Question: We purchased a new apartment building a year ago. The apartments are above a subterranean garage that extends under the entire apartment structure. The first floor slab (subterranean garage ceiling) is exposed to weather as it is not enclosed with a roof. We are trying to decide on a product that will provide us with good waterproofing to elminate water dripping on vehicles when it rains as well as aproduct that will be low maintenance. What do you suggest?
Answer: Walter F. Pruter of W. F. Pruter Associates, 3127 Los Feliz Blvd., a construction technical consultant, handled this one for me. I put him in touch with the reader and he will send her full details.
First of all, weather-exposed surfaces must be constructed to make water drain away from the building, he said. In your case, he said to make sure that exposed deck and/or porch slabs slope away from the exterior walls.
Assuming the deck-ceiling slab is cast-in-place concrete poured dead level, or--worse--sloping towards the building, Pruter recommends that proper drainage be achieved by placing a new fill on top of the old slab.