Porch Roof Advice - Elements?

[EViS]

Looking for some advice on building a lean-to porch roof (1 metre wide by 0.7 metres deep), cantilevered off the house using 4x2. In terms of keeping the elements out, is this right for how to layer the roof?:

1. Plywood or shiplap cladding onto the joists
2. Felt
3. Battens
4. Concrete tiles
5. Lead flashing at 'ridge' where the roof meets the house wall (this will be inserted inbetween the mortar).

Is the plywood/shiplap necessary? If so, which is best? (there will not be a plasterboard ceiling inside the porch)

 

[ladylola]

Sounds ok, my parents house has such a canopy and has lasted over 50 years so far. The only difference is that their's is lead covered rather that tiles which to be honest may very well be heavier than lead and definately heavier than felt.
I'd also advise the use of treated timbers for the cantilevers and as to wheather to use ply or boarding then I'd say go for matchboarding (T&G with a vee joint) purely for cosmectic reasons.

 

[EViS]

Am I right in thinking that ply or t&g isn't usually required? Felt can be attached straight onto the joists and held with the nails holding the battens?

Only that in this instance, there will be no plasterboard ceiling so the ply/t&g will keep the dust out and look more aesthetically pleasing?

 

[SurreyRoofingEstimator]

You can do it without the boarding but for the look of the thing and the relatively minimal cost it's not worth it, if you do board it do use a counter-lath (12x38 should be fine) to allow a drape in the felt to allow any water that penetrates the tiling (not that it should) to escape

 

[EViS]

You can do it without the boarding but for the look of the thing and the relatively minimal cost it's not worth it, if you do board it do use a counter-lath (12x38 should be fine) to allow a drape in the felt to allow any water that penetrates the tiling (not that it should) to escape

What do you mean by a counter-lath? Where does this extra batten fit in?

Are you saying to run these battens from the fascia to the house wall and then fix the tile battens ontop of these? So that there is a gap underneath each tile batten?

 

[SurreyRoofingEstimator]

The lath is fixed up the slope (90 degrees to the battens) over the boarding then the underlay fixed over this

 

[EViS]

The lath is fixed up the slope (90 degrees to the battens) over the boarding then the underlay fixed over this

Got you, makes sense.

Could you also recommend which type of felt is required (or combination of layers)? 'Shed' felt, cap sheet, underlay, etc?

Would prefer to know the professional way of doing it as opposed to taking the easy route.

 

[SurreyRoofingEstimator]

As it's just a canopy porch you can get away with type 1F bitumen felt though something more modern would be better, if you are going to do it yourself maybe speak to a local contractor who may be friendly enough to give you an offcut

 

[EViS]

As it's just a canopy porch you can get away with type 1F bitumen felt though something more modern would be better, if you are going to do it yourself maybe speak to a local contractor who may be friendly enough to give you an offcut

What's a 'more modern' product?

 

[SurreyRoofingEstimator]

Something like Tyvek or Permo Forte underlay