Has anyone have any comments on Demilec foam insolation

[SPIKER]

One thing that concerns me is the open cell foam will absorb water. the closed cell foam does not let water penetrate it.

while both are great at sealing up air, the closed cell will provide stiffness or rigidity where as the open cell is flexible. what has become popular here is to use a 25/75 one coat of closed cell on exterior surfaces to a 25% depth of wall then filling the rest with the less expensive open cell foam.
there are other options as well such as blown in insulation but in the wet environment I would suggest the closed cell or the half & half mix.

Mark

 

[Para]

As far as I can understand the opencell wont let in water or Humidity unless ist constant water like a burst pipe or a big hole that lets in rain water and it sits there . But becuase it breaths that will deal with keeping the roof dry .

May main question is does it breath as well as advertised to let my roof not have condensation as it will rot here in the damp Irish weather.

Yes I am sold on the facts that it doesnt let in drafts becuase of the expanding qualities of the foam. But breathing is also important

 

[keegs]

I built a house last year for my Mom and used a polyurethane foam insulation. It was a different brand/formula than Demilec - in fact it has an R-value of 6 or 7 per inch as opposed to the 3.81 per inch listed at Demilac's web site. So what we did was sprayed in 4 inches into a 6-inch stud bay and left the air space to the warm side.

Regardless of which poly-foam formula that you use, you will not regret using that kind of product. I'm not as up on the ventilation and water vapor protection needs in the south, but in the colder climates one of the nice benefits of sprayed foam is that it completely seals out drafts and acts as your vapor barrier. If your house is close to a road you will find sprayed foam to be much quieter as well.

The only caveat is that the house will be so tight you REALLY need to install a heat recovery ventilation system (or in the south an energy recovery ventilation system) - just Google "hrv/erv" for details about that. Without a supply of fresh air you are guaranteed to get "sick house syndrome" - more colds, allergies and respritory problems, etc caused by lack of fresh air.

Do it - you will not regret it.

Paul

Hi Paul..Where are you? I'm in Aroostook county between Houlton and Presque Isle. I looked around last year but could't find any foam installers. I have new construction and the walls are still open. Got any ideas?

 

[circlelake]

I'm in Minnesota and installed foam about 3 years ago and love in. From what they told me at the time if I use open cell I would need to install a vapor barrior. I wouldn't need to do that with closed cell. So went with closed cell. I like the 25/75% idea. It would have probably saved some cost and maybe they are using this blend to eliminate the vapor barrier. The closed cell is so tough it also helps keep the bugs out. They sprayed right underneath the floor to over the block wall. A common area where the critters get in. Another main reason I did foam was to help eliminate a problem with a barking dog next door. I sleep so much better now days.