Open Cell vs Closed Cell spray foam insulation

[MRollins10]

So i already googled this, but still kinda unclear, so i thought i would post it out on the board for your opinions.

The spray foam guy is here today for my barn. He suggest spraying closed cell foam into the large shop area. For the 15x30 mother in law unit that is going to be later framed out, he suggested doing that in open cell foam. Is this the right way to go?

 

[EddieWalker]

Open cell is cheaper, has a lower R value and it holds moisture. If sprayed against metal, it might void the warrantee from the metal company because over time the moisture in it builds up and rusts the metal.

Closed cell is more expensive, it has a higher R value and moisture cannot get into it. It's used for floating docks.

I went with a client of mine to look at a $800,000 house for sale that she was considering buying. It was a really nice house and priced below market for the area. The realtor said they where getting a divorce and wanted a quick sale. My first impression was that it was going to need a new roof fairly soon, which didn't make sense since the house was only a few years old. Looked like hail damage with so much of the rock coming off of the shingles and already starting to curl up. In the attic I found open cell sprayed to the roof. I believe that is why they are trying to sell the house at a lower price, because it's destroying the roof and it's going to have to all come out and then new decking and shingles installed.

I did a search online to see if it could be anything else and found conflicting reports. Some say it's OK, but there has to be a barrier to keep the foam from touching the decking and lumber that makes up the roof structure. There where also a lot of lawsuits about the damage open cell has caused in homes.

When I spoke to the guys at Muellers, where I buy my metal roofing, they said to never used open cell foam if it touches the metal. For me, that's all I needed to hear.

I've been told by other contractors and even one insulation guy that it's ok to use open cell, that it's blamed for things that where the roofers fault, or just people trying to sue for no reason. I don't believe them and will never use open cell foam.

Call your metal supplier and talk to them. If your metal rusts on you in a few years, or even ten years, will they do anything about it if you used open cell foam? Be sure to get it in writing if they say it's ok to use open cell foam!!!!

 

[Diggin It]

Personally, I can't see using anything that can't be removed fairly easily. FG Batting, rigid foam panels and cellulose may be miserable to work with, but they can be removed if wall/roof/floor access is needed. Spray in foam has to be cut out and you may not be able to get it all, no matter how hard you try.

FG batting, rigid foam panels and cellulose can be reinstalled also where foam cannot.

 

[MRollins10]

Open cell is cheaper, has a lower R value and it holds moisture. If sprayed against metal, it might void the warrantee from the metal company because over time the moisture in it builds up and rusts the metal.

Closed cell is more expensive, it has a higher R value and moisture cannot get into it. It's used for floating docks.

I went with a client of mine to look at a $800,000 house for sale that she was considering buying. It was a really nice house and priced below market for the area. The realtor said they where getting a divorce and wanted a quick sale. My first impression was that it was going to need a new roof fairly soon, which didn't make sense since the house was only a few years old. Looked like hail damage with so much of the rock coming off of the shingles and already starting to curl up. In the attic I found open cell sprayed to the roof. I believe that is why they are trying to sell the house at a lower price, because it's destroying the roof and it's going to have to all come out and then new decking and shingles installed.

I did a search online to see if it could be anything else and found conflicting reports. Some say it's OK, but there has to be a barrier to keep the foam from touching the decking and lumber that makes up the roof structure. There where also a lot of lawsuits about the damage open cell has caused in homes.

When I spoke to the guys at Muellers, where I buy my metal roofing, they said to never used open cell foam if it touches the metal. For me, that's all I needed to hear.

I've been told by other contractors and even one insulation guy that it's ok to use open cell, that it's blamed for things that where the roofers fault, or just people trying to sue for no reason. I don't believe them and will never use open cell foam.

Call your metal supplier and talk to them. If your metal rusts on you in a few years, or even ten years, will they do anything about it if you used open cell foam? Be sure to get it in writing if they say it's ok to use open cell foam!!!!

Yeah, i keep finding conflicting results too. I did call my metal provider. They said that it wouldnt void their warranty. Which makes me feel a bit better. I hate that i cant get a DEFINITIVE answer from researching it.

 

[davedj1]

Just go with closed cell.

 

[Rustyiron]

Closed cell.
I've seen a 2" layer of closed cell against the outside for your moisture barrier and better r value, then the cavity filled with open. From what it seems to me is that they came up with it to sell more foam, just at a lower performance and price. At that point I'd spray 2" of closed cell for its insulating and air seal qualities, then fill the stud bays with f/g batts. With no air movement in the stud bays (because of the cc s/f) the f/g batts will perform up to its rated r values.

 

[johncanfield]

Closed cell foam has structural properties and as others have mentioned is impervious to moisture . However a house needs to breathe, visit the Build channel on YouTube for more background. We have open cell foam sprayed on the inside of roof decking on our house addition and our new detached car garage.

 

[goeduck]

Closed cell is more expensive, it has a higher R value and moisture cannot get into it. It's used for floating docks.

Very true, my closed foam floats have been in the saltwater since 1994 and are still doing their job. Every flood tide in, every ebb tide out.

 

[EddieWalker]

Personally, I can't see using anything that can't be removed fairly easily. FG Batting, rigid foam panels and cellulose may be miserable to work with, but they can be removed if wall/roof/floor access is needed. Spray in foam has to be cut out and you may not be able to get it all, no matter how hard you try.

FG batting, rigid foam panels and cellulose can be reinstalled also where foam cannot.

Since the foam isn't installed until all the electrical and plumbing are done, there really isn't too much of an issue dealing with what might happen years down the road after the sheetrock is up and painted. If for some reason the foam has to be cut out, it's super easy to do with a sheetrock hand saw. It cuts like butter. Then you can put it back in place, or just spray in new foam from a can. Either way, it's pretty simple.

 

[EddieWalker]

Yeah, i keep finding conflicting results too. I did call my metal provider. They said that it wouldnt void their warranty. Which makes me feel a bit better. I hate that i cant get a DEFINITIVE answer from researching it.

One of the biggest roofing companies out there also sells open cell spray foam. I think it's Certanteed, but didn't double check that before writing this. In their instructions, they talk about sealing or having a barrier between the open cell foam and the wood that it's sprayed to. Other roofing suppliers will void their warrantee if open cell foam is used. I believe this is why it's so hard to find a definitive answer on using open cell foam. Taking the time to look up every possible search question to find the answer takes forever, and for every lawsuit that you find caused by open cell, you'll find where it's been used and it's just fine. What I came away with was that there where no lawsuits or complaints from anybody using closed cell foam. The open cell spray foam has everything said about it from being fantastic, to destroying roofs. I would never use it under any condition for anything that I own, and when asked about it by my clients, I tell them to avoid it.