Noise in Flat Roof??Leak?

awishawash

Hi all,
I am being driven nuts by a dripping sound onto my new ceiling(insulation, plastic sheeting, plasterboard). Its like being in a chinese torture chamber. I'm nearly sure its only just arrived after I did a little bit of jackhammering in chasing a wall. I half took down 2 slabs of plasterboard where i thought the sound was, and moved the sheeting around, no change.
I then climbed up onto the flat roof above it and brushed off water/lychen that was ontop of the place i thought the noise was. I thought this would stop the noise for sure. Maybe its the plasterboard expanding with the radiators being turned on? I thought plaster didnt expand or contract though.
If its a leak should i paint the flat roof with tar or something, and how long would it take to dry the roof space out?
Thanks for any help!!:)

rooferPete

Hi,

Do you have any photos of the roof ? what was the condition of the timber deck like when you walked on the roof was it spongy or solid underfoot ?, what does the roof covering look like ?.

The first thing to do is find the cause of the problem and fix it, if your roof finish is old and should be replaced try and do that before the water rots the timber.

The time for the roof space to dry out depends on a few things but mainly the way it is vented, and if the insulation is tight up against the decking or has room for a through flow of air.

Regarding using tar based coatings / products they are usually a short term solution if they work at all, standing water and lychen growth do not indicate a fall on the roof to allow the water to run off.

Your roof can be tested with non destructive moisture detector that should tell you (or the operator) if there is water getting under the roof finish and in most cases give a fairly accurate location of the point of ingress.

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awishawash

Thanks for the response rooferpete
looks like ive opened up a can of worms, got a better look at the roof today. Its a cold felt roof, spongy in places, there is water sitting in a few spots. It definitely needs to be redone as the fall is gone, but i just dont have time or cash to do it right now. What I did was dry it up and paint it with liquid felt. As I'm putting in a shower unit below it aswell I had to take down some of the ceiling and its more bad news, the joists are rotting and are a brown black colour around 6 inches in. The chipboard deck has a mould or fungus on it, white/yellow type stuff. I cant tell if its dry or wet rot, dry being the one I cant patch up? Its on damp spots and dry spots. Can I paint the lot with a fungicidal paint or anything else short term until I can replace the lot? Should I have it sprayed? Need to keep the costs low.:(

rooferPete

Hi,

Sorry for the late reply, have you checked the joists with a screw driver or similar to see if the dark colour is rot or creosote treatment when the extension was being built ?

Personally I suggest leaving the rotting chipboard alone, there is no cure that I know of for extensive rot caused by the chipboard soaking water.

I would suggest that you use a polythene sheet under the joists before fitting the ceiling to prevent moisture from the shower area getting into the roof making it worse.

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awishawash

Thanks for the response rooferpete, I'm such an idiot. The dripping sound is the overflow pipe from the boiler dripping water from a height onto the roof!
It will need to be redone though as there is no fall and is just full of puddles. Loads of damp on the wall aswell as the rot on the underside of the deck.
The dark stuff on the joists is creosote but even still they are not pretty.
Thanks for the help!