What is frost adhesion?
Frost adhesion is when frost (via the dirt) sticks to the concrete foundation and expands, severing the foundation horizontally below grade (grass level).
This has been very prevalent due to extremely cold winters the past couple of years in Ontario. Usually we see it on a small scale in lifted walkways or sidewalks... on a larger scale, the movement is with your house - we have seen houses lifted as much as 18" out of ground! Mother Nature at her best...
How is frost adhestion damage repaired?
The fix is similar to waterproofing but with a few added elements - dirt removal is first required and then it replace with a non-frost susceptible material. In some cases, depending on severity of the heaving, helical piers are used to re-support lifted footings and stop further movement.
CASE STUDY: FROST ADHESION REPAIR
The following job was a result of poor drainage, frost susceptible soil, and no slip-plane.
Ontario Building Code currently does not require continuous weeping system around the garage, nor do they require Delta MS around the garage (the slip-plane) inhibiting frost adhesion. This typically happens in non-heated living spaces, such as garage areas, porches and cold-cellars.
Below you can see the physical movement of the brickwork - a buckling of the bricks, and in the garage floor slight heaving. Digging down on the outside of the exterior wall revealed a horizontal crack that measured almost 35 foot long, severing the concrete in to two pieces with several inches of space between the upper and lower sections.
To fix this issue, the garage floor was removed, a trench was dug on the inside and outside of the wall and a C-channel 3/8" metal solution installed on both sides of the foundations. The C-channel is used to compress the two halves together, thus straightening and re-aligning the walls. The crack was cleaned and then filled with non-shrink grout.
A new weeping system was installed around the garage, tied in to the regular house weeping system, then backfilled. The garage floor was replaced.