Question: Robert, I am the president of an older homeowners association here in Santa Clarita, where we have underground parking. The walls have been leaking for years, this being the worst yet, so we’ve begun looking into waterproofing. We’ve been told about both positive and negative waterproofing, and are astounded at the cost of the positive waterproofing – it’s astronomical.
We’ve got four buildings total and they all need this repair, so unless we do a special assessment there is no way the association can afford this costly procedure. We do understand, though, that the positive waterproofing option is the best and is a once-and-done process.
There is a third we’ve heard about though have been told it’s less effective: It’s the injection method. Would you please elaborate on these procedures, and weigh in for us?
Thank you for any insight you can give. We’d like to make the most economical choice for the long term, but need all of the facts first. Your column has been invaluable over the years. Our board of directors has referred to your advice on many maintenance and repair issues and we all value your opinion.
— Bill
Answer: Bill, let’s begin with information on the injection process: In my opinion this is a total and complete waste of financial resources and I do not recommend it. The theory — that the liquid injected between the soil and the concrete or block will seal the area and prevent water from penetrating — is clearly not effective. I’ve seen it fail time and time again, and of course, funds therefore be wasted.
Positive waterproofing is by far the best option and, done correctly, your guaranteed fix for a situation like yours.
Cost? Yes, astronomical, because of the intense labor involved. Everything from hardscape to softscape needs to be dug out around the building, in its entirety, so that the wall, in whatever materials it is made from, is completely exposed by 3 feet. You cannot just dig down 3 feet and work safely with that exposed soil — this all has to be shored up for safety, to prevent collapse.
This is all intense man hours of labor, whether it is machine or hand dug. In some areas it will be hand digging only, due to water/power lines in the area. Multiply all of this by four buildings and add in the ridiculous cost of products today, and you are absolutely looking at the “national debt,” in total costs.
Lastly, there is the negative waterproofing option. This is the faster fix for immediate relief. However, we guarantee nothing with this process because it is only a matter of time before it fails. It will absolutely buy you some time, but it is not a fix, it is just a Band-Aid.
Imagine a wound with a Band-Aid, and you go swimming. Eventually that
Band-Aid will be soaked enough where it will fail and fall off. This is the same with the negative waterproofing process.
If your association is in a healthy financial state, it may be wise to tackle one building at a time over the years, with positive waterproofing. The problem with not addressing this at some point is all of the water that continues to leach into the concrete/block eventually causes rust of the steel within. When this happens it expands and begins to create spalling, which is the crumbling of the concrete/block, little by little. This is a failure of the integrity of the walls and eventually will become an engineering issue, and a building could be deemed unsafe.
I’ve seen this in my many years of experience and I’ve seen it break associations. If there is any way possible that your association could tend to this with positive waterproofing, I highly recommend figuring that out. Best of luck to you.
Robert Lamoureux has more than 40 years of experience as a general contractor, with separate licenses in electrical and plumbing contracting. He owns IMS Construction Inc. in Valencia. His opinions are his own, not necessarily those of The Signal. Opinions expressed in this column are not meant to replace the recommendations of a qualified contractor after that contractor has made a thorough visual inspection. Email questions to Robert at [email protected].
