CONTRIBUTORS | CONCRETE
Is Your Foundation a Safety Liability?
DAMIEN ENRIGHT
Storm season means it’s time for a stability check of the potentially shifting soils around your building
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t’s storm season again, and you know the drill: secure your roof, stormproof your windows, sample your soil. Sample your soil? Yes, foundations fall victim to storms. And in a big way. Sinking, landslides, failing seawalls all could be your problem with heavy rain. Not to mention a hurricane. The high volume of water and improper drainage can lead to fatal shifting of your building’s base and wreak havoc on the structure of a building. And you don’t necessarily feel your building’s groundwork moving, or hear any cracking. So how can you tell if your building’s foundation is compromised or unstable? There are definite symptoms you can look for to determine if your building is sinking. Cracks in drywall, crevices or voids in outside walls, windows or doors sticking when being opened or closed are all telling you the foundation is no longer level and may require realignment to avoid further damage. If your building is nestled against a hillside, you may even need to excavate the soil that’s bodied up to the edifice to expose the wall and look for fractures. So you’ve suddenly noticed a sinister crack creeping up a wall. Now what? You’ll need to figure out what’s happening beneath the symptoms to know the truth of the underlying issues. That’s where a soil sample comes in. A soil analysis will indicate exactly what’s wrong and the best solution to treat your certain type of soil. You see, Hawaii has some of trickiest soils in the United States. Oahu alone has a dozen different soils, including sand, corals, boulders, gravels, swamp and
expansive clays. The type of soil your foundation is built on will determine what treatment is required. Therefore, a professional must take samples of all the different layers of soil at your property to learn the density, solidity and moisture content. The engineer should also conduct an indoor topographic map of your flooring to see how level—or not so level—your building is. Once they determine your exact soil type and the location of the settlement, you can take action with a proper engineered solution. Your treatment might be to apply a thick coat of waterproofing on the wall. If your building is next to a hillside, you may have the option to inject polyurethane foam as a gel barrier by drilling through the lower room, to avoid having to excavate the soil and save on costs. You may need support piles installed to the sinking side of your building in order to lift it out of the sliding soil. A good foundation stabilization expert will have different piles for different soils. Your engineer report will determine where the basalt is and then they will use the appropriate pile(s) to elevate your building’s weight off of the soft, shifting soil and lock it down into hard, unmoving bedrock, re-leveling it as much as 12 inches. When you’re ready to call a foundation specialist, check the DDCA to see if the contractor has the proper licenses (and has been licensed for a while) for the treatments necessary to restore your foundation. Your project may necessitate many licenses, depending on what the engineer recommends, including waterproofing, excavation, concrete construction and/or pile-driving licenses. Checking
24 BUILDING MANAGEMENT HAWAII | JULY 2020
for licenses will help you avoid hiring a contractor who’s trying to expand to project types in which they aren’t necessarily experts, and ultimately could save you from unnecessary problems and labor costs. You should also take out a $5- to
