How to secure a hardwood ply roof to a workshop?

[ironbark]

Hi I'm building a large workshop/studio under a very large shed. The studwork is up and the ceiling/roof rafters ( 140mmx45mm) are in place. This structure has a racked roof and it's completely protected from the weather. I have all the sheets of 12mm ply that I need. I am intending to glue and possibly nail the ply into position (leaving a small expansion gap between sheets that will be laid in a 'stretcher bond' style. I have a Paslode Frame-master nail gun and was intending to use 50mm nails. I'm now wondering if screws along the edges might be wise; and if so what size and type would be best?

Any comments or suggestions would be much appreciated.

Thanks John

[MitchellMc]

Hi John (@ironbark),

I take it these plywood boards are for internal cladding of the walls? If so, I can't imagine the sheets are going to go anywhere if they are glued and nailed into place. Was there anything you were particularly concerned about?

There's nothing wrong with using screws instead, and I'd suggest something along the lines of Zenith 8 - 10 x 40mm Treated Pine Countersunk Head Screws. That's presuming you've used exterior grade timber. If not, you can use any screw in those sizes.

We'd love to see some pictures of your build if you'd care to share them

Please let me know if you have any questions.

Mitchell

[ironbark]

Hi Mitchell,

Appreciate your reply. No, the sheets of plywood are for the roof. Once fitted they will have a few coats of exterior paint. This whole structure is under the cover of a much larger shed and so unless a cyclone blows off the shed roof this structure's roof will remain totally out of the rain. The shed is open sided so we will get any wind that blows through but having said that the site is well protected.

The structure is to be used as a workshop & pottery. Unfortunately the camera on my phone has packed up otherwise I could upload some images. Maybe I can borrow a camera. I'll plasterboard the inside walls and use corrugated sheets externally.

Yes my main concern was whether screws might be less likely to damage the edges than using the 50mm nails via the nail-gun (I'd obviously minimise the power on the nail-gun ?

Any advice will be much appreciated.

Cheers John

[EricL]

Hello @ironbark

Just to add to the fantastic advice that @MitchellMc has already given you. Using the Zenith 8 - 10 x 40mm Treated Pine Countersunk Head Screws - 100 Pack is likely to give you a better finish than using the nail gun. If you want to have a flat finish, I suggest using a Countersink Drill Bit to drill pilot holes. It will give it that nice professional finish and will prevent pinching the top of the timber.

If you need further assistance, please let us know.

Eric

[MitchellMc]

I apologise, @ironbark. You did mention in the title that the sheets were for the roof. 

I agree with @EricL that screws would cause less damage along the edges. Pre-drilling will also assist with the timber not splitting. 

Mitchell