Plywood installation is probably the leading cause of cracks in stucco. Start hairline stucco crack repair by cleaning the wall. I see a lot of cracks on the foam trim that is used on stucco. Apply directly to masonry walls in a two coat stucco application. The finish coat about 18 inch thick is applied over the previous two coats totaling about 38 inch, so any hairline cracks are now covered. Calculate the number of bags of readymix stucco powder you need for the job. Reasons why new stucco color coats crack, more common. If there are minor cracks in your stucco, this is a project that most san francisco homeowners can tackle if they want to. Quikrete has a stucco repair product that is textured to match the surrounding stucco. Professional stucco contractors who have a lot of experience in how to fix hairline cracks in stucco remove dirt and dust from the stucco wall before they begin filling in cracks. If you are interested in installing or repairing sheetrock in your house, we recommend doing this job before you do the brown coat on your stucco or ask your contractor to do it for you, as sheetrock is one home construction or reno project that often triggers cracks in stucco.
Is awaiting application of the brown coat and finish coat. A scratcher tool is used to get the horizontal lines in the cement and a green float is used. Hairline cracks in this color coat are inevitable, but if the base coats are well cured, these surface cracks will not communicate water through the stucco. If you want to achieve a darker shade than your original stucco color, and the surface is in good shape, quality paint can probably provide the coverage you need in one coat.
Key to no cracks is the tooth in of the new to old and the slow cure of the stucco coats. Just like any surface for example, wood siding, stucco can be repainted to suit your color preferences. Portland cement stucco cracks develop for many reasons. I see a lot of cracks on the foam trim that is used on stucco houses quite often and.
As with any cementbased material, stucco must be reinforced to resist movement cracking. Is it possible to just smooth on a topcoat over the existing stucco. Fortunately, most cracks in a stucco system are hairline and present only a cosmetic concern. Whether you specify a traditional threecoat application or a one or twocoat. The scratch and brown coats are portland cement plaster, typically each. The brown coat was applied three weeks ago, when we wet the surface, we see the spider cracks. There are two fundamental types of stresses that cause stucco cracks internal and external. It is integrally colored with faderesistant pigments, and is economical with low maintenance.
Pouredinplace andor tiltup concrete optional product upgradesenhancements product benefit omegacure liquid accelerator to improve hydration, increase early strengthhardness, and allow cold weather application coverage. Stucco cracking in portland cement plaster base coats parex. Fiberglass mesh for stucco cracks, embed or on top of brown coat kirk giordano plastering inc. The first stucco coat is called a scratch coat and as its name implies. Stucco, cracking, plaster basecoat, portland plaster. The wall should be completely watertight even with no stucco in place. Fiber mesh tape before a color coat application duration. Hedberg supply does not stock all of the materials needed for stucco brown coat application. While the adage of all stucco cracks is generally true, the use of. Diamond mesh used along corners and other higher stress locations. This is a traditional three coat stucco installation not acrylic over selffurring wire mesh 2x2 wire spacing.
This stucco system consists of a scratch coat, brown coat and finish coat. Plastic or wire mesh lath, attached with nails or screws to the structural framing, is embedded into the base coat to provide stiffening for the stucco. The finish coat is applied last, creating a decorative texture on the wall surface. Below are some examples of some hairline cracks that have occurred. Some of these problems that may identify themselves as cracks in stucco are the following. Apply the scratch coat a minimum 38inch thick, and allow the scratch coat to cure suf. In summer we hose the heck out of it daily for a month. Although not all cracks are objectionable, cracks in stucco acceptable to one person might be unacceptable to another person. Merlex revised 121009 technical bulletin 107 division 9 finishes, stucco and plaster name basex type poly mermodified base coat and antifracture membrane for smoothtroweled finishes application method hand applied with embedded mesh product overview merlex basex is specifically designed for application over brown coat. Dash, slush and slurry all refer to the technique of creating a base coat. By code, builders should provide at least 48 hours of curing time after the first coat is applied and wait seven days after the second coat. Identifying various cracks in stucco the stucco guy. U stucco pvx may also be used over wood or gypsum backing and as a scratch and brown coat application for traditional stucco systems.
