Stucco Repair

The repair of stucco should begin by identifying the cause of the damage to the stucco finish. Historically, the application of stucco was quite similar to the process of applying lime plaster. Repairs should be carried out as soon as problems become visible, as the damage will only become worse over time. Cracks may form in the stucco due to building settling or direct damage to the exterior coating. Once water is able to breach the coating, whether through an opening in the stucco itself or from beneath its surface, stucco can begin to buckle and crumble. Wood is a common structural material that is often used as substrate beneath stucco. It can absorb moisture from at or below ground level and draw it away from the original source of the problem.

Preparing for the repair process requires testing to determine the composition of the stucco that is to be repaired. Due to numerous factors, including regionally available materials and original workmanship, there is a variety of materials that may have been used for the original application of stucco.

It must also be determined if the type of stucco used is lime-based or Portland cement-based. Of particular concern is the use of Portland cement, which is harder than previous methods used in stucco application. This material is not compatible with softer and more flexible lime cement that was used in the 18th and into the mid-19th centuries. Test sampling is critical to determine the best mixture, in terms of durability, compatibility, texture and color to use in the repair process. Test patches should be used to help make this determination. The same number of layers should be used in the repair as were used in the original stucco application.

A professional plasterer or contractor familiar with the process of making repairs to stucco should carry out necessary repairs. Typically, a homeowner should not attempt to repair stucco finishes on their own.

Further research that should be conducted prior to the commencement of repair includes determining the types of ingredients used in the original stucco so that the color and texture of the original material can be matched as closely as possible. In some cases, shells or pebbles were used in the stucco covering. Regionally sourced sand, for example, may have been used in the original application, but may no longer be readily available. In this way, stucco tended to be tinted directly, although sometimes it was painted after being applied.

Sand and cement stucco

As a building material, stucco is a durable, attractive, and weather-resistant wall covering. It was traditionally used as both an interior and exterior finish applied in one or two thin layers . The finish coat usually contained an integral color and was typically textured for appearance.

Then with the introduction and development of heavy timber and light wood-framed construction methods, stucco was adapted for this new use by adding a lath, attached to and spanning between the structural supports and by increasing the thickness and number of layers of the total system. The lath added support for the wet plaster and tensile strength to the brittle, cured stucco; while the increased thickness and number of layers helped control cracking. The application of stucco and lath occurs in three coats — the scratch coat, the brown coat and the finish coat. The two base coats of plaster are hand-applied . The finish coat can be troweled smooth, hand- textured, floated to a sand finish.

Originally the lath material was strips of wood installed horizontally on the wall, with spaces between, that would support the wet plaster until it cured. This lath and plaster technique became widely used. In exterior wall applications, the lath is installed over a weather-resistant asphalt-impregnated felt or paper sheet that protects the framing from the moisture that can pass through the porous stucco.

Following World War II, the introduction of metal wire mesh, or netting, replaced the use of wood lath. Galvanizing the wire made it corrosion resistant and suitable for exterior wall applications. At the beginning of the 21st century, this “application” method of wire mesh lath and three coats of exterior plaster is still widely used.

Eifs

Exterior Insulation and Finishing System (EIFS) is a type of building exterior wall cladding system that provides exterior walls with an insulated finished surface and waterproofing in an integrated composite material system. Although often called “synthetic stucco”, EIFS is not stucco. There are a number of versions of EIFS. The most basic and common EIFS is called a barrier EIFS (also known as a traditional or conventional EIFS). Another type is called EIFS with Drainage, which is a barrier EIFS to which a water drainage capability has been added. Another benefit of EIFS is the option to add architectural details that are composed of the same materials. EIFS mouldings or as they are commonly referred to, stucco mouldings, come in a large variety of shapes and sizes. They are widely used on residential and commercial projects in North America and are gaining popularity worldwide. EIFS is typically attached to the outside face of exterior walls with an adhesive or mechanical fasteners. Adhesives are commonly used to attach EIFS to gypsum board, cement board, or concrete substrates.

