Replacing a flat roof

[F]

The front section of our garage roof is the one remaining flat roof on the house and is starting to bubble so I'm thinking of replacing it with a pitched roof.

The current shape is a trapezium and so I'm concerned as to how to cope with the side which creates the narrowing. Do I follow the current shape and have to cut tiles to follow the narrowing, or do I create an overhang to 'lengthen' the narrow end and make the roof rectangular?

Or something else?

Image at

if the above makes no sense. Approximate dimensions are: long edge against existing wall - 12' 6" narrowest edge - 4' other parallel edge - 6' 9"

TIA

[<me9]

BTDTGTTS

I'd make it rectangular and overhang the 2'9" at the narrow side. With suitable fixing at the house end it should cantelever ok.

You could either monopitch against the house, or pitch it both ways from a ridge above the centre of the width. Various neighbours here have done both, and one has made it hipped. Best choose what looks best. A hipped one following the line of the front edge may look the best, depending on the archtecture of the house, but would mean cut tiles. Other options /may/ allow uncut tiles, but cutting them with a diamond bladed angle grinder is trivial.

I'd go for what matches the house roof.

[F]

Me too!

Other flat roofs on the house have had the pitched treatment but this is the only one that isn't rectangular.

That was what I expected as cutting tiles to follow the narrowing seemed full of problems. Any chance you could offer some enlightenment on 'suitable fixing' to stop anything lifting out at the house end?

Monopitch against the house would be the match though I want to try to avoid too much brickwork in the new gable end. Bricklaying isn't something I enjoy doing...

[<me9]

Mine was in front of an extension, and the original roof joists were still in place. I fastened the end ones to the garage walls before removing the rest of the old garage roof. In your case, if they run from the house wall, and are supported by the front of the garage (or could be so arranged) a 4x2 wall plate attached to the house wall above the existing joists should suffice, together with a similar one below the new rafters.

I cheated and filled in the (in my case smaller) gables with cladding. It fitted in with the rest of the house.

[F]

We've got plastic fascias, soffits and barge boards so I would want to match those. Trouble is, I've never installed any myself and wouldn't know where to start in terms of identifying what I need, sourcing them and then how to fix them.