Spray Foam Insulation

[Guest RemedyCNC]

Anybody have first-hand knowledge of spray foam insulation?

I have a full basement. I have a room off the basement which is under the front porch. It is about 5 feet wide and 15 feet long. The "ceiling" is corrogated steel which has been primed.

Due to the transfer of cold from the outside, it sweats. Bad! I have a dehumidifier in the room but it doesn't work well in a cold room. If I keep the room warm, it sweats even more.

The previous owner put up 3/4 foam board and glued it to the ceiling. It was adequate but started coming down recently.

My question is will spray foam work in this application? I am worried about it acting like a sponge if it does get wet and will make a huge mess. Water can come in from the porch if it is hosed off or the rain hits just right. Not much but if the foam soaks it up, could be a problem over time.

Anyone else have this type of room in their basement? Suggestions. Thanks!

[Guest Bonedaddy]

I don't think spray foam will absorb water and will seal things real well and bond to damn near anything. Some types actually need moisture to bond well, though. So check with a local contractor to see what they are using and then research it or call the supplier.

[Guest BEARMAN]

I used it on the inside of my wood planked front porch to seal the cracks. Worked real good, and has not absorbed any moisture, however, some has come off and had to be re-sprayed over the years.

Good stuff...but pricey. IMHO

[Guest Bonedaddy]

It does tend to harden and get brittle over the years.

[seez52]

have got the exact same problem, or used to. I've got a zombie room, or actually a storm room, yes, storm room, that's what it is sorry:nervous:, that is directly under my porch. The cold transfers from outside and caused it it "rain" inside. The humidity and warmth of the inside was the issue, even a dehumidifier was not enough to keep if from raining.

I used 3/4" pink foam sheets. Tried gluing them with construction adhesive, but they eventually started to come down in spots. I ended up using a Trakfast gas nailing gun to drive nails through fender washers. The nails went right through the corrugated steel and into the concrete above, and they ain't coming down now! Usually if you just put one at each corner, the adhesive will do the rest. You'll also need to tape the joints

I do get some cold transfer through the nails and now the fender washer tends to sweat a little. I need to go back and glue some foam over them to fix that. You just need to keep the air off the cold parts. You could probably get by with 1/2" foam, maybe.

Not sure how you'd get the spray foam applied to a ceiling if you're talking about those little cans,and it's gonna look kinda ugly. The pink is real purdy. There are companies that use high pressure foam sprayers that would probably work. I waited until the summer to do mine so the ceiling was real dry.

[Guest yankee2010]

First thing first, seal the source of the leak then completly water proof the walls ie: drylock, correctly don't half ass it. Use a membrane to seal the ceiling and down onto the wall then if you like put some foam back on the ceiling. Your concrete floor is also a source of moisture and depending on the door going into your room and weather or not the remaining basement is sealed you may still get some moisture in there.

[Guest yankee2010]

Oh, the answer to your question is yes. My only knowledge is that I have used it to waterproof foundation walls. Not a fan of it used for waterproofing.

[Guest RemedyCNC]

Seez52, we have the same setup. I, too, thought about a mechanical fastner as well. But the spray foam I am looking at is a big do-it-yourself kit. Comes in a tank like freon does and includes the spray gun. Not cheap either. That is why I am posting up hoping to get some other input.

Yankee, there is really no specific leak. It is a room, completely below grade. The walls have several coats of Drylock but still seep a bit when it is really damp outside. No puddles, but you can tell there is moisture. The dehumidifier helps. Problem is the temperature differential. I would guess there will be condensation unless I can get the humidity down to 0, which ain't gonna happen!

Thanks for all the input. I think I am going to call the manufacturer today and ask them. I hope for a straight answer and not a salesman answer.

[seez52]

I put the drylock on mine, 3 sides of the room and it helped immensely. Was one pain the a$$ to apply, but it seems to have knocked the moisture level way down. I'm considering putting a 6" branch off my central HVAC unit into the dead end of the room and installing a vent in the door which is on the other end just to keep some conditioned air flowing through. Don't think it will be a big hit on my hvac system and might keep my dehumidifier from running so much.

[Guest 70below]

When I was a contractor I dealt with leaky basement walls like yours several times. Obviously the best solution is to dig behind the wall and put drains in to prevent hydraulic pressure from building behind the wall when it rains.

Drylok is great stuff, but first you need to put a hydraulic cement on your wall to seal up any places that seep. There are lots of different brands on the market, but I recommend one that has fiberglass in it so it holds up over time. Mix it and spread it about 1/4" thick on the wall with a trowel, you can do it kind like stucco or smooth, or even texture it with a broom if you want.

Then, I put drylok over that just for extra protection or to prime it for paint.

Expanding foam is great stuff, and most kinds won't absorb water, but you need to do all you can to prevent moisture issues before you use it. Make sure that the area is completely dry before you use it to ensure you don't trap moisture in where it can cause decay or corrosion.