roofing tiles and angle of slope

[John Kelly]

Bit confused over this.

Plans we have for our house show the angle of the extension roof to be about 20 degrees. Looking on the

says that the minimum roof pitch would be 30 degrees which is quite a difference and makes the extension room more of a corridor, and hence not a lot of use. I have to say that the plans were drawn up by an architect over 6 years ago by the previous owners who divorced each other rather than doing the extension.

Maybe I'm looking at the wrong website for the roof tiles we've got - I don't really know which ones they are but they do look like old english pantile according to the website pictures.

Anyone any advice on just how low you can go with roof tiles?

Thanks

[Danny Burns]

In message , John Kelly writes

Depends on the tiles. I know that many interlocking tiles can go as low as 17.5 degrees. Stonewold is one that comes to mind.

Are you sure about the 30 degree bit most tiles can cover at least 22.5 degrees.

[Colin Swan]

Our rear extension is 17.5 degrees, but had to be done in tiles that would work at this angle, and you have to get the overlap right. I think you can get tiles that will go down to 15 degrees, so you should be fine at 20 degrees.

I think my tiles came from Redland...

-- Colin Swan

[The Natural Philosopher]

Very low. Sub 15 degrees with machine made interlocking tiles, however careful laying is necessary.

40 degrees is a practical minimum for slate or peg tiles. I wouldn't consider pantiles at anything less either.

Below that you really need to be careful, overlaps may need increasing, or maybe even a roof of plywood covered with waterproof membrane and the roof material more decoration than weatherproofing.

Consult a good architect.

[Bob Mannix]

Firstly, if the plans were passed back then, you will have to resubmit for planning approval anyway (AFAICR 6 years is somewhat too long!). To avoid unnecessary cost, I would ask for an interview with the planning department, explain the situation and ask if the roof slope would preclude passing now, before resubmitting.

Secondly, I did hear (today) from someone who got away with 20deg (with some restriction on the tiles) although the local authority set a minimum of

22.5deg .

[Michael McNeil]

I shouldn't think there would be much danger if the new roof is sheltered by the original building. The problem is that rain may be blown back up the underside of the tiles.

I would go for the widest possible roof. Then -if there is a failure, take the tiles off and put some damp proof membrane in or a couple of lines of silicon with each course of tiles.

How many tiles high will the roof be?

[Rick Dipper]

My architect told me today that 25 degrees is "about as low as he would go" for slate tiles, we settled on 30, as "you have to be an idiot to get it wrong at

30 degrees".

Rick

[Peter Taylor]

Sandtoft Double Pantiles - minimum pitch 17½°

types:

Redland Regent, Delta & Stonewold 17½° Redland Grovebury, Norfolk Pantile, Redland 49, & Richmond 22½° Natural and Artificial Slates 30° Clay plain tiles (double lap) 40° Concrete plain tiles (diito) 35°

[The Natural Philosopher]

Thanks mate. I am surprised that pantiles are in the 22.5 degree bracket tho.

[Peter Taylor]

The info comes from the Redland Red Book. Remember this is Redland's interlocking single lap version, not traditional clay pantiles. I don't know for certain what pitch these can go down to but definitely shallower than plain tiles.

[John Kelly]

Not sure yet. Still waiting for the architect to come back to us with his preliminary drawings. Seeing some of the posts here gives me hope though as all I need is interlocking tiles and it should all be fine down to 20 degrees which is what the old lans said. Didn't mention interlocking tiles though.

Thanks

[John Kelly]

[N. Thornton]

Hi. If youre willing to put durable waterproof sheet material on first, then tile over, then the tiles dont have to be water impenetrable, and one can go very low indeed.

Regards, NT

[Tony Bryer]

Marley Wessex 15 degrees: