How far apart did you put your roof spars?

[misterW]

1 foot? sixteen inches? two feet? My trailer is 5x12, so I was wondering if more spars for extra strength might be in order.

[aggie79]

I used 1x2 poplar on edge for spars. Spacing was 12" on center except for:

1. My profile has curved sections and straight sections. I added spars at the points where the curves began at the straight sections.
2. In the tighter radius curves I put additional spars - about 6" o.c. - to help the plywood bend around the curve.
3. I used 5'x5' plywood. Where the plywoods sheets join, I doubled up the spars there to allow for better fastening/gluing.
4. At the vent fan, I used doubled up the spars and spaced them to fit for the vent fan.
5. At the header for the hatch hinge, I doubled up the spars.

[Arne]

12" because I used 1/8" luan ply inside and out.

[planovet]

About 12" on the straighter parts and 8" on the curvier parts.

[afreegreek]

you could put them in temporarily and remove them after your roof is on.. all you need to do is laminate three layers of 1/8" together in place.. since 1/8" is not really 1/8" thick, what you'll end up with in 9 plies @ about 5/16"

[mikeschn]

About 12" on the straighter parts and 8" on the curvier parts.

That sounds about right...

Mike...

[kennyrayandersen]

you could put them in temporarily and remove them after your roof is on.. all you need to do is laminate three layers of 1/8" together in place.. since 1/8" is not really 1/8" thick, what you'll end up with in 9 plies @ about 5/16"

I’m not sure why you would need 3 layers of 1/8. I’m thinking at most 2 layers, but for most small builds even one is enough – plenty have people have built that way and I don’t see any of them having ‘structural’ problems.

[48Rob]

Mister,

Mine are on 12" centers, for a 78" span.
I used 1 x 2 Oak, vertical spars, with spacer/ties between several of them for more strength.
I have 2 layers of 1/8" ply laminated together attached to the spars.
I'm 185 pounds, and I can walk on the roof easily when my weight is on the spars, and very carefully when on just the plywood.

For yours, it depends...

What thickness roof will you use?
What material will the roof be?
What dimension will the spars be?
What material will the spars be?
How much weight do you want the finished roof to be able to support?

Rob

[asianflava]

I used 1x2 poplar on edge for spars. Spacing was 12" on center

Me too, I guess it's the poplar choice?