Finding the leak in my roof

[Black Sheep]

I've got damp markings on the celling of my front bedroom
The house is a mid terrace (apparently used to be an end once upon a time) built around 1912-1915
The celling is plasterboard screwed through the cracked artex ceiling with a skim added.

This mark is in the shape of an F with the light fitting being on the lower horizontal mark, presumably at the joins in the plasterboard.


From outside the tiles appear to be ok, can't see any out of place. I've had a roofer look, he says the roof has dipped slightly in comparison to our neighbours or there could be a cracked tile somewhere that we can't see without stripping the slates off - his solution, to guarantee resolving the issue, is to strip, underfelt and re-slate. I can see his reasoning.

We're wanting to look into having a loft conversion / hobby room later this year so doing this now isn't really fitting with logic to re-roof, to end up re-roofing but I don't like the fact the light buzzes and crackles from time to time if it's rained recently.

As far as I'm aware it's not actually dripped.

I have had a look up in the loft and can't see any chinks of light coming through, had a glance today while it was raining with a torch but couldn't see any signs - bit worried about climbing in properly as I know the joists are only thick enough to hang the ceiling not take my weight.


Basically I want to divert this water from the electrics to somewhere it can sit and dry out as it appears to be a couple of drops finding their way through.

 

[vernon]

How about spreading a tarpaulin over the joists?

 

[summerdays]

Have a look when it is pouring down, it is usually easier to see then. My current place and the previous one have both had leaks for various reasons. Could it be a problem with the ridge tiles? The water may run along a rafter before dripping meaning the leak isn't above the drip. Or it may only happen when the wind is from a particular direction, the last leak that we had fixed which was caused by a crack in the flashing but only a problem if it was a SE wind.

As we intend to have the roof off for major works next year we just asked for a bodge job rather than a full repair and so far it has held.

 

[slowmotion]

A friend had the same problem, but he was about to sell his house. He stapled a cheap tarpaulin to the underside of the rafters and led the leaking water via a discrete pipe into the external gutter at the eaves.

He then plastered over the loft hatch and slapped on some paint. Very naughty.

 

[Yellow Fang]

Can you get into your loft?

 

[Fnaar]

Miss Goodbody up the road asked me to have a gander at her wet patch. Oh my! Looking through my binoculars, I noticed that her ridge was so compromised, I'm not surprised it had a constant drip! I'm going to inspect her eaves tomorrow and see if I can access her rafters, and thus get to the ridge, to slap some filler on it.

 

[biggs682]

Miss Goodbody up the road asked me to have a gander at her wet patch. Oh my! Looking through my binoculars, I noticed that her ridge was so compromised, I'm not surprised it had a constant drip! I'm going to inspect her eaves tomorrow and see if I can access her rafters, and thus get to the ridge, to slap some filler on it.

@Fnaar you made me laugh thank you

and i was worried about putting a silly comment about how we always plant our leaks in the garden but why was i worried

 

[jazzkat]

As you've found out finding water ingress in a loft is a nightmare. It travels and where you see it isn't where it comes in.
You should be ok walking on the joists in the loft, as long as you are careful. If you want to be mega sure get a couple of boards to spread your weight across a few joists. Be careful and don't fall through the ceiling!
I'm afraid I've got nothing to add other than to say good luck I hope you get it sorted.

 

[Garethgas]

Go into attic and rig up a decent light.
Put a few planks down to spread the load of your weight.
Lay some tarpaulin across the suspected area as flat as possible
Lay lots of absorbent paper (kitchen roll, blur roll) flat on top of tarpaulin
Wait for rain or hose the roof
Inspect paper for dampness.

 

[MarkF]

Yep, you need to go in the loft when it's raining, but, as somebody else said, wind+rain may be needed for the water ingress. Wood will be damp and discoloured, you may be able to follow the trail..............I ran a roofing company, often, people could not afford to have the correct work done, so to stop the leak we used the below product. I can recommend it.

http://britanniapaints.co.uk/wp-content/uploads/pdfs/Roofs/Emergency_Leak.pdf

 

[threebikesmcginty]

A friend had the same problem, but he was about to sell his house. He stapled a cheap tarpaulin to the underside of the rafters and led the leaking water via a discrete pipe into the external gutter at the eaves.

He then plastered over the loft hatch and slapped on some paint. Very naughty.

'Friend', yeah right.

 

[shouldbeinbed]

Our roof is bonded down with the expanding foam type stuff (dont ever do this to yours) then the flashing failed.

+1 to everyone saying water travels - I followed the leak up from the point it was discolouring the ceiling and could see with a bit of practice how it was running down the joist from much further up and dripping only when it hit a rougher area.

A bit of practice was lying on my back in the loft in the rain for as long as it took to attune my eyes to the differences in the wood & eventually see the little trickle of water

The roofbonding people turned out to be utter cowboys so whilst arguing the toss and legally with them over what a roof included (not lead flashing apparently) I used some metal staples used to strengthen small wood joints - corrugated about half an inch deep and 3/4 inch long to build a wall in the joist to funnel the water to where I wanted it to drip so I could get a bucket under there easily, worked a treat without fixing the root cause. I lost out to the cowboys & used a different roofer who put on a heavier duty, longer term version of the stuff @MarkF links to which has sealed my flashing perfectly for many years now.

 

[slowmotion]

'Friend', yeah right.

No, it wasn't me but I still admire the ingenuity, if nothing else.