leak in new velux

[marsaday]

I have installed 5 veluxs and have still to plasterboard out the attic. good job really as i have just found i have a leak on one due to all the snow staying on the roof.

The leak is coming in at the top of the velux. This is also positioned about 4 courses down from the ridge.

i can take a photo, but just wondered how do i find where the leak is coming from. the roof doesnt have any membrane and is just slated.

 

[SASroofer]

Did you nail a slate through the velux back tray?

Or did you support the back tray correctly?

 

[datarebal]

seeing as i's only 4 courses down it should be easy to locate the leakage. check all bonds and be sure there is enough lap over the back gutter. Remember there will be two thicknesses of slate laping here..
Also double check all screws have been fitted and tightened correctly

 

[xfr]

probably coming in from the ridge tiles!! are they mortar bedded.water will be running down the felt dripping in back of velux

 

[xfr]

just read thread no felt??? so running down back of slate if wet fix

 

[marsaday]

yes i am thinking it is the ridge which has some gaps in it. i did see some, but they were very small, but with the snow sitting on there at the moment i think that may be why it is dripping through.

when the snow clears i will get up there again.

the top flashing / back tray is supported well and yes i have nailed through it, but towards the top. otherwise i couldnt get my tiles down. how else do you secure the tiles if you dont nail through the flashing. The last course sitting at the top of the velux and so at the bottom of this flashing has been hung using tile hangers.

 

[datarebal]

how about an external photo?

 

[marsaday]

will try when snow goes

 

[SASroofer]

You would normally double batten above the back tray, leaving enough batten showing to fix to, then re-hole the slates higher up, you're not supposed to nail through any part of a velux flashing kit.

 

[marsaday]

ok, that helps. when i get back up there i will double baton the tray and seal up the holes made.

i have done all 5 veluxs like this and 4 are fine.

 

[alittlerespect]

Hi!

You have answered your own question - no sarking felt equates to plenty problems - you will probably find that the snow has been blown up and over the top of the tray to the velux window by the pressure of the wind, the snow has subsequently melted and only has one way to go - the easiest route - down! which is where sarking felt really comes in handy!

One solution that may work, would be to remove the tile courses above the velux, de-batten and introduce a local area of sarking felt to catch the snow and divert the water back from where it came in the first place, and reinstate the tiling!

You would obviously need to dress the sarking felt over the top of the tray to the velux and to this end it may be useful to introduce a run of lead to extend the top tray and then dress the sarking felt over the lead!

Regards

 

[marsaday]

right thanks for that. i will take it into consideration when i get up there.

Will have to wait for some decent weather and so i wont be plaster boarding
this section of the roof until it is sorted.

leak has stopped now as snow has melted away.

Had some terrible rain since the summer when all the windows went in and no leaks at all. good job it has snowed now because i was soon going to start PB'ing. All insulation was in.