Leaking shed roof

[mick1970]

Hi
I've had some leaks in my shed roof, quite heavy in one place where the underside has become quite sodden. I suspected water ingress through the nail holes, so I battered them all down and also put some clear silicone sealant over the top. However I found in last week's downpours I was still getting water through, but for the life of me could not see how.

This morning's frost however brought some new evidence. It looks to me like the leak on the right does go right back to a nail - i'll check it again. The leak on the left goes above the nail hole though. Could this be water going up from the seam? The overlap is only 6 or 7cm at that point. Not sure why it would be there and nowhere else though.

Any thoughts appreciated. Ultimately I would lift the felt and replace with larger overlaps but what would anyone recommend in the short term, as I want to insulate the shed so need to sort this first. Lift the felt at the overlaps and put down adhesive? Could I just run something along the edges of the overlap? Anything better to use to ensure all the nails are sealed?

Thanks
Mick

 

[Odds]

Two inches minimum is the rule and as long as the nails are galvanised it should be fine. It appears the water is running down the wood; perhaps there's a bubble inbetween the felt and the strut beneath?

 

[mick1970]

Well to sort in the short term I put a tarp over the top , weighed it down and tied it with guylines to the corners (enough to survive the recent storms!) . Water ingress seems to have stopped . So I'll make do with this until the weather is clear enough to look at replacing. I may go for one sheet of rubber to minimise any chances of leakage.