Thread: Stucco causing leaky window?

I had a window leaking from the top of the frame and into the house from a rain storm. There was a lot of wind so the rain was blown right into the side of my house which is stucco with this window. My builder had the stucco contractor come by to check it out and he told me the stucco is like a sponge and it would absorb rain and then drain out the bottom. In my case the rain is getting through the stucco since it's a sponge and then penetrating the rain barrier underneath and getting into my home.

He wants to put a product on the area above my window that prevents the water from penetrating the stucco. He also said once it is applied it does not change the color of the stucco. Does all this sound legit? I have never heard of either this product or that water soaks into stucco this way.

Any thoughts? Note this home is only a year old.

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Originally Posted by Andrew James

He wants to put a product on the area above my window that prevents the water from penetrating the stucco. He also said once it is applied it does not change the color of the stucco. Does all this sound legit?

Does it sound legit? Sounds like he is wanting to apply a BandAid to an open wound which needs cleaning and stitches - i.e., needs to have the stucco removed, the lath removed, and expose what the real problem is ... improper installation and flashing of the window, building wrap, paper backed metal lath, and lastly (not firstly) the stucco.

Sure, applying any type of coating to stop the rain from leaking in is essential ... but only as a temporary fix until the weather clears long enough to perform a proper deconstruction of that area, determine the real cause (one or more, maybe all, of what I mentioned above), then reconstruct that area properly. Kind of like applying a tourniquet to stop the bleeding until the person can get proper medical attention - it helps, will probably save their life (your wall), but you shouldn't leave it on as 'the fix'.

What is this material ? Has it been tested and proven to work for situations like this? The only method i know of that has been tested and proven to work is installing isolation joints between the window frame and the stucco. Get a second opinion from a certified stucco inspector. If this is not corrected you can count on fighting this battle over and over.

First of all, stucco is not like a sponge. Properly applied, it will shed rain without penetration to the drainage plane behind it. Water can penetrate through minor cracks without causing problems if the stucco was properly applied, What you describe sounds more like improperly applied stucco. Perhaps, missing head flashing, casing bead and/or backer rod at the transitions to your windows.

Get another opinion, hopefully from a qualified stucco applicator. Chronic water inside the walls, even in dry Utah, can eventually lead to big trouble.

I did some tests of my own to see where the water is coming in. There is a vent for my dryer that comes out above the window and it seems to be the cause of the leak. i ran water along the top of the window and no water got in. I ran water just below the vent and no water got in. I diverted the water away from the vent with some putty and ran water above the vent and no water got in. Water only gets in when I run water above the vent without the putty diverting it. Now what is the best fix?
Here is what it looks like:

Try just recaulking the vent cover. If that doesn't work, then replace it with the hood type and once again seal it with a good bead of caulk.

Wrong type of dryer vent cover for its location. Try one with a hood over the top and seal the top edge.

Originally Posted by Andrew James

I had a window leaking from the top of the frame and into the house from a rain storm. There was a lot of wind so the rain was blown right into the side of my house which is stucco with this window. My builder had the stucco contractor come by to check it out and he told me the stucco is like a sponge and it would absorb rain and then drain out the bottom. In my case the rain is getting through the stucco since it's a sponge and then penetrating the rain barrier underneath and getting into my home.

He wants to put a product on the area above my window that prevents the water from penetrating the stucco. He also said once it is applied it does not change the color of the stucco. Does all this sound legit? I have never heard of either this product or that water soaks into stucco this way.

Any thoughts? Note this home is only a year old.

There is a simple answer to this. If water leaked through the window then either the weather resistive barrier or flashings are not properly installed. A material like Silane or Siloxane will reduce moisture penetration through the stucco and caulk will reduce water penetration at gaps. But these are band-aids. If you do not deal with this properly now you may be paying for a full stucco remediation later.