Elastomeric paint is a high build coating that is designed to protect masonry surfaces. Our recommended tools, greeting our ambitious and faithful subscribers, as well as fellow plasterers. For these small cracks, get a flexible, paintable, exteriorgrade caulk. Learn how to fix hairline cracks in stucco from stucco. We recommend rounding up on all approximations, to ensure you have enough material. The stucco is in fairly good condition except for some small cracks in a few places california earthquake area. Use a dash brush to cover the entire wall to a thickness of about 18 inch. For best results, let brown coat sit 48 weeks before finishing. Both aggregate textures are available in premix or tint base 100 and 200 for use with lahabra color packs. It serves as a single product for a traditional scratch and brown coat which.
In winter her in norcal, no problem with a long, slow, moist cure. Properly done stucco will not crack, we use an acrylic top coat for durability and more or less permanent color. If cracks exceed 332 it is unacceptable and should be repaired. What do you recommend to do before the 3rd finish coat is.
Stucco is by nature hard and strong, but it is relatively thin and brittle and will crack when subjected to stresses that exceed its tensile strength. U stucco rdx may also be used over wood or gypsum backing and as a scratch and brown coat application for traditional stucco systems. The typical application of cement stucco calls for layering four coats. Mix one part cement and two parts sand with sufficient water to spatter a coat. The brown coat is applied next to create an even surface for the finish coat. Lighter than three coat stucco and conventional scratch and brown coat assemblies improves workability for faster application than scratch and brown mixes codeaccepted assemblies offering. Hairline cracks are typically around a 116 of an inch wide or smaller, if the crack is bigger than that, than chances are that some other element is the culprit. Stucco calculator product calculators do it yourself. Complies with astm c 926 requirements for cement based plaster. Can be applied with a trowel or sprayer according to typical stucco. There are several different types of stucco installations. The most traditional and popular of these types is 3 coat stucco, in which stucco is applied in three coats over metal reinforcement. The scratch coat, applied by trowel, has been applied.
Apply a dash, slush or slurry coat to the concrete wall. Its embedded in metal lath, which strengthens and secures the coat. Cracks are a common and accepted occurrence in stucco assemblies but by utilizing parex usa stucco level coat with embedded mesh over the stucco base provides enhanced crack resistance to the wall. Brown coat stucco concentrate with fibers is a portland cement based, fiber reinforced onestep base coat for stucco. Hard float the brown coat to densify plaster membrane. The scratch can be applied with a hawk and trowel, or sprayed on. Sakrete offers a stucco mix for scratch, brown, and finish coat applications. Read the instructions on the bags of stucco to determine how much a bag will cover. The brown coat in the stucco process is applied over the scratch coat mostly but can also be applied over cement based substrates as well, like the scratch coat. Mix 1 part portland cement, 1 to 2 parts of masonry sand and enough water to create a runny consistency. When the wall is pressurewashed beforehand, it will have a clean surface that paint adheres to easily.
We would like to have someone refinish the stucco by adding a smooth top coat to the existing stucco with a color added. Quikrete 80lb premixed base coat stucco mix in the stucco. Get the sheetrock installed before you put on the 2nd stucco coat. The scratch coat is applied first to provide a strong base for the system. Internal stresses are due to the natural curing and drying process of stucco. Reasons why new stucco color coats crack, more common sense. Before the finish coat is applied, bmi 690 needs to be cured for a minimum of 7 days per ubc code 2508. Sakrete also offers base coat stucco and fibered stucco. Scratch and brown coat in a three coat stucco application. Merlex basex should be mixed with clean water to the consistency of exterior portland cement brown coat. These coatings help protect your stucco from wind driven rain, and can. One method often used to help conceal the smaller surface cracks. This can be accomplished one bag at a time in a bucket with a suitable drill and mixing paddle, or in a mechanical mixer.
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