Fixing down t and g OSB3

[Ollie78]

I am part way through building a carport, frame is up and joists on. Next time we get a break in the weather for a couple of days I want to put the roof on.
We have elected to use fibreglass for reasons of cost, ease of use and aesthetics, considered rubber but that is a very large bit of heavy stuff to manipulate on my own (9m x 7m).

So to the point, I will be fixing 40 odd sheets of T & G OSB.
Some advice is to screw it, some say nail it.

Screwing is going to be a lot slower than a nailgun but I do not have access to a roofing style coil nailer for full head nails.
I might be able to borrow a framing nailer (or might buy one if cheap enough) but these will only fire clipped head nails as far as I know.
Will a 65mm ring shank with clipped head be fine for this job ?

Ollie

 

[Sideways]

I screwed the OSB3 down when reroofing a single garage.
Whoever has to lift the boards will surely curse me for that, but it makes a stong roof and didn't take long. Spax wirox and a 18v drill driver .... Torx heads so you just dial in the drill and let it work. The slow bit is just setting out the chalk lines to make sure you are centred on the joist and screws evenly spaced.
In winter, you can see where all the metal screw heads are under the rubber because the frost melts off there last.

 

[Bingy man]

I would also use screws rather than nails . It’s easier later down the line if you need to make alterations or need to carry out any repairs doesn’t take that long as @Sideways says above once it’s all set up .

 

[Ollie78]

I would also use screws rather than nails . It’s easier later down the line if you need to make alterations or need to carry out any repairs doesn’t take that long as @Sideways says above once it’s all set up .

Not sure we will ever be able to get to the screws or nails again bacause they will be under fibreglass. I am just not relishing putting in so many screws. Nailguns seem so quick.
Any particular screw best for this? I guess it needs to have a clearance on the shank with no thread for the top 20mm or so.

 

[HOJ]

My preference would be nails, its not designed for coming off in a hurry with fibreglass over it, but in my case I have the option of various nail guns to hand, again personally I'd use 51mm Ring shank nails, 65mm is a bit much, but if that's what you have.

IIRC the spacing's should be @ 300mm, I can buy a box of 3300 nails for £38.14 where as decent wood screws are about £10.00/200.

 

[Bingy man]

Not sure we will ever be able to get to the screws or nails again bacause they will be under fibreglass. I am just not relishing putting in so many screws. Nailguns seem so quick.
Any particular screw best for this? I guess it needs to have a clearance on the shank with no thread for the top 20mm or so.

Anything with a torx head as they are much easier to drive in and less likely to cam out like pozidrive or Philips head screws . As above 50mm would give you approximately 30 mm into your joists . I miss understood when you said fibreglass as pre formed fibreglass sheets and not the flat roofing system that’s used instead of felt and bitumen..

 

[Fergie 307]

One of the worst jobs I ever got involved in was to help a neighbour redo his shed roof. OSB held down with long ringfast nails, absolute pigs to get out.

 

[Ollie78]

Anything with a torx head as they are much easier to drive in and less likely to cam out like pozidrive or Philips head screws . As above 50mm would give you approximately 30 mm into your joists . I miss understood when you said fibreglass as pre formed fibreglass sheets and not the flat roofing system that’s used instead of felt and bitumen..

I had a bunch of torx head screws but actually found them worse for cam out and they were very easy to damage if you didn`t have them perfectly straight. maybe they were just rubbish ones, I bought a load in all sizes, ended up giving them away. Saying that I dont mind the torx heads onthe tongue tite screws so maybe there are better ones now.

My preference would be nails, its not designed for coming off in a hurry with fibreglass over it, but in my case I have the option of various nail guns to hand, again personally I'd use 51mm Ring shank nails, 65mm is a bit much, but if that's what you have.

IIRC the spacing's should be @ 300mm, I can buy a box of 3300 nails for £38.14 where as decent wood screws are about £10.00/200.

I had also thought about cost and the nails definitely win on that point, so do you think a clipped head is fine ?

 

[Bingy man]

I had a bunch of torx head screws but actually found them worse for cam out and they were very easy to damage if you didn`t have them perfectly straight. maybe they were just rubbish ones, I bought a load in all sizes, ended up giving them away. Saying that I dont mind the torx heads onthe tongue tite screws so maybe there are better ones now.

I had also thought about cost and the nails definitely win on that point, so do you think a clipped head is fine ?

Quality screws and quality bits - I currently use forgefast ( Toolstation) and have not had any issue’s with any of the sizes- no 4 upto no 6 ..