Common Stucco Terms

Below is a list of common stucco terms and phrases used in the stucco industry and throughout this website. The intention is to both define and explain the use of certain products and procedures. If you have questions, please contact us.

Aggregate – Sand that is added to the stucco mixture.

Aerating/Aeration – The process of puncturing holes into a stucco wall to allow moisture inside the wall to drain out and evaporate.

Backer Rod – A round foam piece that is placed into openings to fill the hole where caulking is needed. Its round shape creates a convex application of the caulking reducing the thickness of the caulking at the center of the caulked channel. The combination of backer rod and caulking creates a better caulking application because the caulking contracts and expands at its weakest point, in the middle of the channel. Without the backer rod, the caulking can pull away from either side of the channel that has the least amount of adhesion.

Base Coat – A thin coating of cement used to attach foam shapes to a concrete wall as well as to coat the entire surface prior to applying a finish texture coating. Primarily used in EIFS applications, but is also used to repair cracks in conventional stucco.

Brown Coat – The second coat of concrete applied on top of the scratch coat in a conventional stucco application.  The brown coat is smoother than the scratch coat so that stucco may be applied smoothly on top in the finish coat.

Caulking – The purpose of caulking is to create a barrier that prevents moisture from entering behind the exterior surface. Caulking is only as good as the surface that it is applied to. For example, if caulking is applied between the stucco and a painted wood surface, if the paint on the wood surface starts to peel, then the caulking will fail as well. Master Stucco uses urethane caulks, which are oil-based and have longer life spans. Water-based caulks (silicone caulks) tend to fail faster, are affected by UV light, and in some cases, do not offer a good surface for paint to adhere to (the paint peels off of the caulking). Other caulks are not good when used where they are in contact with concrete (porches, sidewalks, driveways) and fail if water pools while in contact with the caulking.

Cement Board – We use cement boards instead of plywood when repairing EIFS stucco walls. A layer of tar paper is placed behind the cement board to prevent any water seepage into the wall. The cement board is usually 0.5” thick, is attached to the wall studs with either nails or screws, and is compatible with the stucco basecoat and stucco textures that we use. If water does come in contact with the cement board, it is very porous and will not retain water very long, compared to any wood product which warps and deteriorates when exposed to water for long periods of time.

Conventional Stucco – When a solid layer of concrete is applied onto a wall, we call this conventional stucco. This differs from EIFS stucco, which has a Styrofoam base instead of cement. Most conventional stucco applications include a vapor barrier behind the stucco, metal lath attached through the vapor barrier and into the wall framing, 2 layers of cement coating, and then a textured finish layer which can be painted.

Cracks – There are many different types of cracks that occur in stucco. Settlement related cracks usually occur at the floor lines and are primarily horizontal. Shear cracks are found at the corners of doorways and windows and are caused by side-to-side movement of the building usually from winds. Eggshell cracking occurs in conventional stucco resembling the thin cracks in an egg shell and is normal. Finally, straight-line cracks are usually the result of improper installation of the stucco or the wall on which the stucco is attached on to and are most often vertical. Cracks can be repaired, but can return if the problem that is causing the crack is not corrected as well. Sometimes, repairing the underlying condition costs more than most customers are willing to spend.

Cut Above – In most areas, building codes require the stucco to terminate above the grade (soil level), especially if the area has subterranean termites. To remove the stucco that is in contact with the soil and seal off the bottom edge of the stucco is called a “cut above.” Most termite companies require that the average distance from the stucco down to the grade is at least 6”.

Damaged Framing – The wall framing that the stucco is attached to can become rotted due to excess moisture and/or damaged by wood eating organisms (ants, termites, and mold). Replacing damaged framing can cause damage to the inside finish because the drywall is attached to the same wood that needs to be replaced from the outside.

