Spray foam for travel trailer ceiling and walls?

But you will definitely regain strength. That foam is absolutely strong stuff. And seals as well.

RinconVTR wrote:

72cougarxr7 wrote:

RinconVTR wrote:
I will provide another perspective. What's to gain by making the repair with spray foam at a professional level repair?

Strength is not part of this, as any repair will not regain or add any strength from what was originally in place. Insulation R value? May be.

Look at the other features of your TT. Windows and underbody for example. Do you reall think this small area of repair with or without insulation will make any difference? Odds are...no.

Make the repair, use a can of low expanding foam in a can for $4, or pack the are with fiberglass. And be done. You, nor anyone else will know the difference.

I am talking about my entire ceiling and back wall, I would imagine having that all insulated would make a substantial difference in my trailers indoor temps, especially in the summer with the sun beating down on my hot tin roof!

Well, I guess I underestimated what you were really doing.

My reply, surprisingly doesn't change.

Its a trailer...I think think high R-values do not outweigh the excessive cost (or effort) unless you live in it year round AND all other features of the trailer are also of high R-value.

The OP is going to put some sort of insulation back in the spaces he opens or has opened.

If the original fiberglass bat insulation is deemed to be failing (and I've seen what happens) what would you suggest to put in those spaces?

72cougarxr7 wrote:

RinconVTR wrote:
I will provide another perspective. What's to gain by making the repair with spray foam at a professional level repair?

Strength is not part of this, as any repair will not regain or add any strength from what was originally in place. Insulation R value? May be.

Look at the other features of your TT. Windows and underbody for example. Do you reall think this small area of repair with or without insulation will make any difference? Odds are...no.

Make the repair, use a can of low expanding foam in a can for $4, or pack the are with fiberglass. And be done. You, nor anyone else will know the difference.

I am talking about my entire ceiling and back wall, I would imagine having that all insulated would make a substantial difference in my trailers indoor temps, especially in the summer with the sun beating down on my hot tin roof!

Well, I guess I underestimated what you were really doing.

My reply, surprisingly doesn't change.

Its a trailer...I think think high R-values do not outweigh the excessive cost (or effort) unless you live in it year round AND all other features of the trailer are also of high R-value.

72cougarxr7 wrote:

I have been considering pulling the rest of the ceiling down (already have 1/2 pulled out) and having a spray foam contractor spray the whole ceiling and rear wall.

You might also want to check out DIY spray foam kits. There are quite a few vendors out there, and you get everything you need to get the job done. Most have calculators on their sites so you know how much you'll need based on the coverage area and depth of foam.

I have a small walk-in wine cellar that I'm building (5'6" x 11' x 7'6" tall) and that's how I'm insulating it. It's much cheaper to do it myself since it's a small area. There's an added benefit of spray foam as well: it acts as its own vapor barrier! :)

As a guy who has spent his life working with houses I'll be the one naysayer to the idea. I see spray foam trickling into residential and commercial construction and I'm not a fan.

Yes, all of the things everyone says about it are true. It generally works better from a performance perspective. The downside is the inability to work with/around it later. You get another roof leak? First off you probably won't notice it until it's caused substantial damage since the foam will soak it up and potentially channel the water down the side walls (more damage). Then, when you go to make a repair it is a total PITA.

Maybe I'm just an old dog but well installed bat insulation and/or rigid foam will be 90% as good without the initial expense or potential headaches down the road.

72cougarxr7 wrote:

You guys have given me alot of info to think over.

To repeat a couple of cautions:

If you do foam you MUST either under-fill a bit OR cut the overfills down before you apply the inside wall coverings. Cutting it down is not as easy as you might think.

If you are putting foam into an enclosed void, you must use the minimal expanding type and it is a good idea to have a couple of vent holes too. The foam expanding inside a closed space can exert a significant force and sometimes rip the paneling or drywall right off the wall.

IMO, those retail DIY Spray Foam kits (like Tiger foam or other foam kits bought from hardware retail stores) are over diluted and lower quality compared to professional Spray Foam type. Use Closed Cell / 2 lbs (aka Medium desity) outside and inside RV/TTs. For that size of location and road vibrations, I'd only get professional grade foam applied.

Being a RV/TT, you can do all the prep work yourself. And, apply any structure repairs / reinforcements yourself as well. And if wiring (like Roof Top AC units) areas are involved, you can install your own Electrical PVC piping as well. Thus, create a wire fish zone (just in case you need to change future electrical wiring) improvements as well. Prep it all, then take your RV/TT to the foaming company's location. They spray your rig when they spray others. Thus, saving on "their" travel and job Prep-Work costs as well. Thus, lower final estimate for them.

If wondering, I did my own prep work (took me 4 weeks) and got my previous Jayco's underbelly professionally sprayed (by a mobile professional company) as well. One of the best mods we did for our previous 29 ft TT. And yes, I'd do it again - without hesitation. Contractor Grade is amazing stuff. Especially for small areas - like RV/TTs and you plan to keep your TT for 5+ years. re: - click here -

Hope this helps.

My opinion, if you're going to do all that prep work yourself, do the spray yourself. The biggest part of the job is the prep. That's what really goes into the cost. But I doubt a pro would just come in and spray very cheaply. He's still gonna want to make his money.

You can rent the spray guns and air compressor at a hardware rental shop. Probably sell the medium as well, but if not, any big box hardware store will have it.

The OP states the roof was leaking around an antenna, not through the whole roof. A complete new roof is expensive and,IMO, the older sheet aluminum roofs are superior to EPDM covered roofs.
The essence I'm getting from the posts by the OP is that he hopes to get the cabin temperatures lowered in the summer and to replace the poor insulation job in the back wall where he has to open it up anyway. Any insulation material is going to be towards the hopes of the OP. Spray will be the best R-value and the most expense. Extruded polystyrene will be close to spray in R-value, less cost but more work. Fiberglass or Roxul will be the least expensive but the lowest R-value.
One thing to consider is the dimensions of the spaces involved. There is not that much difference in a 1 1/2" wall if filled with the best or worst insulation. The ceiling cavity with the larger space and exposure to direct sunlight will benefit the most from the best insulation.

I think that if you are going to spend all this time and money on spray insulation in the ceiling you might as well pull the entire roof off the trailer and go all the way. This way you can get rid of any water damaged wood and install all the ceiling panels properly giving a factory look. Insulating will be a breeze from the top. You can also get rid of the problematic metal roof (maybe get a few $$ for the scrap metal) and install new EPDM or maybe rhinoline it....

OK enough sarcasm... just repair what needs repairing without going overboard, and go have fun in it... That is what RVing is all about..