Housewrap issues for new homebuyers

[bellhead]

? would using closed cell foam in the outside walls as insulation help? This would add a vapor barrier to the outside of the home.

[ShakenStirred]

Originally Posted by bellhead

? would using closed cell foam in the outside walls as insulation help? This would add a vapor barrier to the outside of the home.

You can't have a vapor barrier on the walls in a hot, humid climate. They have to breathe. The minimum perm rating of your Weather "Resistive" Barrier (WRB) in the State of Florida has to be a minimum of 5x greater than your exterior sheathing. In the case of OSB or plywood, the perm rating is about 1, which means your housewrap has to be at least 5 perms. A vapor barrier, which has a perm rating of less than 1, would not only be a code violation, but without breathability, your walls would rot and be covered in mold in less than a year because moisture vapor needs to escape the walls in the cooler months and at night as well.


The recommended perm rating for a WRB in a hot, humid climate, which is roughly from Charleston, SC and everything south of that, is between 5-15. Some will say 10-20, so I will broaden it and say 5-20 is ok, so long as the installation is tight.


There is a difference between a vapor "barrier" and a vapor "retarder." In the case of Weatherization System in the State of Florida, you are installing a vapor retarder.


I personally worked with a builder on a house on the ocean in Ponte Vedra that somebody had covered all the plywood on the exterior walls with a vapor barrier product called Grace Ice & Water Shield, which they use up north a lot. The house had been finished less than a year, and the entire bottom of the perimeter about 4 feet up was completely soaked and covered in black mold.


Closed cell foam can be used inside the walls, between the studs, but only open cell foam should be used for insulating the roof area between the trusses. I've seen where closed cell was used in the roof area, and because the closed cells did not allow the water to drain, leaks were not detected in a timely fashion and the entire roof ended up failing.


SS

[ShakenStirred]

Originally Posted by mrviking

Nothing new here. Proper installation on just about every part of the house is important. With the flood of unskilled labor flooding the construction sites what all is to be expected? lots of problems take time to be noticed and to do their damage. After the warranty is up the builders don't care.

I take issue with your entire statement above. Jacksonville and NE Florida in general has always been way ahead of the curve vs. the rest of the country when it comes to proper WRB installation and Weatherization practices.


Builders do care, as I have worked with literally dozens (over 100 at one point) who absolutely care about the quality of their home.


The recent decline in quality is attributable to a couple factors in my opinion, which are:

1. Lack of qualified labor, and lack of training if and when new labor is hired
2. Cost cutting by the builder in an effort to become more competitive

There is no flood of unskilled labor in the market, there is no flood of any kind of labor in the market. The labor market in fact resembles a barren desert if we are making analogies of that type.


Yes, there are "some" builders that don't care, and that is reflected in their work, but there are many builders who absolutely care, and they remain competitive based on their quality, which is why we have these discussions here.


I find blanket statements about an entire industry to be reckless and unproductive to the conversation. Did you have anything of substance to add? If not, it may be best to reserve your cynicism for more appropriate forums where they are welcome. Just a suggestion.


SS