Delamination – There are two types of delamination (separation from the wall) that occur to stucco. When the top layer of stucco texture delaminates, only the thin textured coating separates from the cement layer that it was applied on to. This occurs when too much moisture is present behind the texture layer, or if either the textured and/or cement layer froze during the initial application, preventing a good adhesion of the materials. The second type of delamination usually occurs in EIFS stucco when the underlying foam board separates from the substrate that it is attached on to, resulting in a bubble in the entire wall area. This is caused when the house settles (a vertical shift of the wall) and the adhesive material that holds the foam onto the wall fails, usually due to improper initial installation.

Drip Edge (Flashing) – This is a specific type of flashing added over the top of doors and windows to force water that drains down a wall surface, away from the molding that surrounds these wall penetrations. Our experience has shown us that most window and door installations did not have this piece of flashing added when they were installed.

Efflorescence – When excessive moisture finds its way under a stucco surface, the salts in the stucco and/or the mortar in a cement wall application can leach out and appear as a white powdery coating on the wall surface. This cosmetic condition can easily be removed after the source of the water has been repaired.

EIFS Stucco – EIFS is an acronym for Exterior Insulation Finish System. This type of stucco includes a Styrofoam base with a thin layer of cement coating on which a layer of texture coating is applied. Another component is a fiberglass mesh that is embedded into the cement layer for additional strength. The thickness of the fiberglass mesh determines how resilient the entire surface is to impact damage. Dry-vit^® is a manufacturer of EIFS stucco and has become the name brand associated with EIFS, in spite of the fact that during the early 1990’s there were over 25 manufacturers of EIFS products in the US.

Elastomeric Paint – This type of paint differs from acrylic paint in that it has the ability to stretch as much as 1/8” when the underlying surface moves and is most often used on conventional stucco surfaces. The biggest problem with this type of paint is that it is also a complete vapor barrier, which does not allow moisture to evaporate from behind the paint when a penetration fails (window opening, vent, etc.). Master Stucco uses this type of paint to seal horizontal surfaces, for example the tops of walls and chimneys where water can migrate vertically through the surface into the wall and cause damage.

Erosion – Over time, rain washes off the thin coating of texture, exposing the embedded aggregate which eventually falls off. Master Stucco has mastered the art of blending in new texture to replace the eroded areas without having to coat the entire wall surface.

Expansion (Control) Joints – All buildings move throughout the year. Some movement is side-to-side and other movement is vertical. Expansion joints force the movement to occur at an intentional weak point in the wall:  a line that is placed in the stucco which is filled with caulking to absorb the movement.

Fascia Board – This is a piece of wood on the upper roofline of a home on which the gutters are normally attached.

Fiberboard Stucco – Some contractors used this masonry board that has an imitation stucco texture on the surface instead of using real stucco. This type of material is very susceptible to moisture problems and deteriorates easily when exposed to moisture.

Finish Coat – This name is refers to the final texture coat applied onto the cement surface.

Flashing – There are many different types of flashing used in stucco, but the most frequent include: kick out (diverter) flashing, step flashing, cap flashing, drip flashing, and deck flashing. Kick out flashing is inserted at the intersection of lower rooflines with taller vertical walls. Step flashing is metal flashing installed under the shingles where the shingles intersect with the taller wall. Cap flashing is placed on top of a wall that rises above the roof to prevent moisture intrusion.  Drip flashing is placed on top of window and door openings to prevent water from entering behind the wall at the top of the opening. Finally, deck flashing prevents water from entering into the wall where the deck intersects with the vertical wall.

Frieze Board – This vertical piece of wood is located below the soffit (horizontal wood under the roof overhang) at the top of walls.

Gyprock^® – This material is used in most EIFS applications and is attached to the studs on the outside of the home. It is very similar to drywall, inexpensive, and compatible with the cement adhesive used in applying the foam layer of EIFS stucco. When doing repairs, this material completely breaks into pieces and has to be replaced.

Impact Damage – Damage that results from any object hitting the stucco surface.

