‘I don’t need foundation waterproofing services. My home is built on slab.’ Many homeowners who have slab on grade foundations share this sentiment. However, every foundation can leak and every foundation needs waterproofing. This also includes slab on grade foundations.

What happens when you have a slab on grade foundation?

Slab foundations were once preferred only for commercial buildings. However, they are becoming more popular for residential construction applications too. Short foundation walls i.e. stem walls or frost walls are built on the poured footings. Soil and gravel are used to fill the middle before a vapor barrier is laid on the foundation. The concrete that forms the first floor of the home is then poured on the foundation. Homes with these foundations therefore do not have basements.

Despite not having a basement, these foundations can also experience seepage. It is worse in these foundations since the seepage will directly affect the living space. Water can find its way into the home through cracks as well as space at the cove joint.

Water seepage is common in slab on grade foundations because the foundation lies on gravel instead of having compacted soil around it. This makes it easier for water to penetrate through to the foundation.

What about the vapor barrier? Vapor barriers are a great way of stopping water vapor from penetrating the foundation. However, they are not effective when it comes to ground water. Water will therefore still seep through the barrier and cause havoc in the home.

Water can also seep into the foundation through hairline cracks in the floor. It can also get into the home through utility lines such as the HVAC vents or mechanical lines that run through the floor.

Foundation waterproofing for slab on grade foundations isn’t just beneficial for keeping water out of the home. It will also go a long way in protecting mechanical systems. These mechanical systems are installed in the foundation before the gravel and concrete are poured into the foundation. There are therefore various pipes, ducts and conduits within the foundation. These are subject to infiltration by water.

It is important to get in touch with a professional foundation waterproofing contractor even if you think your slab on grade foundation is intact. You could be sitting on a ticking time bomb that will cause a lot of havoc when it explodes. Don’t wait for disaster to strike.