Do foam details rot
my house ?

Ask the pros-January, 2003
By Reggie Bullard




      Are the foam place on's a problem.  We are planning to use them around the windows.  Do they collect moisture?  Are they not long lived?  Thanks.

Of course they collect moisture and even rot your house. In 
my experience there is water trapped behind the foam, saturating everything behind it.
We just tore off some wood moldings that were covered
with mesh and synthetic "stucco" (sic). The installation was
only three years old, and the wood was soaked with water like a sponge.
It seems the EIFS base and finish absorb water like a thirsty
sponge. The water is then trapped against the wall.
These foam shapes would probably work if they were flashed.
For more about EIFS, click here.

eifs foam shapeseifs foam shapes

Flashing all the way back to the substrate should prevent water 
infiltration. I think so, anyway.

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