We are closing off window openings of 4' high x 20' long in an old gymnasium. Construction is 8" concrete block interior walls and brick exterior built in 1952. The existing windows are 1" wide steel frames anchored into the wall by a concrete cap poured around them. The concrete cap slopes about 1.5" over about 5.5" for diverting water. It may be too costly to remove the windows, level the cap and lay 8" block, so we are condisering leaving the windows, and placing 4" block on the sloped cap, using mortar to level out our first row. We would tie the block to the brick exterior by busting out the glass and running through, but are concerned about differing expansion/contraction between the different block sizes. Also concerned with only using mortar to leve out our cap for our first row. The building is located in central Indiana. Any suggestions?

Ok, if this building is worth saving, you need to do it right.

1- The steel windows are usually installed with tabs that stick out from the 4 corners, but take a sawzall with a metal blade and run it along between the metal and the block and brick and find out how they are attached and cut them out. The first one will be the hardest, and they will get easier.

2-Once the are out and you have cleaned up the sloped sill by chipping it out with a "hammer drill" which you can get with a blade bit about 2" wide.

3-Now lay new block on the inside, it should not be hard just follow the lines of the existing block.

4-Fill the outside the same way, with matching brick or whatever you can get depending on the buildings use, and how you want it to look like when finished.

You will have something that will last another 50 yrs and not a mess.

Good luck

Roger