This is a Just Curious question that's been bugging me for years: every large commercial concrete block structure I can recall seeing being built has had small metal (aluminum?) tabs sticking out from between the blocks. I'm trying to figure out the purpose of these tabs...?

Knowing very little about construction principles, I've only been able to guess that they have something to do with the curing of the cement between the blocks: do the tabs conduct heat into or cold out of the interior, speeding up drying? do builders check if the tabs can be pulled out to see if the cement has cured?

Please help me get on with my life...


MJ4U
Monte Joe

Those "crinkle" ties work great in tension, but are very poor in compression. In other words, put a heavy wind load on a wall with a cavity, and they can fail, causing the brick mortar joints to crack. We don't allow them in any work we do. There are countless heavy gauge wire-type ties that are much better (and more expensive) in compression. Just some food for thought.

Just a note about the use of the ties relating to the big picture -

Most of the uses for corrugated ties I have seen in the world were for composite masonry walls with a gap of less than 1". The sucess seems to be due to the short unsupported length of tie and the rigidity of the structure. In some countries a small amout of mortar is left on the tie to stiffen it. Often a small dab of mortar placed on the tie when the brick are laid. This is not according to our code, but it frequently comes up in the writing of masonry codes.

Obviously, for true cavity wall construction, a proper tie should be used even though they (eye and pintel systems) have some give.

Many of the problems with cracks in brick walls are due more to the lack of rigidity of the back-up. For wood stud and steel stud walls, the brick veneer is often stiffer than the back-up.