I've got new doors on order to arrive in two weeks. The gap between the rough opening and the old door jamb has been stuffed with fiberglass insulation. I was told to use an expanding foam products, however the guys down at the hardware store suggested not too. The R value rating is about 5 for these products. Is that better than fibergalss? I was told to be careful not to spray too much foam as the expantion could cause problems. Any thoughts/suggestions?
There are two kinds of foam.....one is a poly uerathane ( mis-spelled I'm sure) type that expands greatly and gets rock hard when it sets....that kind you DO have to be very careful what you use it on....a bit too much and it will push a door or window jamb so tight you can't use the door.....and it's a real pill to dig it out...
Great Stuff is one brand of this
The other is a latex foam that doesn't expand near as much and remains soft....it is especially designed for doors and windows....I've used it with no problems. DAP makes the stuff I use....
Even fiberglass can be overpacked and warp a jamb...the key is to place enough to do the job, but don't cram it in.....you don't get as much insulative value by cramming it tight either.
Like Andy said -- Even fiberglass can be overpacked and warp a jamb...the key is to place enough to do the job, but don't cram it in.....you don't get as much insulative value by cramming it tight either.
Cramming fiberglass in actually reduces it's rated R value. It needs its 'fluff' to be effective. If you put an R-13 batt into a 2X4 wall, you get R-13 performance. If you cram an R-19 batt into that wall, you actually will only get about R-11 or R-12 performance from it.
the latex foam is the best bet because you can paint over it
Have any of you ever experienced any problems (near or long term) as a result of using the Dap flexible latex foam sealant on vinyl window remodeling installations?
I recently discussed such sealing products with a Tech Service representative of a major vinyl window manufacturer. He said the he has had some problems when using them - but declined to give me any specifics about what those problems were.
With vinyl windows, his recomendation was to stuff fiberglass between the window rough opening. This allows the insulation to remain effective even when the window expands /or contracts due to temperature changes.
I have a situation where the bottom corners of the frame on some of my vinyl replacement windows is quite cold. These are in brick masonary openings. Rather than using small shims stuffed fiberglass insulation, I used 3/8 exterior plywood to fill the entire space between the rough opening the window.
To fill the remaining gap (which was tight for the most part, or less than 1/16 at the worst point) I used Dap latex foam which did get into the small gap. Where it couldn't fill the gap, it formed a heavy bead over it. On the outside, I used custom fitted vinyl extrusions which completely cover the gap the wood fillers. This was also sealed with a very high quality flexible caulk that was recommended by my window supplier.
But after hearing this persons comments, I wonder if I did the right thing. As a result, I'm reluctant to install the interior trim until I'm more certain about the possible future effects of using Dap latex foam as a sealant. Or the need for stuffed fiberglass, which means removing the wood spacers to do so.
Learning about your experiences with this type of foam in similar (vinyl) installations will be very much appreciated.
Best regards, Dick
You need a gap (1/4) on each side and the top of a vinyl window so that it has room for expansion. You can fill that gap with fiberglass insulation -- it will compress as the window expands. A foam insulation sprayed into that gap is too solid to allow the window to move. That is why every window mfgr. that I am aware of says don't use the spray in foam. Most will void the window's warranty if yu do.
Lefty,
Thanks for the reply, but you're reciting the window manufacturers standard party line - because that's what they know have done for over 20 years.
If you ask the foam people, they'll tell you that very soft, cushion like, flexible latex foams are great for window installation gap filling. Even some professional window installers builders say the same. See Andy's reply just above my post.
From my experience, latex foams are nearly as soft as fiberglass wool. You must be thinking of polyurethane foams which are quite rigid.
rckowal,
True, but that is essentially what is stated on the window's warranty. Latex foams are soft, and will probably work just fine. But if you use a spray in foam and at some point have a warranty issue, the fact that a foam was used will give the mfgr. an 'out' from honoring the warranty. The consumer/installer simply needs to be aware that even though using a latex foam will probably work just fine, the USE of that foam will probably void the window's warranty.
I was going to use Weather Shield. Its a 'low expanding foam' that's designed for windows and door frames (so they say). The expansion rate is 25%. There are truly two camps on this issue. One using fiberglass and the other using expanding foam. The r value on this product is 5.4 per inch, but I cant tell if its poly uerathane or not. How can I tell if it a poly or not.
Cicco,
Latex foams remain fairly soft. If you push on it with your finger, it will (or should) move. Urethane foams set up and become hard and stiff. You can put a dent in it with your thumb and a lot of brute force (or your thumb will break, whichever comes first!!)
rckowal,
Yes, there certainly are 2 schools of thought on this issue. Which method I choose when installing a window is determined by reading the window's warranty. The 3 lines of windows that I offer all make pretty much the same statement -- 'if you use a foam insulation around the frame, the warranty can be voided by the mfgr.' Rather than running the risk of leaving my customer without a warranty on their window, I use fiberglass. Now, if I am installing a window that the customer purchased from who knows where, and no mention is made regarding the use of foam voiding the warranty, then I have no problem using the foam.
Lefty is the window installing expert. But I was a Plastics Engineer for 40 years before I retired; so I know foams caulks - which are actually plastics.
Although the package usually says what type of foam it is, another way to tell is to read the clean up instructions on the can. If it cleans up with water, it's latex. If it says to use some kind of solvent - like paint thinner or acetone - it's polyurethane.
Great Stuff brand is polyurethane, even if it says minimal expanding! DAPtex is latex.
Also, as Lefty recommends read the window warranty. Mine says absolutely nothing about the use of either fiberglass or foams. It only says that the window must be properly installed - which is very broad non-specific. But my window factory rep said that although they recommend fiberglass, they sometimes use latex foam to seal small openings if they can't stuff fiberglass into the opening.
One last thing, don't rely on any foam to act as a caulk or sealer that's exposed to the weather. They will not hold up. If foam is used, you must caulk over it. White Silicone II is great on the outside. On the inside, a very high quality, premium latex is fine. Latex is easily paintable, but Silicone II isn't.
Tags: door, window, foam, latex foam, window warranty, expanding foam, fiberglass insulation, rough opening, vinyl window, will probably
