pourable foam?

[juddspaintballs]

I spoke with a foam contractor in the area today. He said for the size job I have (75'), it would not be cost effective to have him come out and foam my lines in the ground. He said it would be about $485 for him to bring the rig out and do it. He actually recommended buying one of the Tiger Foam kits and doing it myself.

Now, I'm thinking to myself, but if I dug a trench for my lines and raised them off of the floor of the trench with foam blocks, why do I need to SPRAY the foam? Why can't I mix two part pourable foam and pour it around my lines? It would take longer, but a 40 cu ft kit is about $250 vs. $600+ for a 50 cu ft spray foam. One concern I do have, however, is that one marine supply website I was reading said their 2 LB polyurethane foam is not 100% waterproof and constant submersion in water would allow it to get wet. Isn't this stuff the same as sprayed polyurethane with the exception that it's applied differently?

 

[coolidge]

Not all foams are created equal. You are going to want a foam that is 100% closed cell content to be buried underground. Look for the perm rating for each foam at 1",2". Example; the closed cell i am using has at 1" a perm rating of 2.5. Now if you go to 2" it cuts it down to .8. So depending on the thickness you want for your lines i would consider paying the contractor or finding another one.

 

[tom in maine]

Most foam, spray or not, even 2# density will eventually waterlog.
This is not the end of the world since the maximum R value loss is 50% when waterlogged.
Waterlogged foam will pick up 10x its original weight in water.

SO, if you do spray foam, make it thick enough to leave you with a reasonable R value.

DIY poured foam is never going to be as good as a decent density spray installation.

 

[Tennman]

Just re-did my whole underground system. First attempt I used some Tigerfoam with insulation sleeves... horrible mistake. Use the contractor and CLOSED CELL FOAM. You'll end up spending as much or more with the Tigerfoam and will probably under insulate in an attempt to not need another tank of foam. I can't stress enough use the contractor because he'll come with 55 gal drums of stuff and will blow till its right. In my first attempt I tried to skimp on the underground insulation with the result of doubling my work and cost. Everything above ground you can upgrade and fix fairly easily. Read my comments about underground pex insulation in a recent post below. I was throwing away 20-30Kbtu/hr last winter because I tried to save less than $500 that ended up costing me $2000. This is not the part of the system to try to save hundreds of bucks. I'll probably be repeating this story for the rest of my life to other boiler newbie/DIYer's. I think I'll just copy this advice so I don't have to keep re-typing it in the future.

If you PM your email address I will email pics of how we did the FINAL PEX install. I intend to post here in the future but lack the time to shrink and learn how to stick jpgs in a post. But can send 1M jpgs now via email.

 

[chuck172]

How does the stuff work insulating indoor boxed in propane storage tanks?