Buzzed the house roof the other with a friends drone to get a look at the flat roof area that runs along the dormer / stickout bit on the upstairs of the house. I’ve never seen it in the 2 years we’ve had the house, so wanted to check how it was made up, and if it was decent. It looked like this:

It hadn’t rained for 36hrs that time, and was a decent day … so a bit surprised to see the pools of water. Its been fine the last couple of winters, and there are no signs of water ingress from inside.

So if there are any roofers / folk who know, are there any suggestions to consider to try and address this?

Looking at the rest of the video file, it looks like there is a small lip at the leading edge by the gutter which is preventing the water easily running off. Also, even in that pic it looks like the boarding underneath is dipping between the supporting joists.

When fixing it, would it be worth trying to add a proper slope of some sort to the roof? It looks like I have enough height to raise the inner most side by a few inches to give it slope.

Then I wonder about what to recover it with? Is felt (whats currently on basically) still decent, or are there other options out there that are vastly better for the long term. (lead or a modern alternative metal alloy).

Long term is really what I’m looking for. I don’t want to be re-doing that roof every few years, I’d be happy to spend a little more if that gets lifetimes of 10’s of years.

cheers !

Water on the roof is not necessarily a problem as it can stop the felt from getting too hot which is what tends to cause the problems I believe.

There are lots of alternatives these days probably best with a GRP or single ply system. Personally not quite sold with the idea of single ply.

Fall on a flat roof is minimal usually.

I’m not a roofer but have a little experience in these things having worked with one for a while.

Best for lifespan would be a well constructed lead or similar sheet metal, however cost would be prohibitive.

Ime talk to 3 roofers, get 3 answers.
Mine needs doing, one guy says just reflect and forget about it, one says grp, another says don’t touch grp put a rubber roof down. Builder says pitch it, but that requires major alteration to the upstairs of the house.

Buggered if I know what to do and I get a puddle in the kitchen when it rains. 😆

Not a roofer but work in commercial real estate and we use this stuff:

http://www.kemper-system.com/UK/eng/

Should work for smaller scale domestic use too, just need to find a friendly supplier and installer.

Just leave it. When it leaks get a good single ply membrane fitted. This can be laid almost flat and puddling is fine. Used on most commercial buildings these days. Good for at least 10 years and no one will nick it. Grp is prone to crack so I would avoid.

not done roofs for a number of yrs, what we used to do when the old roof was tripped off was to add a taper fillet 75mm to zero rear to front on the joists to create a greater fall on a flat roof then fit the roof as per spec.You’ll need guttering at the front of dormer looks like you have these fitted already

This stopped the ponding of the water on the flat roof.

I work in the roofing industry.
All systems have their place if installed correctly. I’d choose a reputable installer first over choice of system.
Single ply , ok but only as good as laps and details. Very easy to puncture. We see new builds riddled with defects caused by other trades dropping tools, scaffold,etc. I’ve seen very expensive rubber roofs fail due to poor workmanship.
Felt still reliable,tried and tested but again very much depends on quality of detailing and installation.
Modern generation liquids can be very good, but can vary massively in quality. Roofers think they are a cheap fix and tend to be sniffy about them, especially if brought up on traditional felt, bituminous or asphalt systems but can be excellent if done right.
Roofers’ opinions on systems very much depends on their own area of expertise.
First and foremost go by reputation.
Most of our work is in the commercial or retail sector rather than residential but might be able to point you in the right direction depending on where you are?
With regards to ponding water, this isn’t necessarily a problem in itself but may expose any defects in the laps if a sheet system in the long term.
I’ve had a flat felt roof that has held up fine despite ponding for years.
Ponding issues can be corrected with firrings or cut to falls insulation boards if you want to improve thermal efficiency at the same time.

This is interesting as we have a slight leak on our dormer extension. Trying to get people out to quote is proving tricky. So far one place has quoted £2100 saying they would replace the all the felt (I thought it was just a seam fix – though no one has been up to look yet). The felt is approx 7 years old, fitted by the previous owner. Husband asked about the rubber stuff and they said birds peck through it!

Anyone know any roofers in West Yorkshire/NW Leeds?

It’ll depend on the structure beneath and its ability to take additional weight. Torch-on felt is a good compromise between cost and lifespan with 20 years being a safe guess
Rubber will last longer although it’s more expensive. Rubber is also a more attractive option for less experienced roofers
Lead will weigh more than either of the above, several hundred kilos for a roof that size
Any roof is only as good as the person putting it up, and that’s what you’ll pay for

We had our garage/extension roof done a few years back, like-for-like with felt and it’s been fine.

Don’t know how old the dormers are but might be worth asking about getting a ‘warm roof’ fitted if you do go for a change – an extra 50 or 100mm of insulation would probably make a big difference (although it might need some work on where the flat roof joins the pitched one). We looked into it and decided not because we didn;t really use the room in the extension much but we do now and it’s noticeably colder than the rest of the house, wish I’d done it now.

Those that having fitted the EPDM sheeting is there any requirement to cover with stone chippings to protect from the sun as you would with felt bitumen.

We have a beach hut in a row of 7 that all had GRP laid over marine ply (convex roof so no puddling ever). After about 15 years a number of the GRP coverings had peeled off in wind. We had a company come in about 3 years ago and replace all the GRP roofs with rubber.
Looks much nicer (no chippings necessary Craig), 20 year guarantee AFAIR and seems to be doing a great job.

Thanks for the suggestions so far. Certainly more to be looked into.

My gut feeling says that the top covering is a secondary matter compared to addressing why its pooling in the first place, and that the principle thing to achieve is a some sort of slope that would allow the water to run off correctly.

Grp is prone to crack so I would avoid.

News to me, that.
We had our kitchen extension done with GRP about 5 years ago and it’s been great.

Came with 10 year warranty and the guys fitting it reckon it’s good for at least 25 years.

It’s basically the same as a boat hull but laid on 18mm roofing board. I’d be worried if boat hulls were prone to cracking when made from GRP.

Not really, boats tend to be either thicker, made of much higher quality materials or form a sandwich with other materials. Plus they are protected by a layer of gel coat which protects them from the elements.
From what I’ve seen GRP flat roofs can dry out and crack – seeing one GRP roof next to us that had entirely peeled away from the ply below and blown away was quite an eye opener.

Trying to get people out to quote is proving tricky

NW Leeds here too, finding the same problem, must be more work on then than roofers, only had one £5K quote (!) for two roofs in GRP. I don’t really want to do it myself but could save £4K for a weeks work…

I did our garage myself in EPDM, used Firestone brand, still as good as new over 4 years no cracking, pretty tough I walk on it to cut the hedge. Used this supplier on eBay.

For our dormer though I might use GRP only some of the shaping is a little complex for sheet of rubber. This GRP supplier has a good guide for installation.

Advantage of EPDM or GRP over felt / bitumen is they are seamless. I wouldn’t use felt again on my house, too many possible points of failure, old technology. I bet not many installers would offer a 10 year guarantee on this kind of roof.

Plus they are protected by a layer of gel coat

Same on a roof. If the installs you have seen haven’t had this then that might explain why they failed. It can be badly fitted, but if done properly it lasts a long time.

GRP flat roofs can dry out and crack

??? What “dries out”? They are dry from day 1.

Nothing wrong with properly fitted grp. It’s even fairly easy to DIY as long as you follow the proper process. It’s also easy to repair should something happen

The resin can become brittle which allows the cracking.

The resin usually becomes brittle of a UV protective coat isn’t applied last.

We’ve had a number of GRP roofs done and they’ve been brilliant but they’ve got to be done properly (like anything else really).