I hired Abarent Construction Ltd. (Edmonton) to excavate approximately half of my home’s foundation and install weeping tile at the level of the foundation footing, install a waterproofing membrane and insulation on the outside wall of the part of the house that had been excavated, install a new sump and pump in the basement and connect the weeping tile into the sump. This review is written for the benefit of anyone considering having this type of work done (by this or any contractor) to help avoid the issues that I experienced. If you are considering getting this type of work done on your home and you don’t have the time or patience to read this entire lengthy review, do yourself a favour and at least read Recommendation 4 at the bottom of this review. I also provide a conditional recommendation for this contractor at the bottom of this review.
The quote that I received from Abarent Construction was thorough, logical, professional, and detailed. I am an engineer and the quote was prepared the way that I would do it including provision of drawings of how the installation will be completed and details of what components were included. Abarent far exceeded the other contractors that I got quotes from, in this regard. I received quotes from three contractors and the quote from Abarent Construction was in the middle in terms of pricing. I decided to go with Abarent because of the professionalism during the quote and proposal review process, better availability of this contractor over the low bidder, and because I believed that the product that they used for exterior wall waterproofing was superior in performance to the products used by their competition.
This company is very organized and efficient. I had made a couple of special requests to the owner at the time of accepting his proposal and this information had been conveyed to the project coordinator and in turn to the crews doing the work. Every morning that work is being done, the project coordinator will contact you and explain what work is going to happen at the house that day. I was around for most of the work and I could see that it was done very efficiently. I had requested that the crews take extra care not to damage my recently installed acrylic stucco and for the most part, they were very careful and I experienced only a small amount of accidental damage which I consider good, considering the nature of this work.
I did experience an issue with the waterproofing membrane that was applied to the exterior wall of my house. At the time that my project was completed it was cold (low single digit Celsius) and it rained off and on during the week. As a result, the waterproofing membrane product went on thicker than usual and that compounded the fact that any product will take longer to cure when the air is cold with high relative humidity, as was the case for my project. I had been warned by both the owner and the project coordinator that there would be a strong solvent smell during the application and curing of the membrane but they both assured me that it was not harmful. Because of that and because I assumed that any smell would be quite temporary and not too far different in intensity or duration to other products that I have experienced using, I did not think too much of it at the time of being told that. The project coordinator had advised me to keep all of my doors and windows closed when the membrane was being applied to reduce the solvent smell inside the house but the workers themselves left the back door open while they ran up and down the stairs completing the sump. As a result, I did get some significant amount of solvent smell in the house on the day of application that was quite bothersome. But the real problem occurred later after the house was backfilled by the crew. The membrane was evidently not fully cured and with the walls backfilled and no longer open to atmosphere, the off gassing solvent went directly into the weeping tile, which is connected to the sump. The sump has a lid but it was not sealed and the workers had cut off a corner of the lid for the pump’s power cords to fit through. Most houses operate at a slight negative air pressure, so even this small amount of opening was enough to fill my house with a very strong smell of solvent, particularly so in the basement where I live due to upstairs renovations in progress. I opened windows and implemented various mechanical (fans) and natural ventilation methods to remove the solvent smell but this didn’t stop the root cause of off gassing solvent fumes entering the sump. I eventually needed to seal the sump lid with caulking before the problem went away completely.
The problem that I experienced with strong solvent fumes in my home was entirely avoidable with a few simple preventive measures. So homeowners - here are my recommendations to you and this advice might apply to work done by any contractor:
1) Contractors may say that the products they use are harmless but I suggest that you read the product Technical Data Sheet and the Material Safety Data Sheet (MSDS). The product used by this company (Bakor Aquabloc 770-06) is made by Henry Company and you can access these documents either from the company’s website or by contacting them directly. If the product contains chemicals that you think would not be good to have in your body, then have a ventilation plan and ventilate immediately if you smell solvents or chemicals in your home (you are unlikely to be able to avoid all ingress into the house but if the preventive measures below are followed, they should be minimal and able to be addressed by ventilation).
2) Ask your contractor to apply the waterproofing product(s) after the sump is finished so they won’t need to leave your door open (transporting materials out of or into the house) while the products are being applied. During and after the product is applied, keep your outside doors and windows closed, only opening when necessary. You should also consider plugging your air intakes and vents and if seasonally practical, turning your furnace/AC off to reduce ingress of gases from the curing products.
3) Ensure that the contractor follows the manufacturer’s instructions for application of the product(s). The manufacturer of the Bakor Aquabloc product recommends that the product be conditioned to room temperature and (trowel, squeegee or spray) applied at a thickness of 90 mil (0.090 inch). Product applied at a higher thickness will take longer to cure, and off gas more solvent, all other things being equal.
4) It may be difficult or impractical to control or monitor the contractor’s methods on the previous two points, but here is the most critical preventive measure that you can control – ENSURE THAT THE CONTRACTOR THOROUGHLY SEALS THE SUMP LID!!! Make this a written condition of accepting the contract and if it doesn’t get done, do it yourself. Ideally this would be done before the waterproofing product(s) is applied to your wall but based on my experience, it is at least imperative that it be done before the backfill occurs. By far the highest amount of solvent fumes that got into my home did so after the house was backfilled and at this point, the path of entry was very clearly through the weeping tile into the sump. I sealed my sump by purchasing another lid, carefully notching it out to leave just enough room for the pump power cords and thoroughly caulking the lid and cords. Doing this completely solved the problem. This method, while very effective, will make it more difficult for me to access the sump in the future. Instead, a very simple and economical way that a seal can be made is to apply two rings of good quality caulking (maybe an inch or so apart) to the cement around the outside perimeter of the sump opening. Apply the caulking thick around the power cords and embed them fully into the caulking. Then cut a square of 6mil clear polyethylene sheet larger than the caulking rings and lay it over the sump and press it down into the caulking to effect a (double) seal. (I would also remove the supplied sump lid so you can see inside the sump and make sure your pump is working). This is likely about a 10 minute job when done by an experienced person – so your contractor should have no objection to doing this for you. If only this one step had been implemented at my home as soon as the sump was finished, it would have prevented most or all of the solvent fumes in my home after the backfill.
CONDITIONAL RECOMMENDATION – I believe Abarent Construction uses the product that they do because they believe it to be the most effective product to waterproof your wall and allows them to stand behind their excellent warranty on this work. Indeed, this was one of the reasons that I chose this contractor. So if the above steps 2-4 would be implemented by this contractor on future projects, then I would be prepared to recommend this contractor for this type of work as I think that they did everything else well.