Flat roof woes...

[Ingr]

I have a large flat roof on an extension that was new 2yrs ago. It leaks. I have a 3ft stain on my kitchen ceiling and two more in my utility. I've given up with the original builder as he's been back 4 times to repair it but can't find the fault. The roof is surrounded by a parapet on all sides and one third of it drops lower like a swimming pool due to ground level changes. The worst leak is not on the lowest bit. I've had a quote from a reputable top company to totally remove and replace as they say the original roof construction is so poor it isn't fit for purpose. It did however, meet building regs at all stages. The new company have an insurance backed 10yr guarantee. Their charge is 6k for felting and small modifications. This aside, I'm wondering if there is an alternative to felting, like zinc perhaps that would last longer/be more durable? The roof is about 30ft long by 9ft wide. The sunken bit represents a third of that. What would be the best solution?

[BennyTheBall]

Does the parapet have coping stones?

Regardless of whether to roof is felt, rubber or fibreglass - it should still perform the same.

The gradient of a flat roof should be at least 1 in 80 - have you checked this?

If you get it re-done, I would recommend you only use a contractor registered with NFRC.

[Ingr]

Yes new contractor is registered. Yes the existing roof has a gradient. & yes the parapet has coping stones. Do you think zinc would last longer?

[LittlePickleHead]

Oh god watching as we are having same issue with a 2 year old flat roof and right now have someone doing an emergency repair as water was literally running down the walls. No matter how many times we've had it repaired it still leaks. Original builder also given up. Can't afford £6k. Thoroughly depressed!

[PigletJohn]

"swimming pool" is called Ponding and indicates the builder was incompetent.

Flat roofs are prone to sadness. Ask around for a well-recommended local flat roofing co who have been in business for some years and have not gone bankrupt and changed their name slightly every few years (look on Companies House but only the .gov.uk website).

BTW adverts on builders website where they pay for a listing and edit out unfavourable reviews are not the same as recommendations.

[OCSockOrphanage]

We had to have a large flat roof (which is also a terrace) replaced as our first act when we moved 20 years ago. The original was fibreglass. I asked an acquaintance for a recommendation and got a name. They installed several layers including a felt layer, topped it with bitumen, then tiled it.

And job done; it has been perfect ever since. The company is still trading, and I see their vans all over the place. There are some gems, you just need to find one, and they weren't even that expensive, although the bill hurt at the time!