Garage roof not pitched enough

[hanvyj]

Hi,

I just purchased a house. We looked around it in summer and had the Survey done in summer (not a full building survey).

Just moved in and, of course, it's been chucking it down. There is a huge leak in the garage roof.

I looked at it from the second floor window, it's black corrugated sheeting (assumed bitumen) with puddles of water on it. There doesn't seem to be any observable pitch at all to the roof so the water just pools. It's dripping in though the joints I assume along the whole length of the roof.

The whole thing looks brand new, not a trace of rust on the screws in the flashing. The beams, though sodden where the leak is are not soft and look new. The chipboard that is the ceiling of the garage is fine.

So yeah, very frustrating!

Is there anything I can do to waterproof it, if not is is a reasonable job for someone inexperienced to modify it so it won't leak?

I'm going to try measure the pitch tonight (don't have internet in new house yet) but I'm wondering how difficult increasing the pitch of an already installed roof is!

Opinions? (Any idea how much it would cost to get someone in to do it?)

 

[colind86]

get longer sheets if possible . Rigid ones.

 

[hanvyj]

Not sure I'd be able to get sheets long enough - It's quite a long garage (Could fit a car and bike end-to-end) but I don't have the exact measurements to hand.

 

[noseall]

Sounds to me like you have a very low end roof covering on a badly constructed roof.

Poor combination especially in a country with the rainfall we get.

You may be able to stiffen the existing roof with some makeshift purlins, but without looking we ain't gonna be able to comment.

 

[catlad]

Those corrugated bitumen sheets need a lot of support or they sag and leak.

 

[hanvyj]

I'll try take some photos before work tomorrow. Daylight is in short supply...

 

[hanvyj]

Sagging that's causing the pooling water:

My attempt at getting a pic of the pitch - it is probably about 3 degrees but I didn't have a tape measure...

The roof from the inside, chipboard and beams:

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[hanvyj]

Well those turned out pretty big photos...

 

[catlad]

You can get box profile steel sheets up to 7m in length, and just change what you have for self supporting ones.