Rain water behind fascia board on flat roof

Hi guys,

I've just had a warm deck fitted on an extension but there is water running down the render behind the fascia. It looks bad as the water is discoloured from passing the RSJs. The drip trim looks like it goes into the gutter ok - fascia front is dry. The fibreglass roof looks good and there is no evidence of water inside the house either.

The roofer is not disputing the work is hos fault but wants to eliminate any other work 1st before redoing it all! Hes never come across this and neither have I.

It only happens when it rains so its not condensation as he suggested. Any ideas??

ll attach a few pics so you can see

Thanks

 

Not quite sure i get ya? The water all runs over the front edge as it should. There are small pools in places but im guessing thats because of the lip of the trim