Flat Roof leaking - no obvious holes or blistering

[oldbutnotdead]

Thats fairly shoddy not stripping the old deck. You've got a load of damp timber in an unventilated space, it'll continue to rot and cause your new covering to go all baggy. EPDM is more tolerant of movement in the deck than felt or GRP but be interesting to know whether he screwed/spiked to the joists or to the old deck. Also it is much easier to inspect the joists from above...
As others have said you could do with more fall on the roof but you're limited by that window- do please show how matey has weathered the roof to the wall, he's built the roof up by 25mm so even worse at that window.

 

[oldbutnotdead]

It does look as though he's cut a chase at a decent height for a cover flashing. I'm not au fait with EPDM so don't know if there are special upstand trims (as there are with GRP).

 

[Alastairreid]

Did you pay him to renew decking?

 

[gwernybwch]

Thanks all for the replies.

The roof is a ventilated space, so the old decking will dry out (and touching it, it feels like it has already done so). But I'm guessing that the old stuff will continue to rot.
It looks like the new decking was at least attempted to be screwed to the joists (although I can see some 'missed' and are screwed to the old decking).
There is a slight fall on the roof, I would say that it is 20mm at its highest.
@Alastairreid When he viewed the job, I said that I wanted the old to be removed, looking back at the written quote it only said "remove existing felt".

I've had a look at the flashing around the window sill and, err, there isn't any!
it looks like the rubber has been run up to meet the bottom of the sill.


What are my options here?
If it was stripped back again, is it possible that some of the new materials could be salvaged? Or do I leave it knowing that at some point there is going to be water ingress under the window sill and that the old decking will contine to rot and the roofing will look poor?

 

[ted456]

if the old OSB was removed he would have had another 20mm to play with for a 40mm min fall.
any upstand below the sill in the last pic will work only if the sill has a clean throating and theres actully an upstand flashed below the sill. if the throating is damaged the rain can run back under the silland could get behind the low upsstand.

if it was my roof or job i'd strip it back to joists and not play about hopin for the best. who knows what else hes messed up?
most all the mats will probably have to be skipped and new needed.
extra work but joists could be lowered at the wall plate for a good falls.
a clean throat could be grinded if needed.

 

[oldbutnotdead]

Thats better news. While you've got access it may be worth spraying the old deck boards with some wood preservative (either use water-based or avoid the gaps where you can see the undersheet).
The cover flashing looks nice and neat though he's been naughty doing that long run (1500 mm sections is the theory). Do you know how deep the chase was (he should have gone 25mm into the brick, he's probably gone 25mm into the render so 10mm into the brick).
Very little salvage if you strip it all off.
Under the window- check the underside of the sill, make sure there's a drip edge (a channel) in it. If there isn't then make one (a bead of silicon will do but it'll be a pain doing it cos no room).
Have you chucked any water at the roof yet to see how well it drains? Best using a hosepipe with a sprinkler head to simulate rain. 20mm across 4000 isn't ideal but as long as there's not too much ponding it'll be ok.
It would have been better to strip the old boards and sort a decent fall but you are where you are.
He appears to have done a decent job with the rubber (no lumps and bumps) but you'll see more clearly when you wet the thing. Have a good look at corners as well.
Bottom line is he's polished a jobbie there, hose it and see what you think. If you've got the budget then now is the time to sort it...my take, if there's no ponding under the window & the drip edge is good you'll be ok.
Routine maintenance task will be to clear rubbish, moss etc from under that sill every 6 months or so