Roof material for queen width

[calumet]

I am using ½” solid walls that I will later insulate and panel. I am assuming the insulation and paneling will take 7/8” (¾” + 1/8”) which I’ll round up to 1”. Should the floor width between the two ½” solid walls then be 62” for a queen (60”) mattress or is this too tight of a fit?

Then, the real question:
5’ plywood is not available to me but would not be 62” anyway. I don’t see any problem with turning 1/8 ply sideways for the headliner making sure the joints land on a ceiling joist but the actual roof skin would then have seems. So, what would be the easiest, cheapest, lightest, most readily available material for the roof.

[GregB]

I used 1/4" Aquatek waterproof 4x8 plywood for mine and it is 65" wide. I managed to find some use for the 31" cutoffs. Seams were sealed using Fill-it from Rot Doctor.

GB

[b.bodemer]

I turned my 1/4" birch sideways and had no trouble.



I also have a queen mattress, made of memory and high density foam, and I've got exactly 60" space for the 60" wide mattress.


Barb

[calumet]

Great! Thanks!
Looks like plywood seams are ok if sealed properly. I’ll try to find the Rot Dr. Fill-it.

[Esteban]

I will, soon, be using epoxy and 6 oz. fiberglass cloth from raka.com to cover two layers of 1/8" plywood on the roof. The tear drop will be painted with epoxy boat paint for UV protection and looks.

The outside of the cabin will be 63" wide. A queen sized foam bed will fit inside.

Extra lighting to meet DOT requirements for an over 80" wide trailer is an extra expense and unanticipated complication to build this wide. The outside fender to fender width will be about 85" wide.

[GregB]

BTW, if you are really concerned about seams leaking, lap 'em. I lapped a couple of seams over 3", but found it is a pain trying to plane 1/4" ply down to 1/8" consistently. Another option is to use two layers of 1/8" ply and stagger your seams.

GB

[Reddiver]

I am probably going to use bendable 1/8 poplar ply . Do you think it is necessary to put two layers of 1/8 ?

[GregB]

Reddiver,

Typically, no, many people put one layer of 1/8" ply on their roof. The strength, comes from the curve into which it is bent. If you are using bendy ply in a 5' wide, though, your spars may need to be closer together. Some on the forum have noticed that it sags more than traditional ply.

GB

[Reddiver]

I put the spars 14in apart guess I could put one in the middle at least on top where it is kind of flat.
Thanks