Ask The Expert
We may have messed up here at our HOA. One of our board members hired a contractor and did not check his license or references or anything. I think it’s going to bite us where we don’t like things biting us. He was hired for a waterproofing issue in Santa Clarita. He dug out about half of a very large planter, but he did not get any permits. He waterproofed the front of the wall and four feet on the bottom of the planter and told us that the water would not come into the building, but water is coming inside the building. He is not returning our calls, and it gets worse: The address on his business card is to a storage unit. I personally saw the material that he waterproofed the planter with. It was a black rubber and green Styrofoam. How could this leak? What do we do? Thank you for your time,
The green Styrofoam is called Amacore board, which is used to protect the waterproofing membrane from rocks during the backfill. The black rubber material you are describing could be bituthene, which is a good waterproofing agent, but it could also be roofing tar.
The reason it’s still leaking is because he only sealed half of the planter either to save money or time or perhaps just a lack of experience. Because concrete is porous, water will leach through the non-waterproofed section, travel under the waterproofing, and then into the building.
At this point, unfortunately, the entire planter will have to be excavated and all of the waterproofing he applied must be removed. If he did use roofing mastic it will eventually crack and give you leaks. It will have to be removed by sandblasting.
My recommendation for not only this repair but any future work is to go with a reputable contractor. Check with friends, check references, check with the Contractor’s State License Board. Don’t just hire anybody off of the street. You want to make sure they are licensed and have Worker’s Comp.
The City of Santa Clarita will not require you to pull permits for waterproofing or sandblasting. Personally, I wish this was not the case, but that’s the way it is. Beverly Hills, however, and zones 1 and 2 of Los Angeles do require permits for waterproofing. I, for one, appreciate the Building Department being involved.
Your planter may also need crickets, which will act to raise the water and channel it over to a drain. If you have subterranean parking and you don’t have drains, then spend the extra money and install them. You would first need to X-ray the slab to make sure not to core through rebar or post tension cables. If the slab is more than 10” they would have to go to a cobalt x-ray.
The bottom line is doing it right the first time is always better. In this case, you’ve spent bad money on this problem and were misguided by someone who does not know what they were doing. Now, you need to spend good money to have the work redone the right way.