When we purchaced our home we saw that the plaster around the windows was damaged due to moisture. The home inspector explained that the windows were not installed properly, but he assured us that the problem had been fixed. So, we re-caulked the windows just to make sure we wouldn't have a problem. We then repaired the plaster and repainted the interior walls. We are now noticing that the paint is beginning to blister again (less than a year later). The windows are thouroughly caulked, and this is only happening on the weather sides of the house. We also checked the bricks and morter for cracks, and there aren't any. Any ideas?

Is the damage "all around" the windows, or mostly below?

Are the areas with this problem on more than one floor of the house?

What was the installation problem that the inspector mentioned, and what was the fix?

If water is still getting in, the place to check is the roof, gutters and downspouts.

... but if the walls were not completely dry before the repairs were made, that could cause it.

And if the patching was not completely dry and primed well before the paint was applied, that could cause it too.

Do you think it might be one of the latter issues?

Thanks for the reply Rick!

The problem was 'all around' but now it is mostly below (so far). The inspector said that the installer probably didn't caulk the window properly. I must say that the current blistering is very minor (so far), but I don't think it should be there at all. It seems that the caulking solved most of the problem, but not all.

I've had the roof checked, and it is good.

The problem occurs on the first and second floor on the North and West walls. These sides take all the weather. I only have problems on these sides.

... but if the walls were not completely dry before the repairs were made, that could cause it.

And if the patching was not completely dry and primed well before the paint was applied, that could cause it too.


This might be the problem. I didn't notice any moisture when we patched the walls, and we waited for the patching and the primer to dry according to the instructions. The paint on the patching on the top of the windows is not blistering - only on the bottom. Any other ideas?

Do I need new windows?

In your re-caulking, did you do so on the exterior?

Are the interior of these windows, and the sills, dry?

Get new windows? I'd say no: unless you were considering new windows for other reasons (better insulation, looks, etc.)

If the windows are caulked good, and if the drip edge above them (if you have them; not all window openings do) is in place correctly, then some fault with the windows is pretty much ruled out.

Yes, I caulked the exterior. No part of the interior window or sill is wet. I discussed your comments with my wife, and she thinks you might have hit the nail on the head. She said that we did not prime the patching work that we did. She worked at Sherwin Williams for 5 years. She agrees with you that this might be what is causing the blistering. We'll keep an eye on it for another year. The windows are performing well other than this blistering problem.

Thanks again for your help, Rick.

You are welcome. ;)