Replies

1. 
   CurlyRed | Oct 30, 2004 02:46pm | #1

   Go with foam, but be sure you use the low expansion stuff, as i've seen window frames distort after being insulated with the general purpose foam.  If you've got big windows it might be prudent to put spreaders (sticks cut to length,) against the opposite window casings to resist the foam's tendency to bow the frames.  Foam keeps out wet, bugs, and creates a air seal. 

   BigEr

   Thornbury, ON

1. 
   IronHelix | Oct 30, 2004 03:08pm | #2

   Foam around wood window frames can be a detriment.  

   The foam must be closed cell and have a very low, single digit, absorption rate.

   Foams that hold or absorb water do not allow for drying, hence the frames/rough framing rot from the smallest of leaks.

   I've been told by local window reps...Caradco, Andersen, & Marvin that.....

    "Foam can be a problem, both over-expansion and moisture retention, therefore fiberglass is the preferred choice." 

   Foam with care, flash with care!

   Just a little info to put in your hat!

   ................Iron Helix

2. 
   hammer1 | Oct 30, 2004 06:02pm | #3

   I've used both foam and fiberglass. If you use fiberglass, it should not be packed in tight. I cut thin strips, peel them apart and gently work it into the space with my combo square blade. The idea is to allow it to fluff to fill the space. Compacting it negates it's performance.

   I have some foamed windows in my place, 25yrs. old. You have to know how the foam will expand and place it carefully like a bead of caulking. I have not heard of any problems with the foam absorbing moisture but there are many different foams out there. It can be messy and expensive. Don't get it on you.

   Often the spaces at the header and sill are quite large. Trying to foam those in can take more than one application. Considering the cost and mess of foam, I'm using fiberglass on my jobs unless the owner wants foam.

   Beat it to fit / Paint it to match

1. 
   JTJohnson | Oct 31, 2004 10:03pm | #4

   Hi Joe,

   Right now I'm learning the window trade with a guy that has done it for the last 30 years. We predominately use fiberglass that is cut and stuffed. I have used the DAP foam that is designed for windows and doors ( low expansion, water clean-up and still enough give to it three weeks later to not be concerned) on some of my windows. I think the key to using foam is to remember that a little goes a long way.

   Jeremy

1. 
   AndyEngel | Nov 01, 2004 01:47am | #5

   I think foam is the only choice worth considering. You're not concerned so much about R-value in this small space as with preventing air infiltration. FG is useless for preventing air infiltration -- They make air filters from the stuff, for Pete's sake. Do yourself a favor and go to efi.org. Buy a foam gun and a couple of cans of low-expansion Pur-Fil polyurethane foam.

   AndyArguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.

   Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig