We recently had a concrete patio laid down. The patio abuts the back of the house but no expansion joint was installed against foundation of the house. The contractor said these were not needed since expansion joints were installed in several ares of the patio. Is expansion joint necessary against foundation to prevent problems? Thanks

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Originally Posted by bobbyok

We recently had a concrete patio laid down. The patio abuts the back of the house but no expansion joint was installed against foundation of the house. The contractor said these were not needed since expansion joints were installed in several ares of the patio. Is expansion joint necessary against foundation to prevent problems? thanks

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Not usually... if the new concrete has at least one edge that's not abutted by a wall or another slab... as long as the new slab has a direction it can take to settle... it should be O.K. I usually install expansion felt (or similar) whenever new concrete is poured to a wall but it's really not necessary. The "control" joints (grooves in the concrete) should be made no less than 8' apart. We know that concrete will crack... we want to control where it happens.

I always install a felt joint againist an existing wall. It allow the pation to settle more evenly. If it setles now it can hang up on the house foundation and settle with a slight tilt. It is too late now though so just live with it. Kstar4u is 100% right, all concrete cracks.