I have a prospective client who is building a new home with ICF walls which he claims will leave a foam surface on the interior walls. He wants to avoid the expense of covering them with sheetrock which is understandable. Is there special priming that is required over the foam, or any other information anyone can provide so I know what finishes I can safely apply over it?? I have no experience ( ) with this type of wall surface, so all advice appreciated!!
Also, any exterior stucco advice as well?
Thanks!

Leslie

Leslie,



We did a stucco application on an ICF interior two years ago.

The foam is usually 2 1/2" thick & medium density.

We used Portland cement stucco, adding acrylic fortifier as our "mix water". (This was before taking the SOIP course)



Cement & lime should have similar behaviors inside the house. No priming is necessary for adhesion.

Because the substrate is only foam-- there is a slight risk of the wall being dented or cracking if hit REAL hard. This has not happened to the work that we did--and we applied stucco about 1/8" thick.



The foam will probably have some groves in it for extra holding power and have a somewhat coarse surface. Both EIFS and concrete Stucco is applied over exterior ICF. But, mesh is usually placed inside a first coat of plaster, for extra rigidity.



If I were doing this, I would use the cement based and resin fortified Velnova, instead of Prontomuro as the base for your finish.



ICF is a great way to build. We plan on one day building an ICF house and plastering both the inside and outside.



David

hey leslie
how did your ICF job go ? here in Utah alot of contractors are starting to use ICF.
And have asked me about how Italian Plasters would work over them, interior and exterior.
So wondering how all went on your project.

Stephen Huls
Monroe, Utah.