Spar Thickness

[Diemjoe]

I was wondering how much trailer width affected the thickness of the Spars. I was thinking of glueing 2 pieces of 3/4 plywood That are 2 inches wide to match the insulation thickness. Trailer is just shy of 5' wide. Wall are 3/4" skeleton with 1/4" skins on both sides.

[aggie79]

I used single 1x2s on edge (1-1/2" x 3/4"). Spacing was 16" o.c. except at vent fan. I also double up the vent fan spars to allow "meat" for the fan fasteners. In the curves, the spar spacing was tighter.

[Diemjoe]

I used single 1x2s on edge (1-1/2" x 3/4"). Spacing was 16" o.c. except at vent fan. I also double up the vent fan spars to allow "meat" for the fan fasteners. In the curves, the spar spacing was tighter.

What type of wood were your 1x2's?

[angib]

I was thinking of glueing 2 pieces of 3/4 plywood That are 2 inches wide to match the insulation thickness.

Remember that only half the plies in the plywood will run from one side to the other - the rest will run up and down and provide no extra strength. A decent 1x2 would be as strong.

[Jdw2717]

I ripped 2x4x8s in half to get the spars at 1.5"thickness for double foam isulation layers. Any water intrusion will not cause the weakness that delamination would bring if water ever got inside the structure. Install with any existing bow facing up. I believe plywood would be a little heavier also.

[coyote]

I to ripped 2x4s and used them. ( too long working on caterpillars, I put them every 8 inches front to galley, slight overkill I think) coyote

[jonw]

Poplar 1x2s on edge worked well for me

[aggie79]

I used single 1x2s on edge (1-1/2" x 3/4"). Spacing was 16" o.c. except at vent fan. I also double up the vent fan spars to allow "meat" for the fan fasteners. In the curves, the spar spacing was tighter.

What type of wood were your 1x2's?

Poplar. The big orange and blue box stores usually carry poplar. Pine will work too but you need to be careful with using screws. You can over-torque screws more easily in pine.

[Diemjoe]

Thanks everyone. I am going to go out and get Poplar this weekend then.