IN THE MAIL: More letters on the problem of paint adhesion to the lower part of stucco walls (Dear Dale, April 14, May 5):
Lee Koelfgen Jr. of Rainguard Products Co., 821 W. Hyde Park Blvd., Inglewood, writes that paint failure at the lower part of a stucco wall can be solved by the suggestions in the May 5 column only if the failure is caused by rainfall or sprinklers.
"Unfortunately, neither of your readers (responding in the May 5 column) has considered a third cause. Most California homes exhibiting this problem have stucco extending below ground level. Stucco will absorb moisture from the ground and 'wick' it upward. This moisture will either deteriorate the stucco underlying the patched and waterproofed areas (eventually causing a failure of the repair) or it will (on a south or west exposure) have enough vapor pressure buildup due to sunlight to 'blow' an impervious coating off the wall.
"The ultimate solution, of course, is to waterproof stucco below grade with an impervious material to prevent wicking. The lazy man's way is to saw cut the stucco slightly above grade (a kerf cut through the stucco to the concrete footing) and fill this kerf with a waterproof caulking that interrupts the wicking. A subsequent waterproofing application above this saw cut can then be totally effective."
Koelfgen adds that his firm neither manufactures nor distributes below-grade waterproofing materials.
In a similar vein, Paul H. Dehne of Templeton, Calif., suggests that to solve the paint adhesion problem you should "use an electric angle drill with a carborundum disk to cut through the stucco about three inches above the soil line, parallel to the ground. Cut this groove into the stucco up the concrete foundation. Fill this groove with a waterproof cauling by using a caulking gun. This will act as a barrier to any moisture coming up from the soil."
Sounds like Paul and Lee are on the same wavelength! Paul suggests using a board on the ground next to the foundation to serve as a rest for the drill while you are cutting the groove. "Needless to say, wearing safety goggles is a must," he says. Amen to that! After the caulking is in, proceed to clean the damaged stucco and repaint.
Dale Baldwin will answer remodeling questions of general interest on this page. Send your questions to Home Improvement, Real Estate Department, Los Angeles Times, Times Mirror Square, Los Angeles 90053. Baldwin cannot answer questions individually. Snapshots of successful do-it-yourself projects may be submitted but cannot be returned.