Insulating underneath the floor??

[Alfred]

Hi Gang,

Here's the picture - Whats my best option for insulating underneath this 1/2" ply floor?? Do I really need the insulation? I noticed another post suggested cutting insulation with a table saw, I don't have a table saw yet, but I do have a hand skill saw also a hand jig saw.








Thanks, AL in Asheville

[madjack]

Al, my suggestion would be to get some"blue" insulation board from the box stores and place it INSIDE, under the mattress...this what I have done...why you ask...the one thing you don't want to do is place anything that can form a water trap against the wood which would promote rot...by placing it on the inside, you eliminate this problem, don't havvta worry about a fastening/mounting system and protect the insulation from damage from road debris...I didn't feel the need for floor insulation since there was 6"s of foam mattress above the floor but after a cold weather camping trip, I noticed some dampness from condensation under the edge of the mattress...by the way, I have 1/2" ply floor as well...................
madjack
p.s. cutting the insul with a table saw is kinda like using a sledgehammer to kill an ant...use a razor/mat knife and a straight edge to score it and then, if needed, snap it in two........MJ

[Alfred]

Hi Jack -

This sounds reasonable. Do I fasten it down on the inside? Do I put anything between the mattress and the insulation, or just put the mattress right on top of the insulation board?

AL.

[starleen2]

Hi Jack -

This sounds reasonable. Do I fasten it down on the inside? Do I put anything between the mattress and the insulation, or just put the mattress right on top of the insulation board?

AL.

Really no need to fasten it down, the weight of the matress will hold it place. You should be OK to place the mattress directly on top of the foam.

[madjack]

Hi Jack -

This sounds reasonable. Do I fasten it down on the inside? Do I put anything between the mattress and the insulation, or just put the mattress right on top of the insulation board?

AL.

Really no need to fasten it down, the weight of the matress will hold it place. You should be OK to place the mattress directly on top of the foam.

...yep...yep...AND yep .................................................

[Alfred]

Thanks for the advice - Y'all are awesome!

AL.

[bobhenry]

I built over my wheels and wound up with these little bumps



to eliminate them I put down 2 layers of 3/4 blue foam on the floor around them them added a 7/16 osb floor over the foam. Went underneath and sealed with aerosol spray on bed liner to waterproof for the road spray.

We have been out twice at -15 wind chills ( cause we're crazy) and I am real glad we insulated. As jack says inside because it stays dry and no water or condensation problem.

[kennyrayandersen]

I wouldn't do it that way because you'd be eating up interior volume, which is already in short supply. 2 inches doesn't sound like much, but my wife's already claustrophobic. I'd use the 2 inch stuff, put it on the bottom in the holes and cover the bottom with 1.8 inch ply that is sealed around the edges so that water doesn't get in and on the bottom with the black stuff that you have already developed a talent for.

If losing the volume doesn't bother you, then putting it underneath the mattress is certainly easier.

Either way will work.

[xrover]

What about using a spray on underneath? I don't mean the crack filler stuff, but the proper spray on they use for buildings? I had it done under our cottage and it's great stuff, no moisture traps, no way for bugs to get in behind it, and it's tough and durable.
I think there are some home kits you can buy however I don't know the brand names etc. Others here are more knowledgeable on this.

[Alfred]

Hi Gang,

When I was researching this question last night I came across another thread about spray-on insulation. Seemed an interesting alternative. There was an issue about the foam expanding, if I was reading it correctly, so that this needs to be allowed for.

AL.

[bobhenry]

If losing the volume doesn't bother you, then putting it underneath the mattress is certainly easier.

Either way will work.

I wired mine setting inside in my camp chair its 5'4" inside so volume was not an issue. As to claustraphobia this was my answer.............

[kennyrayandersen]

Yeah you got you some extra tall tear -- not every one's going to be that tall. I've always liked the see-the-stars roof, but down TX way that would be identical to a solar oven and we'd get fricasseed! Plus, I ain't got no frame, so I think I need the roof for extra structure (plus it will be insulated for the heat)

[Boodro]

Just a thought ,, I used those rubber shop mats that fit together like a big jig saw puzzle. They are very cheap & tough. It insulates the floor & makes the floor easy to kneel on when your mattress is not in the tear. They come in black or different colors too. Very easy to install ! Good luck!

[Arne]

you can insulate the floor for less than 50 bucks... it will work for you forever.

I did not insulate the floor on no. 1 and wound up with little puddles of condensed breath at the corners of the mattress where my head is.

no. 2 has an insulated floor.

[studebiker]

Hi,
I'm a newby and still in the designing phase for my own TD, but a friend of mine built one a couple of years ago and he used foam backed insulated berber type carpeting on the inside. So far no problems, he says. For the water proofing under the floor he used a neoprene pond liner and used contact cement to apply it to the under side of the floor. He did not use a wooden frame since his steel frame is already pretty beefy. I thought the pond liner idea was awesome. What do you all think?