bertram31.com

Hi,

I have the same situation. I used the slow-rise TigerFaom product. It comes in a pair of containers the size of propane tanks. If there is insulation in the walls, it is still possible to use the tigerfoam without removing the old stuff. Maybe not in every situation, but if any was the old thin 1-2 inch batts, it works great.

You use a long piece of tubing on the end of the foam nozzle to reach the bottom of the stud cavity. If there is insulation in some of the bays, make sure the hose is running alongside the insulation and not pushing a batt down to the bottom. The slow-rise tigerfoam will pool in the bottom of the cavity and slowly rise to fill it, compressing any existing batt insulation against the wall.

For prep, you'll want to get into the crawlspace or basement to add some blocking to the bottom of each stud-bay. Depending on when your house was framed, there may or may not be some sort of blocking there already. If there is, remove several and make certain what it's doing. In my house, there were short plank tacked between studs, but behind the plank was a loose concrete fill that would have allowed the foam to seep out.

I used some great stuff to fill gaps around the bottom of the bay and the top of the filler. I used great stuff since it expands to fill cracks and held plastic over the back of it while it worked.

There were several bays where that had nothing in the bottom. On these, I used some 3/8 pink poly insulation board and latex caulk to seal the bottom and then nailed up a 2x below the poly and across the bay for support.


So anyway, once the end of the tube was in the bottom of the bay, you start filling, while at the same time, slowly withdrawing the tube from the wall. You won't need to pour foam all the way up. It's going to expand and do that part on it's own. I probably filled the bottom third and it expanded to fill the whole bay.

You need to keep the temperature of the foam at around 78 degrees. I built a covered box out of 2" pink poly that was big enough to hold the pair of tanks and an oil-filled radiator to maintain the temp. With that contraption sitting on a small wheeled cart, it was easy enough to shift the tanks around each room as I progressed.

You don't have any slack time when using the foam. None. You have 30 seconds between the time you let you finger off the trigger until you must begin spraying again. Any longer than that and there is a good chance you'll need to change the nozzle. All prep work must be done before your start using foam. Everything. So cut out the fill holes in the top of each stud bay, have everything out of the way so there is nothing to move. Practice how you're going to move and handle the nozzle and filling tube (I used clear tubing from the borg) and the moves from one bay to the next. It's not something you'll want to learn on the job.

I also removed all of the old work electrical boxes and wrapped them with blue painters tape and re-installed them. The existing new work boxes I checked for missing knockouts. I found a few. These I taped from the inside and stuffed with chunks of old nerf ball.

The foam will go anywhere you let it. Think ahead :-)


Buy some extra tips for the nozzle, consider getting the longer hose kit. Each pair of tanks come with a hose kit, nozzle and a few tips. The extra tips are handy if you need to stop spraying foam longer than the 30 seconds. You'll definitely want to wear old clothes. I'd advise you to also wear a hat and bandana around your hair. A full face shield is probably a good idea, too. The last thing you want to do is get this stuff on a mustache or beard. Gloves are mandatory. It's a right mess if you get it on your hands.

It is expensive, but worth every penny. Even without the tax break you can get.