Which of These Products For Waterproofing Ply Under Felt?

[ILikeDIYS]

I'm doing the sides of my poly-carbonate veranda with ply.

So far I:

Run exterior wood glue around the edges of the ply wood.
Painted the under side with Ronseal wood treatment and exterior stain/varnish.

Now I gotta do the top side which is going to be felted (just one layer of mineral felt torched on).

Which of these products should I paint onto the ply before laying felt on top:

SBR,
Bitumen roof primer,
Exterior white primer paint,
PVA glue,
Exterior wood glue,
Varnish,
Nothing just torch the felt on.

Not prepared to buy any other products, this is all I got and need to do it tomorrow.

Was thinking one layer of SBR, then one layer of roof primer.

What do you guys think? Cheers.

 

[HERTS P&D]

Fibreglass it!

Andy

 

[ILikeDIYS]

Fibreglass it!

Ain't nobody got time for 3mm expansion gaps and drip trims!

 

[Alastairreid]

Bitumen primer is all you need...wait till its dry before you go near it with a torch.

 

[ILikeDIYS]

OK cool. Is there any downside to applying SBR under roof primer though? And is roof primer waterproof in itself (just in case the felt doesn't do the job)?

 

[Alastairreid]

The primer is to help the felt adhere to the wood.
Sbr as a roofing primer i have never heard of.

 

[geraldthehamster]

EPDM!

 

[ILikeDIYS]

Job done:

 

[Alastairreid]

Very tidy.
Dont think you will have long to wait till it gets tested.

 

[ILikeDIYS]

If it fails the test I have tricks up my sleeve

Definitely not worth over-complicating something like this with fiberglass or EPDM.