Concrete block take longer to shrink, maybe about 8 to 10 years. I had a building in which we used a bearing wall with brick on the outside and 4" concrete block on the inside.

Brick on the other hand expand with age, but not as dramatically as the block shrink.

After about ten years the height of the block on the inside versus the brick on the outside had changed about one inch in an eight foot wall. (There was a running gap that meandered up and down the wall following the whims of the materials movement.)

As it happens a car ran into the building and pushed in a section and I got the shrinkage corrected for the building owner as a part of the repair and the insurance company took care of it.

This shrinking block and expanding brick was explained to me by an older Architect/ Engineer (one of the few people holding dual licenses) who I used to work for. It turned out that his firm suffered a very large loss because of the expanding brick tendency.....a characteristic that brick suppliers do not include in their advertising.

The block mfgrs don't mention the block shrinkage either.

It turns out some things are just learned the hard way.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.