Welcome to Renovators

The dictionary defines “stucco” as plaster or cement for surfacing walls. Stucco is an old-fashioned yet low-cost, aesthetically pleasing, durable cladding. We use products which combine the best of engineered fiber reinforced cement stucco with technologically advanced elastomeric finishes to create a stucco-type system that provides a superior cladding over traditional, field mixed sand, lime and cement. Superior products in a superior system create a more durable and colorfast exterior wall cladding. These products are designed for maximum effective crack bridging which does not allow moisture to get in the wall.

Achieving Lasting Performance and Durability in Stucco Systems

Understanding appropriate construction practices and some of the common causes of problems in exterior stucco can help prevent future problems. Building construction should comply with National, State and Local Building Codes. Less than complete code compliance seriously jeopardizes an owner's or builder's investment. Construction details, particularly flashing at window sills, roof/wall intersections, decks and other transition areas of construction should be designed or built to divert water to the exterior, not into the walls.

Cracking to some degree is normal in stucco. Understanding the numerous factors that contribute to cracking, including the following conditions, can encourage construction and maintenance practice that minimize cracking:

Stucco at and below grade can cause problems with durability that require continual maintenance. Sound grading and landscaping practices should be used to provide effective drainage of water away from the walls of the structure at grade, and the stucco should be kept well above finished grade. Wood framing or sheathing should never go below grade.

Sprinklers should not use walls as a means of diverting water to gardens or lawns. Drip irrigation should not keep soil continually wet near base of wall.

Horizontal and low-slope surfaces are not intended for stucco applications. Extra surface preparation is required and periodic maintenance and reduced durability should be expected for any weather-exposed sloped surfaces.

Retaining walls and planters should be thoroughly waterproofed from the inside (where the soil makes contact) before putting any stucco on the outside.

Caulking should be installed at all terminations of the stucco and all openings through the stucco (windows, doors, pipes, vent, etc.).

Scuppers or canals should not use the walls to drain water from the roof into or onto walls.

Choice of color can be a determining factor in the longevity of the stucco's like new appearance. Dark colors will generally fade faster than lighter colors and require more frequent maintenance, including recoating.

The first step is the proper installation of moisture barriers (please visit our section on StoGuard™) and appropriate accessories at stucco terminations and joints. A galvanized steel diamond mesh metal lath is fastened to the framing or substrate. At this point, kick-out flashing or diverters need to be installed at lower roof terminations.

We then apply Sto® Powerwall Stucco which is a pre-mixed and pre-measured cement, lime, fibers and additives formula which has much more consistent quality control than on the job, field mixed stucco. Two layers of stucco are applied: the first, a “scratch” layer which is horizontally scratched so that the second coat adheres to it, followed by a “brown coat” which is leveled to achieve a smooth, plumb surface.

This step is very important, however, most stucco contractors will prepare their own blend of Portland cement, lime, sand, and—hopefully—fibers and additives. But what happens if they run out of, let’s say, fibers, right in the middle of mixing a batch? You guessed it: that batch will not contain fibers! And these fibers, as insignificant as they sound, are the ones that provide additional tensile strength and minimize hairline cracks. You can only speculate on how accurate the ratio of components will be.

Ideally, stucco should be allowed to cure for 28 days. When this is not possible, we do have additives to accelerate the curing process, reducing it to seven days.

An acrylic-based primer is applied, which is vapor permeable, allowing the substrate to breath naturally and improving water resistance, reducing chance of efflorescence. This primer is tinted to the same color as the finish, improving color uniformity.

A textured, color-integrated finish is the final shell. Sto® manufacturers three (good, better, best) coating systems with warranties ranging from 5 to 10 years.

Finally, an optimum grade sealant or caulking (we use DC-795 and NP1) needs to be properly applied to all openings, utility penetration, electrical fixtures, and all other areas where stucco meets dissimilar surfaces.

Trim Bands, Keystones and Quoins

Door and window openings can be enhanced with decorative trim bands, columns, sills, keystones, and quoins. A different texture and/or contrasting colors may be used.

Moisture management is a top priority in a stucco system because water is one of the major culprits in plaster deterioration. It can lead to rust and rot. It enters the building through cracks, through the roof, around chimneys, or through window and door openings. It can get behind building paper that is torn or not properly lapped at seams.

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 applicator.

Finding the Problem Behind the Problem

Visible signs of deterioration may be exhibited in the form of cracks, spalls, delamination of the stucco coating, efflorescence (a type of white chalking) flaking, or peeling of the stucco itself. Our objective is to find the cause of the damage, correct it (i.e., install kick-out diverters, flashing, sealants) and then repair as required, blending in the finished product to the existing texture and color.

Notice that we use the term “blend” as the texture is hand-made and thus unique—like a fingerprint—to the applicator. The color matches are very close, however, stucco samples are tri-dimensional due to the texture, hence color scanners used for matching will not read these with total precision, plus the weathering factor affecting the existing finish.

Above Grade Horizontal Cut

Also referred to as a termite cut. Synthetic (i.e., EIFS, Duravit) stucco walls should be terminated at least 4” above earth grade, 2” above finished (pavers/sidewalk/slab) grade. Older construction practices sometimes overlooked this procedure and the synthetic stucco—a foam board covered by a textured finish—was applied down to the foundation, below grade.

At least a couple of situations arise from this: moisture intrusion from the ground up starts the wood rotting process, and b), the foam board is a perfect shield for the termites to travel up to the wood unobstructed. Most exterminating companies require this clearance for visual detection of termite migration.

The “termite cut” process includes cutting and removing the foam board below grade and a minimum of 4” above, embedding a fiberglass mesh in Sto® Watertight Coat which is a flexible and breathable waterproofing membrane based on a unique combination of acrylic emulsion, Portland cement and fine fibers. It is used to waterproof all types of above or be-low grade concrete. A textured finish is then applied to blend in with existing appearance.

Hardcoat stucco applications usually do not require this horizontal cut unless there is water penetration and possible wood damage behind the stucco cladding. In such case, the stucco needs to be removed to expose damage and allow for correction. All below grade surface will be layered with cement board (Durock) and skimmed with Sto® Watertight Coat—a waterproofing membrane. A textured finish is then applied to blend in with existing appearance.