Best Minimal Expanding Foam?

Experts,

What brand(s) of minimal expanding foam do you guys use?

I have seen some comments about folks using "Great Stuff" which is quite inexpensive and easily available. I have noticed that some Anlin installers use "Illbruck", which is a german product and quite expensive. It is not very easily available but the installers say it is a great product.

Want to hear your opinions on this subject.

I use Hilti.

http://www.us.hilti.com/holus/modules/p ... /chemicals

Hi,
I reccomend that you use fibreglass insulation cut into 3 1/2 inch width for insulating the windows. Foam (even minimum expanding) can bow in your window frame causing warping and problems opening and closing your windows. Alot of the vinyl window mfgrs state in their install directions that they dont reccomend the foam. If you are skilled in it's use, I have known people to use it, but I stay away from it, and as a novice installer, I would reccomend that you do too.
Regards,

You are obviously talking about expanding foam. The kind we use is a non-expanding foam that stays pliable. It puts no pressure on the frames at all and does not bow them.

Polyurethane foams = bad.

Latex foams = good

I prefer Dap Latex Door and Window foam. It's impossible to bow out a frame with it so it's safe to use on vinyl windows. Even overpacking fiberglass is a bad thing- it has to be kept fluffy. Fiberglass doesn't stop air, it only slows it. And overpacked fiberglass loses any r-value it once had.

Greetings,

FOAM EXPANSION

Terminology in the Aerosol Foam Sealant foam world is becoming defined. Foam Expansion is classified how much the foam will post expand or collapse after dispensing. The way in which this is measured is not yet harmonized which is why each manufacturer has data that is different. This makes selection a bit complicated as many of the manufacturers have different methods on how they measure expansion. New standards for this property should be published soon giving harmonization to the industry.

FOAM PRESSURE

Low Pressure Foam relates to how much pressure an Aerosol foam sealant will exert. AAMA 812 voluntary practice provides information that may be valuable in making foam selection that is low pressure. One rule of thumb is to look for foams that have pressure build data less than 1 psi. AAMA 812 is one way to evaluate the pressure build of a one k foam.

Key take away

Low Expansion does not mean Low Pressure

It is possible to have a low expansion foam that has a pressure build that can distort a window frame.

Reccomendation

Hilti CF 812
http://www.us.hilti.com/holus/modules/p ... OID=-17972

That's what I use.
They also have a new can with a new formula for when it is cold outside.

The Dow Pro series have the same gun-applicated, low pressure products available at about 30% cheaper than Hilti. Identical performance, easier to get and a third less money as it's manufactured by a company considerably larger than Hilti. The pricing difference mentioned is contractor cost but probably carries over to consumer cost as well.

anyone use backer rod??? we use a lot of it here in the NW.

Key is having something behind the fillet bead of sealant to prevent cracking.

Uh -oh...did I just start a caulking discussion?

What a great question flygirl!! A lot of people are missing out by not using it. It helps makes a 20 year caulk last 20 years! It has advantages for windows for both exterior and interior use. I think you were mainly referring to its use on the interior for insulation, but I'll touch on both interior and exterior.

INTERIOR USE
Windows should be properly sealed for air and water infiltration during installation to perform correctly. To seal the window on the interior (we'll get to the exterior in a bit), one can seal the gap between the window frame and rough opening using backer rod and caulk. Loose fiberglass insulation stuffed into this gap does not stop air flow although it will slow it down, so it will insulate the gap but not seal it. A non-expanding insulating spray foam that will not bow the jambs or void window warranties will work also (that's actually my 1st choice, since it both seals and insulates, and is easy to use). However, since some companies still have warranties that discourage or prohibit the use of foams, the backer rod solution is a fine choice. See the following graphic for the use of backer rod for interior use:


EXTERIOR USE
Flashing, tapes, caulks, and backer rod are among the materials used to seal the exterior for air and water infiltration. Backer rod is recommended by many caulking experts and windows companies. It has lots of advantages.
1. Without backer rod a caulk joint will potentially fail quicker. The backer rod (a polyethylene or polyurethane rope foam material) controls sealant depth - it provides a backstop to prevent the caulk from sinking too far into the gap. The caulk should be tooled concave to form an hourglass shape against the backer rod for optimal longevity. Ideally a caulk joint should have the sealant depth 1/2 of whatever the sealant width is (but a ideally a minimum of 1/4" deep). Never completely fill a deep joint. Doing so wastes caulk and makes a good, permanent bond less likely. The depth of the caulk should never exceed the width. Companies vary on their minimum and maximum recommendations - some use backer rod in all situations, others (for example) in joints only wider than 1/4" or deeper than 1/2", but again the principle is the caulk joint depth should not exceed its width and preferably should be about half as deep as it is wide.
2. It provides a back-up seal in the event of failure of the primary caulk seal and insulates the underside of the sealant .
3. It provides a firm surface with backpressure to tool against forcing the sealant to the joint walls.
4. It prevents failure of the caulk due to "three sided adhesion." The caulk being used should adhere to the sides, but not the back, of the gap. If the caulk adheres to the back of a joint as well as the 2 sides, it limits the amount of movement that a joint can accept without inducing a tear. This is more crucial in large window composites or any joint that experiences a lot of expansion and contraction.

So backer rod, when used with sealants, provides a "belt and suspenders" seal system - two different materials working to perform the same function, and as a bonus each working to extend the longevity of the other. Here's two examples of the exterior use of backer rod:

also

wow - we are all such nerds! Love the pix you attached...what is the source?

I just pulled them off various websites (thank you Google) and cleaned them up a bit (thank you Microsoft Photo Editor).

"Window Geek" sounds so much more contemporary than "Window Nerd," don't you think so?

Yep - guilty! A window geek I are.

WINDOW GEEKS UNITE!!!! Backer rod?? What a great idea, just make sure to choose a very soft celled brand. The harder, more dense backer rods have a tendency to off gas when punctured, causing bubbles in caulking.

Hey - thanks, mman! Didn't know that.