Securing the roof

[Forrest747]

I have question about securing the roof. I plan on putting a bead of PL adhesive along the spars and wall joints. The spars are about every 12 inches or so. The roof is also flat from the front to the back. So i was wondering can I just screw it around the perimeter where the walls meet the roof. the roof will be 3/4 inch

[jonw]

I have question about securing the roof. I plan on putting a bead of PL adhesive along the spars and wall joints. The spars are about every 12 inches or so. The roof is also flat from the front to the back. So i was wondering can I just screw it around the perimeter where the walls meet the roof. the roof will be 3/4 inch

That's basically what I did on mine, although my roof is just a sheet of aluminum. Just figure out a mechanism for clamping/pressing the roof to the spars until the glue dries.

I used wedges underneath bar clamps. Another method is to use a few screws to hold it down and then remove and fill in the screw holes (or just leave them in depending upon what look you are going for). The only issue with this method is the potential for introducing leaks.

Good luck!

[afreegreek]

that will work fine but you're better off putting some fasteners along your "spars" too at least until your adhesive cures.. after, you can take all the fasteners out if you want to as long as you got everything positioned before the adhesive skinned over.. a good bead of PL is 10x more than you need and the screws serve no purpose other than attracting moisture..

[afreegreek]

The only issue with this method is the potential for introducing leaks.

Good luck!

there is no leak issue if the screws or pilot hole don't penetrate all the way through the spars..

[absolutsnwbrdr]

I'm sure I overbuilt mine... but for my 1/4" plwood skins, I used 3/4" screws all over the place. Just countersunk them a hair into the 1/4" ply, and puttied over them.

Since your roof isn't curved, I'm sure the construction adhesive would probably be fine alone, but why not throw a few short screws in just to be sure. Just think of it as extra insurance IF you happened to get a bad batch of adhesive. (I know, not likely)

[aggie79]

that will work fine but you're better off putting some fasteners along your "spars" too at least until your adhesive cures.. after, you can take all the fasteners out if you want to as long as you got everything positioned before the adhesive skinned over.. a good bead of PL is 10x more than you need and the screws serve no purpose other than attracting moisture..

That is how I fastened my 1/8" ply roof. For the screws, I used the self-drilling screws so I didn't have to drill pilot holes. The screws didn't fully penetrate the spars.

Since I was covering the roof (and sidewalls) with aluminum, I found it handy to mark the location of the spars and electrical runs on the plywood so I didn't put any fasteners where they didn't need to be.



After the PL Premium set, I removed the screws, and filled the holes.

Take care,
Tom

[dano]

Forrest747,

Cant help with the roof but love profile of your rig.
Cant wait to see it when its done.

[afreegreek]

that will work fine but you're better off putting some fasteners along your "spars" too at least until your adhesive cures.. after, you can take all the fasteners out if you want to as long as you got everything positioned before the adhesive skinned over.. a good bead of PL is 10x more than you need and the screws serve no purpose other than attracting moisture..

That is how I fastened my 1/8" ply roof. For the screws, I used the self-drilling screws so I didn't have to drill pilot holes. The screws didn't fully penetrate the spars.

Since I was covering the roof (and sidewalls) with aluminum, I found it handy to mark the location of the spars and electrical runs on the plywood so I didn't put any fasteners where they didn't need to be.



After the PL Premium set, I removed the screws, and filled the holes.

Take care,
Tom

yup, that's the way to do it.. the extra battens are good.. they keep things in plane.. PL is thick and it's pretty easy to create undulations in the skin with screws alone.. self tapping screws are good, those look like TAPCON, but drywall screws well. they're designed to penetrate softwood lumber with no pre-drill and the shanks are thin with raised thread to prevent 'bridging'.. they're also very cheap.

[planovet]

I used staples to hold it until the glue dried. It was a lot faster than using screws and I just used epoxy filler to cover them up.

[H-Balm]

I agree with the others.... you will ant to fasten down the roof at multiple points, not just the edges.

Wood can have very slight warps to it, and you would run the risk of having sections that may not bond fully with your adhesive. Even if you decide not to use deep, structural screws, it would be wise to use smaller, temporary ones to hold it down until the adhesive has set.

You will be using some sort of sealant at the joints, so applying very small areas where your screw holes are really isn't that big a deal.

Good luck.