It’s time to insulate the outside walls of our home. After interviewing three vendors, a question has arisen which I bring to the collective wisdom of The Dope.
Two companies would pump the insulation through the stucco, apply some kind of patch to the vapor barrier…and done.
The third guy wants to do the job from inside the house. He insists that if the vapor barrier is breached, it will never again effectively keep out moisture and he’s willing to guarantee his work.
I’ve never heard of this and it seems to me that in this day and age some kind of patch and strong glue would repair any damage. I’ve seen scores of homes with the the tell-tale holes in the outer shell, easily covered by paint. I’ve never heard of people having problems with vapor leaks.
We have paneling in three rooms which would be impossible to patch, but crown molding and a baseboard could be added to cover the holes. I like molding, but don’t need added bother and expense just now.
Is there an insulation guru out there who can shed some light on this situation?
the vapor barrier is on the inside of the insulation behind the finished wall to keep house moisture from condensing in the cold insulation (at the cold outer wall). there is an infiltration barrier that would be behind the siding.
houses can have blown in insulation from either inside or out. it depends on the situation and repair. stucco could likely be patched and look good. loss of some outside infiltration barrier from outside application would not be a big problem as loss of some vapor barrier on the inside.
in a cooling climate the vapor barrier may be placed on the outside of the wall or there may be no vapor barrier used.
in an equal cooling and heating climate no vapor barrier might be used.
I have to point out that the vapor barrier must on the heated side of the wall – i.e. the interior surface. Cutting into the exterior surface should not touch the vapor barrier.
A stucco wall does have a layer of water proof material (often a type of tar paper) directly under the stucco. This is to prevent any rain water which gets behind the stucco from entering the wall and is not a vapor barrier.