth century buildings were stuccoed at the time of construction, others were stuccoed later for reasons of fashion or practicality. As such, it is likely that this stucco has acquired significance over time, as part of the history and evolution of a building. Thus, even later, non-historic stucco should be retained in most instances; and similar logic dictates that new stucco should not be applied to a historic building that was not stuccoed previously. When repairing historic stucco, the new stucco should duplicate the old as closely as possible in strength, composition, color and texture.
What is composite wood siding?
There have been well over 100 different types of wood composite sidings manufactured in the last fifty years. They have been manufactured to look like horizontal lap siding, panel (T1-11) siding, board & batten siding, cedar shingle siding, and just about anything else available in real wood.
Most wood composite siding products are made with wood by-products such as Orientated Strand Board (OSB) (also known as Wafer Wood) or sawdust. The by-products are generally mixed with resins and pressed together to make panels typically 3/8" to 5/8" thick. Next, faux wood-grain embossed overlays are adhered to the face of the panels with resin and heat. Finally, the large panels are cut into smaller panels or lap siding.
There are hundreds of potential siding related problems. However, siding problems could be the result of poor installation, extreme weather exposure, improper nailing, inadequate flashing, poor paint coverage, inappropriate caulking, fungal growth, or delayed maintenance. These are just a few samples of what might be causing your siding problems. The bottom line is you have a problem that needs to be addressed before it leads to more significant problems, costs, or headaches.
Various Siding Markings
Often referred to as Georgia-Pacific®, Weyerhaeuser® or Masonite® siding, this type of siding is made by numerous different manufacturers. Each company's fiberboard is made in roughly the same manner and tends to have the same problems.
After this siding has been installed for some length of time it tends to expand slightly. This causes the area around the nail heads to become damaged, this allows moisture to penetrate the board and deteriorate the paneling.
As the moisture level rises, the board’s edges tend to expand breaking the paint, which, in turn, allows rainwater to be absorbed causing a breakdown of the glue and deterioration of the product.
Hardboard planking also tends to shrink and swell along its length, breaking the seal where the boards’ joins have been caulked during installation, leaving them vulnerable to water penetration.
It is very important that the caulking on this hardboard type siding is maintained in good condition. Regular repainting of the home is strongly recommended even though the previous paint may appear to be in good condition.
It may be possible to slow down the deterioration of this siding by regular painting and caulking; however, home owners should be aware that there will be problems with their siding in the future.
Identifying Various Siding Markings
Facts about residing over composite panel (T1-11) siding
June, 2001, Source: Bill Jacob - Former LP employee and consultant
There are severe problems associated with installing new siding over defective wood composite panel (T1-11) siding or any other type of defective siding.
Manufacturers: Louisiana-Pacific Corp., Masonite Corp., and Weyerhaeuser Corp.
Product Names: Inner-Seal Panel Siding, Omniwood Panel Siding, Weyerhaeuser Panel Siding
Other Names: T1-11 Siding, Sheet Siding, and Composite Panel Siding
Physical Description: Four-foot wide sheets of wood composite panels (similar to plywood) manufactured in eight, nine, and ten-foot lengths. Panels range in thickness from 3/8" to 5/8", however most panels are 7/16" (before swelling). Panels have either smooth, stucco, or wood-grain embossed surfaces. Some wood-grain panels have vertical grooves spaced every four to eight inches.
Problem: All panel siding must be removed and replaced during the residing process. If it is not removed, it will continue to deteriorate and cause future problems. Most siding companies mislead customers by claiming they can install new siding over defective panel siding. Some also claim they can kill any and all current and future toxic fungal growth by treating the surface of panel siding with a fungicide, bottom edge sealant, or borax rod treatment. However, most panel siding problems, such as dry-rot and toxic fungus growth, lay underneath the surface of panel siding and cannot be detected or eliminated without removing all of the panel siding. In addition, most new siding warranties will be voided if you install new siding over defective panel siding. They have limitations that explicitly exclude failure due to defects in the underlying structural sheathing, framing, or substrate (the material you're siding is nailed to).
Consequences: If you apply siding over composite T1-11 and later decide to sell your house, you may need to disclose this information to your realtor and any potential buyers. Failure to disclose this could result in future liabilities for all parties involved.
Acceptable Replacement Methods: There are two safe and acceptable ways to replace defective composite T1-11 panel siding. The first way is to simply remove it and replace it with a quality real wood panel T1-11. The second way is to remove it, install new sheathing, install new moisture barrier, and install another siding material instead of T1-11.
I encourage you to accompany your inspector so that you may ask questions and gain a better understanding of the systems located at the property.
If you have any questions, or are interested in any other services, please contact us so we may discuss your specific needs