Lath – A metal or fiberglass mesh used in conventional stucco to increase the strength of the concrete layer. Without lath, the stucco will be thinner and the wall will be more susceptible to cracking.

Mildew vs. Mold – Mildew is a green fungus that grows in exterior areas that do not have regular sunshine, usually on the North-facing walls. Alternatively, mold grows on the inside of walls where high moisture conditions are present.

OSB – OSB is an acronym for Oriented Strand Board, and is an inexpensive engineered plywood made from glued together wafers of wood.

Rusting – The types of rusting that affects stucco is when the aggregate (sand) contains small pieces of iron ore which become exposed to the elements as a result of surface erosion. This is a cosmetic condition and looks like upside down tear drops with a small rust spot at the top.

Scratch Coat – When applying the cement layer of stucco on a conventional stucco project, the first coat of cement is called the scratch coat. While the cement is still wet, the applicator “scratches” the surface so that when the second coat of cement (brown coat) is applied, it can better adhere to the scratch coat.

Settlement Damage – When a new house is built, it usually has “green” wood, which is not completely dried when installed. As the house increases in weight (adding drywall, flooring, etc.), and the wood dries, the wall will shift down in a vertical direction, compressing the stucco as it “settles.” Settlement damage is usually visible at the floor lines where the majority of the movement takes place and includes buckles, ripples, and cracks of the stucco surface.

Soffit – Horizontal piece of wood under the roof overhang.

Stucco Above Shingles – When a stucco wall rises above the shingles (gables, chimneys, dormers, and taller upper floors), the stucco is often placed in direct contact with the shingles where they meet the taller wall. When a new roof is installed, the existing step flashing (metal flashing installed under the shingles where the shingles intersect with the taller wall) is interlaced with the shingles (flashing, shingle, flashing, shingle) and does not line up with the placement of the new shingles. To fix this the roofing company requires the stucco to be cut to insert the replacement flashing up against the wall with the new shingles. When this happens, Master Stucco replaces the stucco in the affected area, but leaves a 2” space under the repaired stucco so that the next time the shingles have to be replaced, the roofing company can do their job without damaging the stucco.

Substrate – This is the material on which the stucco is attached to. It can be a concrete block wall, or a wood framed wall with a layer of plywood, OSB (wafer board), or Gyprock^® (exterior drywall).

Texture Differences – When the final textured surface is applied, the thickness of the sand, and the manner in which it is applied affect the aesthetic appearance of the texture. When repairing this surface, the repairman must use a material that contains similar sized aggregate (sand) and apply it in the same manner that the original texture was applied to create a seamless repair. Painting a textured surface alters the depth of the pores of the surface and also affects the final repair of affected area. Master Stucco has developed repair methods that blend in the new texture with the existing for a seamless repair.

Vapor Barrier – A layer of material that is moisture resistant and used to prevent moisture from migrating into an underlying wall surface or cavity. Usually this would be black tar paper or a house wrap material like Tyvek^®.

Window Molding Pieces – Most windows have decorative trim moldings added on the outside of the window and include brick molding, sill nose, and mullions. Brick molding is usually found on the sides and top of a window and/or door.  Sill nose molding is attached to the front of the window sill.  Mullions are a horizontal and/or vertical piece of wood between two windows – usually an upper and lower window group.

Window Sash – Moving window that includes a wood frame and pieces of framed glass.

Window Sill – The bottom piece of a window frame. Nails are placed up through the bottom of the sill into vertical sides to hold the window together. The sill is affected by moisture that gets trapped behind the tracks that the sash slides up and down in. Master Stucco has mastered the replacement of window sills without having to replace the entire window group. This saves a lot of money when one window is damaged, but that design is no longer available for purchase.

Woodpecker Holes – These round holes are usually found at the top of a chimney or tall wall on EIFS homes. Woodpeckers make these holes for access to create a nest. Master Stucco has developed preventative repairs that we guarantee to prevent future damage from woodpeckers.