Q: In 2005, we painted our 1959 stucco house in the Washington Manor area of San Leandro, Calif., with elastomeric paint. Over the course of the week, I watched the contractor power-wash, scrape, then prime and roll on the new paint.
Within six months, the new paint began to peel and flake. The contractor came back and redid the work, but it continues to flake off. I want to repaint my house without elastomeric paint. How do I seal the walls?
A: Generally, elastomeric paint, a thick, durable product that expands and contracts with the weather, is good stuff. We did a little digging and found a sprinkling of references to some problems with the application of elastomeric paint.
It sounds to us like your painting contractor did a good job following all the right steps. We confess we’re befuddled as to why the previous job failed. One answer might well be incompatibility of materials. But another might be continuing moisture penetration behind the stucco itself. Stucco and paint are engineered to "breathe," allowing some moisture to escape. But constant dampness is never good.
Do a thorough inspection of the roof and places where wood joins the stucco. These are likely areas where water can get between the stucco and the wood substrate. Our recollection is that homes in the Manor did not have weep screeds (a type of metal flashing) at the bottom of the walls to wick away moisture.
This makes it possible that excess moisture in the stucco could have contributed to the failure of the elastomeric job. So pay attention to the areas under the windows and doors and where the stucco hits ground level. That’s often where water finds its way in.
The process to repaint is essentially the same as your painting contractor followed. Pressure wash the stucco to remove dirt and whatever peeling paint may be left. Patch any cracks, being sure to take care of any area where moisture can get behind the stucco. Prime the surface and apply the finish coats. Attention to detail in each of these steps will produce a quality job.
Before pressure washing, use a shovel to lower the grade at the base of the stucco. Make sure to pressure wash the dirt off this area. This will ensure that the whole wall is primed and painted, top to bottom. Pressure wash the stucco at a pressure of between 1,200 to 1,500 pounds per square inch using a wide spray pattern to avoid damaging it.
Let the stucco dry a day or two after pressure washing. This will allow any residual moisture to evaporate. Next, prime the walls. This step will seal any small voids in the stucco body. Make sure the primer is formulated for use on stucco and that the finish material is compatible for that primer.
We suggest purchasing the primer and finish paint at a paint store, rather than a hardware store or home center. That way you can be relatively certain the primer and finish coats are compatible.
The next step is to seal any cracks. Don’t throw a rock at us, but we recommend elastomeric caulk and a brush grade elastomeric coating for this step. We really like the elasticity of this material. It greatly lessens the chance that surface cracks will reappear.
Pay special attention to areas around door and window frames, as stucco tends to crack at the joint where window and door frames meet the wall.
Finally, apply two coats of 100 percent acrylic latex paint in the color of your choice. Don’t skimp. The higher the cost, the better the paint. Follow these steps and you should have a long-lasting paint job this time around.
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