Roof leak help...

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Hi,

Had a single storey extension built last year. The roof is pitched, quite low but acceptable for the 4 velux’s apparently.

A couple of months ago, randomly, about a cup full of water just fell out from around one of the ceiling spot lights. I’m not talking a drip, about a cup full of water just fell out of it all at once and then it stopped. (It was raining heavily at the time).

I had it all out and the area around the spot didn’t feel soaking wet.

Anyway, builders came back and replaced a cracked tile at the top of the velux next to this spot. Everything has been fine since.

Again today, we’ve had consistent rain all day and the exact same thing has happened from the same light. Also, there is signs that water is running down from that velux area but nothing directly around the window itself.

I’m getting a roofer in but just wanted to know if this is a typical problem? The roof looks in decent condition, can’t see any cracked tiles looking from above.

Thanks for the help.
 

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starting from the top, no cavity trays fitted, have the cut tiles to the velux been nailed through the side flashing?
i can not see any flashing to the right hand side wall abutment
down pipe at the top discharges sideways into the tile channel , heavy rain could cause an issue here.
 
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A picture outside where the damp is would help as well. It could be an issue with the flashing etc, and the waters running down under the tiles to the bottom, or there could be an issue above the window where the damp is letting it run back. The damp above the window is even, but if it were a nail in the flashing at the side of the velux, then the damp would be concentrated at one side of the velux, not directly underneath it.
 
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Thanks guys,

For clarification there is no flashing on the right side of the roof because there is a gap between our extension and the neighbours wall.

The downpipe direct onto the roof has always concerned me but appears a pretty standard thing to do. It’s quite far over from the leaking spotlight aswell.

As far as I can tell the tiles aren’t nailed into the flashing. But I’ll double check this.
 
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nail in the side flashing can run down the underlay as much as anywhere else.

down pipe, turn the shoe down the slope, not clear in the picture but looks sideways.

check tile gauge, redland 49 , some look wide but could be photo angle
 
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Those tiles are not suitable for a low pitch roof.
Strictly speaking this is true. However I have seen them work with no issues at 15 degrees but with 100mm head lap.
in the picture they look far less head lap than that .
pushing a few up will show damp batten if that is the cause.
i'm opting for the downpipe
 
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Cheers for all the comments. Lots to go on.

Maybe I’m being stupid but what is the specific issue with the downpipe spout pointing sideways and not down the roof?

Or is the issue it shouldn’t be doing it at all and should be contained to the ground and into a drain?

The tiles are redland 49. If this was an issue though wouldn’t the roof be failing in other places? This seems isolated to just below the bottoms far right velux.
 
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These interlocking tiles are laid right to left. each have a channel and a channel over lap .. Think about it.
The down pipe empties to the left which in heavy rain just may flood the overlap.

Nailing through flashing, You say the tiles are not nailed through the flashing? If thats the case then the nibbed is knocked off and the tiles must be loose or glued in?

The tile gauge, simply measure from the bottom of one tile to the bottom of the one above , no need to lift anything, What is the measurement?

Failing in other places?, you can only see issues shown by problems with underlay, It could be wet all over below the tiles.

i'm guessing also you have celotex or similar between rafters? If there is damaged underlay higher up, water could run down on the insulation dropping through where the down lighter is fitted and also show at the ceiling to wall point

Possibly 2nd tile in, 6th course down has a damaged channel

Likewise 2nd tile up on the velux does have a damaged channel

Lots to go on? Handful of points that would take ten minutes to check.
 
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Cheers for that,

The gauge is 282mm so 100mm overlap.

- The redland 49 specs state this is ok for 17.5 degree pitch. This roof is between 17.5 and 20.

- The areas of damage you highlight are chipped corners only the channels appear fine.

- I’ll double check the tiles are loose I think

I think you are right about it running down the celotex and then out of the down light.

Might start removing some tiles around the window and have a closer look.

Cheers for help!
 
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You would be better finding a roofer who knows what he is doing than a builder who is obviously guessing.
 

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