Interior Foundation Repair
Interior Foundation Repair - Concrete Foundation Crack Repairs
Modern concrete foundations and their concrete footings are made with concrete that is cast-in-place (poured into formboards) with standardized and code-compliant concrete mixes, producing a strong stiff foundation structure with a durability that should last a century. However, this more modern stronger concrete is not flexible like older, weaker concrete rubble foundations, and steel reinforcement bars are not common in residential foundations - these stiff foundations may eventually crack as the building settles into its footprint.
If a crack is wide enough that water can enter it, water will get in the crack, and the freeze-thaw cycles of our Canadian winter cause this water to freeze and expand in the crack and make it bigger. Water may also leak in to your basement, or in cases with high water table, the basement leak through the crack may be more of a flood and can cause more extensive damage to you building and its contents, feed mould growth, and lower the value of your home.
Cracks that are deemed to be "structural cracks", either because they actively move over time, or that they are wide enough you can fit a pencil into them, should be repaired from both the outside and the inside. We start the same crack repair process on the inside as we do on the outside, however, when we waterproof the crack on the outside, we install carbon fiber reinforcement on the inside to prevent the crack from opening back up (see photos).
Interior Foundation Repair - Old Concrete Rubble Foundations
Old houses nearing the one century mark have old concrete rubble foundations, generally with no footings. These foundations are usually left unfinished as they almost never have dampproofing or waterproofing on the outside, and interior finishes would mould, so they are left to dry to the inside of the basement.
Because they are frequently unfinished, it is easy to spot weak areas (see photos), areas that have failed and may collapse if excavated from the outside without first stabilizing / repairing it from the inside. Holes, gaps, and cracks can be repaired with appropriate repair products and given time to gain sufficient strength. A parging overtop of these repairs may be specified for aesthetic reasons and/or to reduce future deterioration of the inside surface of the foundation wall. Once these interior repairs have gained strength, a typical foundation repair and waterproofing program can begin on the building exterior.
