Need help to a problem

[JeremyB]

Hi Fellas

I attached a picture that I hope you can have a look at and answer for me.

Notice the cement blocks that are under the window frame, there are 2 pieces the run the length of the window. Today I notice that one of them had moved out about 1/2 inch??? I was able to push it back in but is this a really big problem that need to be fixed? I assume yes or are they supposed to float in there . Would this be due the harsh winters and extremely hot summers causing expansion and contraction?

any help would be great


Jeremy

 

[BridgeMan]

Loose sill blocks are not that uncommon. They are (usually) the result of either an inadequate amount of mortar underneath them during initial construction, or deterioration and the resulting lack of bond of the mortar that was used. Freeze-thaw cycles will always tend to work on members like this and their bonding material, and over time can result in the members breaking free.

A proper repair would consist of removing the blocks and all mortar completely, cleaning things up with a wire brush to promote good bond of the new mortar. Re-install the blocks using proper mortar for your climate, and don't forget to renew/replace the flashing if the stuff that's there is damaged (or missing). Using a flexible, self-adhesive flashing will ensure that the new mortar will have a tight bonding surface.

A temporary repair of just removing any obviously loose mortar from the visible top, vertical and underside joints, followed by placing a few beads of good polyurethane caulk everywhere the mortar was removed. Doing so will buy some time before undertaking major re-work as initially described.

 

[JeremyB]

Thanks Bridgeman I appreciate it.

Yeah, I will caulk it to buy some time. Seeing that we haven't had any rain here in about a month and little forecasted for the coming weeks water wont be a problem yet. Caulking it wont cause any sort of problems though will it?

Thanks again

Jeremy

 

[BridgeMan]

If you use industrial-strength caulk, it could be a bugger to get completely off the blocks, window frame and bricks. Maybe a cheaper latex painter's caulk would work all right, while still not that difficult to remove.