Roofing Question

[DiscoStu]

Not sure if this is where this question should go!

I am building an 3m x 3.25m Spa house, to house a hot tub. The house will be largely open on two sides with a canvas roll down cover. So it isn't going to be sealed completely watertight. I am making the roof using marine ply and I want to put self adhesive shingles on it, but should I put something between the marine ply and the shingles and if so what? i thought maybe a felt roof, but I wasn't sure how that would work with self adhesive shingles, i wondered if they might not stick very well?

Any thoughts or product suggestions?

 

[mouppe]

I'm no expert but pretty much everyone here (in Montreal) uses a membrane in between the wood and the shingles. They used to just cover the first six feet or so up from the roofline, but now most people cover the whole roof.

 

[Steve Maskery]

Stu
If you are shingling it, I don't see how SA ones would stick to a membrane.
OTOH, if you are using shingles, why do you need (expensive) marine ply.
If I were you, having just watched Ray do a roof I would suggest you consider OSB3 instead of marine ply, your membrane, laths and then your shingles.

Alternatively, if you want just pretty and nothing else, rafters, laths and shingles. It will look pretty from the inside. You don't need all this modern stuff like insulation, do you?

Sounds like a nice project. Candles and cocktails?

 

[DiscoStu]

Well I've already ordered marine ply, so let's go with that!

So I can just stick my self adhesive shingles directly onto the marine ply? If so then that's cool.

I have seen marine ply expand over time so I am keen to do what I can to make this roof last for quite a while.

As a project I'm quite looking forward to it. I'll stick a sketch up image up if you want to get an idea of what it's going to be like (Famous last words)

 

[Steve Maskery]

Well I am no roofing expert, but I see no point whatsoever in putting a membrane between the two. What will it do? Nothing, as far as I can see.
I'm sure it will be fine Stu.

 

[DiscoStu]

 

[blackrodd]

The only self adhesive shingles I'm aware of are, basically, cut felt strips, that I've used several times, as Wickes sell,
Personally, I like the results.
http://www.wickes.co.uk/Wickes-Red-Roof ... 4/p/164088
IIRC, you should lay the shingles on polyester base coat felt, I think I nailed it at every which way, at 12".
The sun heats up the adhesive, which is designed to weld with the polyester pre coat, not sure it would bond on ply!
Without being stuck, It will be pretty useless in the wind as the felt will just lift and let water in.
I used painted guttering for the ridge
This information will be on the packs, or you could get the good ideas leaflets that the do.
Regards Rodders

 

[DiscoStu]

Thanks more good intel! So I need some polyester base coat felt now.

 

[lincs1963]

I'm no expert but pretty much everyone here (in Montreal) uses a membrane in between the wood and the shingles. They used to just cover the first six feet or so up from the roofline, but now most people cover the whole roof.

Thats right, but that is for wooden shingles, cedar or whatever. These shingles being talked about here are just cut and shaped pieces of mineral felt.
Also, Steve, shingles of the timber variety are not fixed to laths, they are nailed to a ply or osb skin.

 

[DiscoStu]

Does anyone know if there is any good "glue" to use to stick under felt onto ply with?

 

[No skills]

I know nothing but I would imagine its going to be a bitumen based paint/glue/undercoat, I think some felts are torch on so be sure to confirm what you are buying before parting with any money.

 

[blackrodd]

Does anyone know if there is any good "glue" to use to stick under felt onto ply with?

I have answered this question on you're other thread, In some detail. and have been trying to find out why my post has gone missing!
Could you please use one question on one post at a time?
Regards Rodders

 

[DiscoStu]

So today's efforts:

Not a lot to show in a photo but I did all the edging, did the gable ends and I've fitted one roof sheet and I've made a door that leads down the side ally.

Tomorrow should look more impressive. I think the photo was from quite early in the day.