Foam Insulation Under Cab for heat??
Hello Campers! Took my RV to a local HIGHLY recommended shop to get their opinion about the poor airflow in my 2007 Ford E450 Winnie Outlook. He said that he has seen rigs come in with Spray Insulatio...
Forum Discussion
Hi,
My buddy has a 1987 Ford based class C, and it also has foam applied to the underside of the Box portion of the RV. Not under the cab itself.
As long as you stay about 3" from the exhaust, then spraying on the foam to the cleaned sheet metal should work find. You need to prep it properly, according to the material being applied. In other words, if they say to not using rubbing alcohol to prep the metal, don't use it. If they say must be cleaned with rubbing alcohol, then that is the stuff to use, and the foam is compatible with it.
They do make higher than average temp rated foams, used to fireproof buildings, but still it might not hold up well next to the 1,100 F exhaust system, so check the ratings on the products. You might also consider wrapping a small section of the exhaust system, where it is closest to the chassis metal, and also the doghouse. This will reduce the amount of heat radiated into the drivers area.
My buddy replaced the factory fiberglass insulation with some cheap foam aluminized insulation - it did not work worth a darn, still transmitted more heat than the factory insulation, and caught fire while driving in 95F weather on the way to Las Vegas. So we tore that out, and went without insulation until I replaced it with some 1.5" thick air duct insulation. I don't know how fireproof it is, but it is rated to not promote flame spread, and putting a BBQ lighter to the fiberglass for about 30 seconds did no damage to the material. So it has been in place for about 6 years now, with no damage yet.
I put some 1/2" thick foam pads on the floor of my RV, and it really helped cut down on the heat transfer into my class A motorhome.
Fred.
My buddy has a 1987 Ford based class C, and it also has foam applied to the underside of the Box portion of the RV. Not under the cab itself.
As long as you stay about 3" from the exhaust, then spraying on the foam to the cleaned sheet metal should work find. You need to prep it properly, according to the material being applied. In other words, if they say to not using rubbing alcohol to prep the metal, don't use it. If they say must be cleaned with rubbing alcohol, then that is the stuff to use, and the foam is compatible with it.
They do make higher than average temp rated foams, used to fireproof buildings, but still it might not hold up well next to the 1,100 F exhaust system, so check the ratings on the products. You might also consider wrapping a small section of the exhaust system, where it is closest to the chassis metal, and also the doghouse. This will reduce the amount of heat radiated into the drivers area.
My buddy replaced the factory fiberglass insulation with some cheap foam aluminized insulation - it did not work worth a darn, still transmitted more heat than the factory insulation, and caught fire while driving in 95F weather on the way to Las Vegas. So we tore that out, and went without insulation until I replaced it with some 1.5" thick air duct insulation. I don't know how fireproof it is, but it is rated to not promote flame spread, and putting a BBQ lighter to the fiberglass for about 30 seconds did no damage to the material. So it has been in place for about 6 years now, with no damage yet.
I put some 1/2" thick foam pads on the floor of my RV, and it really helped cut down on the heat transfer into my class A motorhome.
Fred.
