Detailing of flue through a roof

[angelboy]

I want to build a clay tiled roof over my oven where the flue penetrates the roof at the ridge.

How do I detail the top of the roof to make sure it's waterproof?

[david s]

Check your local authority for what they require. Most building codes demand a double flue if penetrating a ceiling because of the potential fire hazard posed by the timber or other flammable materials. You may also need some complex carpentry if you want it through the ridge. Most systems employ a Tektite seal on the roof side.

[angelboy]

The ridge is non-structural so I'll cut the board and double up the timbers (like you would in a stair opening). I'll use a single to twin skinned pipe convertor which will be the part that goes through the roof then build a box with 50mm clearance through the roof (like a chimney) then cap it with a high temperature silicone flashing to make sure its water proof.

I think that should do it and meet current regs.