low pitch roof on kitchen extension

[ass17]

Hi folks, need some advice please.

Have a kitchen extension that was built 2.5 years ago. Due to bad weather I have had a build up of water pools in one corner of the velux window, a 4m span across where the roof meets the vertical wall, and a random spot in the middle.

On inspection the roof pitch is not the 18 degree BUT 10-11 degrees, and simple tyvec membrane and large marley modern tiles. This was signed off by Building Control.

What are my options in terms of: Are Building Control at fault or partial blame for the issue? If so can they be liable to foot some of the cost of a repair?

Also what repair would you suggest on a roof this bad? I was thinking a specialist tile like Decra and a better membrane, is this the only answer? I dont think I can raise the pitch to 15 degrees without going above the level of the upstairs windows which could be expensive.

Would love some advice please....

 

[catlad]

If it was my roof then I would be blaming the person who did it .

 

[ass17]

I could do but it wouldn't help, were 2.5 years on from it being built and the contractor cannot be contacted, surprise.

This is why I'm looking for a solution rather than pointing the finger.

 

[catlad]

Well pointing the finger at building control will get you no where, I think you would be better off putting a membrane down on a pitch like that.

 

[ass17]

I know in reality than I'll get nothing from BC but I find it remarkable that they couldn't see a 10 degree pitch??

Any clues to which membrane to use?

 

[ass17]

Is the cheapest solution to keep the tiles and fit a Klober Permo Extreme RS SK2 Vapour Permeable Roof Membrane?

 

[ass17]

Or two layers of
Dupont Tyvek Supro Breather Membrane

 

[ass17]

Or kingspan nilvent, what is best suited for 10 degree pitch?

 

[ass17]

Or permavent max?

 

[chris_o]

Found any more yet?

 

[noseall]

Put a flat roof on it and lose the Velux.

 

[ass17]

Flat roof not an option, not enough light.

 

[chappers]

put the velux on a flat roof kerb

 

[ass17]

put the velux on a flat roof kerb

Surely it's still cheaper to put a better membrane down than to replace the whole roof with felt/ply flat roof and add kerbs..

 

[noseall]

10 degrees is practically flat, especially in terms of the Velux. This could be your weak spot as far as water ingress is concerned.
The designer wants flogging.