EIFS consists of a number of layers that are installed in the following order. The most basic EIFS (a barrier EIFS) consists of 4 layers:

  1. The first layer is a High Performance, Non-cementitious Water-Resistive Membrane and Vapor Barrier.
  2. Next is a layer of foam insulation (also called simply “foam”) that comes in the form of sheets. Most EIFS use a type of insulation called Expanded Polystyrene, also known as EPS.
  3. The third is a reinforced layer that is applied onto the face of the insulation, consisting of a fiberglass reinforcing mesh embedded in a cement adhesive (known as the base coat).
  4. A final topcoat which is a colored, textured paint-like material that is applied with a trowel or, very rarely, by spraying. A wide range of colors and textures are available as well as custom colors. Available textures include smooth surfaces or rough “stucco-like” textures .

Exterior Stucco Painting

Exposure to sunlight (ultraviolet radiation) and moisture are the major factors affecting the durability of paint coatings and the durability of the substrate. Ultraviolet radiation, moisture and heat can each lead to the breakdown of the resin in painted surfaces which binds (holds) the pigment to the substrate surface.

Paint has to:

• keep rain out of substrates
• breathe when it’s on the outside
• protect substrates from getting a sunburn
• look nice

Exposure to sunlight (ultraviolet radiation), moisture and heat are the major factors affecting the durability of paint coatings and the durability of substrates (wood, plastics, etc.). Recall that UV, water and heat are “damage functions.” Although, each factor can independently lead to deterioration, the effect of the combination of the three factors is much more severe than each factor separately. Ultraviolet radiation, moisture and heat can each lead to the breakdown of the resin in painted surfaces which binds (holds) the pigment to the substrate surface. When the resin breaks down, pigment is lost (washed away from the surface) and fading occurs. In some instances, rubbing the surface with a cloth or a hand will remove a white powder from the paint surface (chalking).

A paint coating’s resistance to ultraviolet radiation and moisture is dependent on the ratio of resin to pigment in the paint. The more resin available to completely coat a pigment particle, the more forcefully the particle is bound to a surface. Premium paints have a high ratio of resin to pigment. A low cost paint typically has a high pigment content relative to resin content as pigment is less expensive than resin. Although a high pigment content paint has an excellent “hiding” ability, high pigment content paints with low resin contents are unable to resist expopermesure to sunlight and moisture.

Parging

The term ‘parge coat’ refers to the application of a thin coat of a cementitious or polymeric mortar to concrete or masonry walls. A parge coat can reduce air leakage through cracks, joints and porous wall constructions and so reduce energy consumption and improve comfort and acoustic performance. It can also be used to prepare a surface for a topcoat.

What is Parging?

The process of parging generally refers to the application of a cement coating, which is applied over a wall surface, such as over a foundation, or exterior wall. Most common is the process of parging over a concrete foundation.

What is the purpose of parging?

Parging cement can have several variations in terms of the elements used in the particular concrete mixture used. Such elements can include latex based colours, fiber materials designed to add strength, or different mix ratios in the concrete itself, depending on the purpose of the application. Such work typically falls in the domain of the mason’s craft. Exposed portions of foundations which are visible above grade, are commonly parged to provide extra protection for the poured concrete, or block construction foundation walls. It also results in a neat finished appearance.

Other examples of parging can be observed on an exterior garden or retaining walls, and on exterior structural walls .

A skilled Plaster makes parging look simple; but it requires considerable practice to achieve a smooth appearance. Textured appearances may also be achieved by adding such materials as pebbles or smooth rocks applied to cement coating materials.

Masonry

Interior or exterior, structural or cosmetic, We have the qualification, knowledge, and experience to provide you with the best quality stone masonry and bricklaying services available in Calgary. Our staff have the training and experience necessary to provide you with professional workmanship that will absolutely exceed your expectations.

If you have ideas you would like to speak with us about concerning a new masonry project, or repair/maintenance of an existing one, feel free to contact us. Our input is strictly no-obligation, as are our consultations.

We offers a variety of high quality residential masonry services throughout Calgary and the surrounding areas. From fireplace refacing to brick veneer that can be installed on interior stud walls, We can enhance the look of your home, inside and outside. Whether your home is a heritage home or brand new our team will work to ensure the design and details fit naturally within the style of your home, allowing for a natural flow throughout the home.

If you already have an idea or would like to learn more about our masonry services contact us today to learn more about our offerings, what is best for your home’s need or to begin discussing future plans.

From the outside of your home to the inside we are equipped and qualified to handle all of your residential masonry needs. Contact us to for a quote on your next home masonry project.