Door canopy roof: do I need battens? Is plywood ok?

[lozcozard]

I’ve built that attached door canopy.

Roof is next but I can’t find much info/help online for such such a roof so wondered if anyone here can help…

I thought I’d just plywood or OSB it first then nail slate tiles to that. Would that be ok?

or do I need battens to hang the tiles on?

If I need battens do I need the plywood? Could the battens just run across the rafters?

Will tiles stop 100% water or not? If not I guess the plywood would help but I’d need to cover it with some waterproof sheeting?

thanks a lot

 

[Alastairreid]

Felt/membrane and battens for sure, osb, ply to prevent wind lift in an open structure.

 

[lozcozard]

Oh yes I didn’t think about wind underneath.

So ply, then membrane, then battens, then tiles.

I was hoping to cut a step out, why are battens needed if I can nail to the ply? is it because tiles will hook onto the battens so better supported on sloping roof?

 

[Alastairreid]

9mm boarding across the rafters then membrane, counter battens down the rafters then tile batten.
The tiles hook over the tile battens which are then nailed or clipped, you will also need to weather the join between the building and porch.

 

[^woody^]

I can't see why you'd want to spoil a classic oak porch with ply or felt.

These things have stood for centuries without either.

 

[datarebal]

Oak style

 

[^woody^]

Oh yeah.

Ply and felt it is.

 

[noseall]

When we build an open (no ceiling) oak porch, we fit decor match boarding to the rafters prior the lath and felt, so you look up and see summat nice.