Scott Razzino has an all-too-familiar problem. The basement of his 1,100-sq.-ft. home in Atlanta is chronically damp. He’s installed a 65-pint dehumidifier, which must be emptied every day. Surely, he wonders in this Q&A post, there must be a better way to tackle the problem.
Razzino reports that the house is about 26 years old and has a block foundation. He’s routed gutters away from the house and sealed air leaks in the walls with mortar and concrete sealant. The basement doesn’t have a sump pump.
Short of installing French drains around the house, along with a sump pump, is there anything that can be done?
The first step, says Robert Hronek, is to figure out the source of the moisture. He suggests taping foil to the wall in several spots and waiting to see whether any condensation appears.
“If the water is trapped between the wall and foil, then it is coming through,” Hronek writes. “If there is condensation on the outside of the foil, then the moisture is from air leaks.”
If moisture is migrating through the block, adds Robert Riversong, sealing the surface with two coats of UGL Drylok masonry sealer “will make a major difference.”
The manufacturer claims that Drylok’s breathable film won’t trap moisture in masonry and will withstand 10 lb. of hydrostatic pressure, “greater than a wall of water 22 ft. high.”
“Drylok is the only foundation waterproofer I will use, and it’s excellent for a capillary break between footings and foundation wall on new construction,” Riversong says. “I’ve used it to seal the interior of site-built CMU composting toilet chambers (over surface-bonding cement) as well as the exterior of exposed chimney block.”
Where is the water coming from?
“Concrete-block walls in a wet and humid climate…