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Spring Maintenance – Water Issues and Humidity in the Home

I live in eastern Ontario and the sump pump in my house runs about every 20 minutes. I have installed a battery backup system and would like to know what other preventative measures I can take to reduce the amount of time the sump pump runs. – Doug, Ingleside, ON

Hey, Doug. There are a few possibilities I can think of — the most likely being a high water table in your area or a float that needs adjustment. The battery backup system is a great idea but your pump has a lifespan and the battery system won’t help if your pump quits.

An easy way to check the water table is to shut off the pump on a dry day and monitor the water level to see where it stabilizes. If the pit fills to within a few inches or less of the bottom of your basement slab, you’ll want to have a waterproofing contractor come in to investigate and come up with some solutions that could range anywhere from another weeping tile, to an exterior pumping and cistern system to take the hydrostatic pressure off your foundation. If there’s plenty of wiggle room between the bottom of your basement slab and the top of the water in your pit, a simple adjustment of the float on your pump should do the trick.

I live north of Toronto in sandy soil, in the woods on a slight hill — drainage is not a problem. My garage floor is concrete and gets terribly wet when it’s humid. I have painted it with what the hardware store said was a waterproofing agent. But, as it dries, it becomes powdery and when I sweep it just seems to come off as a powder. Do you know a product that would work? I don’t like having wet feet when walking into the house. – Diane W., Whitchurch-Stouffville, Ont.

Well Diane, we’ve had a summer where we’ve had warm, humid weather followed by cold snaps. I’m wondering if you leave your garage door open all the time? That slab of concrete will actually heat up and cool down slower than the air around it, since it has much more thermal mass — if the concrete is cool in the morning because it’s been a cold night, and then it becomes a very hot day, the humidity will actually condense on top of that concrete. So it’s not necessarily coming out of the ground — it could be coming out of the air. The only good way to really avoid that is to keep your garage door closed, which limits the amount of humid air getting in there. Another way would be to have a dehumidifier running .

I’m a little baffled by the waterproofing agent that’s becoming powdery and dry. Usually, waterproofing for a concrete floor would come in the form of an epoxy garage-finishing and sealing system, or a penetrating sealer you would use on natural stone and tile. Of course, that would not stop a condensation problem, but simply stop water from penetrating. If it’s becoming powdery, I’m wondering if maybe there is excess moisture beneath that slab and what you’re seeing is efflorescence — the salts and other minerals that are in the concrete, which come up in a powdery form when the slab dries out. If that’s the case, the penetrating sealer is the way to go.