Ask Jon Eakes

Last Updated: Saturday, December 17th, 2011, Created: Thursday, November 11th, 2004

Fixing small cracks in a foundation wall.

Randy in Winnipeg has found small cracks in a foundation wall and wants to know how to fix them.

Winnipeg is known for Gumbo Clay, that moves up and down from year to year, so it is likely that Randy's cracks are not stable. I always suggest drawing a line across a crack, putting a couple of measurement marks on the line so that the movement of the crack can be tracked. Check back every month for a year. If the crack doesn't move at all, fill it with anything.

The most common fix for non-moving cracks is Kwik-Plug or some other "hygroscopic" cement -- a product that swells as it cures to lock itself into the crack. It will be necessary to chisel out the crack about 3/8th of an inch wide and deep to get anything into the crack.  One special working caution with hygrosocipic patching material -- mix it in very small batches and apply it immediately, it tends to set in about 30 seconds!  That's not much working time.  On the good side, this means you can actually use it to block an active leak -- just hold it in place for 30 seconds and then move on up the crack.

If the crack does move a little bit, but does not get worse and worse, then use a flexible sealant like polyurethane. Follow this link for information on DIY injection systems.

If the crack is slowly getting wider and wider, call in a professional contractor or structural engineer to find out why.

Keywords: Concrete, Cracks, Foundation, Leaking, Movement, Polyurethane, Sealing, Techniques, Walls, Water

Print Send To A Friend

Article 1364

Privacy | Ruby on Rails Development by Isnor Creative