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Basement Leaks Through a Concrete Block Wall

Concrete Block Wall Basement in Toronto

Many homes in Toronto and the surrounding GTA have poured-concrete foundations, but some of them are made of concrete block, which is often referred to as concrete masonry units (CMUs) or cinder blocks. The walls of concrete block foundations sit on a footing which is a concrete-poured pad that is wider than the building’s foundation wall. This helps to distribute the home’s weight load. The foundation’s construction starts with pouring the footing inside a trench which contains metal or wood forms. The footing needs to sit lower than the freeze line and possibly deeper if there’s going to be a full-height basement.

 

Foundation Footings

The footing’s thickness and width depends on the construction and size of the home as well as the soil’s load-bearing capacity. During the basement excavation, the first row of concrete block is laid on the footing when it has cured to describe the structure’s perimeter. For foundation walls, the typical thickness of the concrete block is eight inches. However, foot-thick blocks are sometimes used for heavier loads and higher walls. More courses of block and mortar are added in a brick-like pattern until the proper height is reached. At this time, any openings and windows are built and the mortar in the wall is given time to  cure.

If there are hollow cores in the block walls they may be filled completely with mortar, but usually the edges of openings and corners of the wall are filled. In addition, extra strength may be added with steel rebar. Once the walls are finished the basement floor is poured with concrete and the ground floor framing is completed. The foundation is now supported at the bottom and top and it’s backfilled and compacted with soil while construction begins above the ground.

 

Fixing a Leak in a Concrete Block Foundation

Poured-concrete and concrete block foundations both have identical load-bearing strength, but concrete block walls are more susceptible to any type of lateral pressure which can result in seepage problems. This is because water can seep into a basement through concrete block walls via the porous blocks and any cracked mortar joints. It’s recommended that you waterproof a home’s block foundation by installing a waterproofing membrane to the exterior. This method can be done while the building is being constructed or by excavating around it.

The exterior membrane consists of asphalt-modified polyurethane. It’s applied in a thick coating to the exterior of the foundation walls and it created a barrier which helps keep out water. The waterproofing membrane is different than a damp-proofing spray as the spray is a thinner liquid which is sprayed over foundation walls when the home is built to keep condensation out of its interior. The membrane can be improved with exterior drain tile when the water table is high. The drain tile is designed to carry ground water away. In addition, drainage board can be installed on the walls as a method to help protect the exterior membrane by channeling the water downward.

If you don’t have the option of exterior waterproofing, then interior drain tile can help keep a block wall from allowing water through it. This often sees the installation of a vapor barrier on the inside walls which transports any water to the drain tile. This can be kept from view as a finish wall can cover the vapor barrier.

No matter what the reason is for your damp basement, if you have a concrete block foundation that needs to be waterproofed please feel free to contact our team of professional contractors at Nusite. We have over 30 years of experience dealing with concrete block walls in the GTA and will gladly schedule a visit to your home for a free inspection and estimate.

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NuSite Group is a Toronto based basement waterproofing and foundation repair company that specializes in Basement Waterproofing, Basement Lowering, and Foundation Repairs. Call us today at 416-622-7000 or 905-731-1228 for a free in-home estimate and inspection.

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Customer Testimonials

Interested in working with us? Check out some of our customer testimonials below and find more on Homestars. We are one of the highest rated basement waterproofing companies in Toronto

Mark Lipton - Homestars Review

Basement Waterproofing

Our basement leaked! Of course . . . we bought a 100 year old house! But my office needed to be in the basement permanently. I interviewed 10 different companies until we decided on the Steinbergs and their crew at Nu-Site! They are professional, reliable, courteous, honest, and they really make an effort to communicate with the client about every step of the process.

Sara Jack - Homestars Review

Foundation and Waterproofing Repairs

After several years of chronic leaks, we decided to have our basement waterproofed once and for all. The team over at Nusite was professional, answered my questions during the project and stayed within their quoted price....which is always a concern for me when working with contractors. Great job overall

Joshua Persaud - Yellowpages Review

Basement Waterproofing

Had several cracks in my basement wall and they would leak whenever we had a heavy rain. It started about a year and a half ago and seems to have gotten worse over the past 6 months. I tried having my neighbor seal it, but it started leaking again within a few weeks. Called several waterproofing companies and got several quotes. Finally went with Nusite contractors for the job. They gave a reasonable quote and I liked the guy that came by for the estimate. They stayed within budget and cleaned up before they left. It's been almost 3 months now and it seems to be working great.