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Wet patch on bedroom and bathroom ceiling. Help!!

(17 Posts)
Robhard91 Tue 19-Sep-17 20:01:49

Hello, I'm new to this so apologies if I've posted in the wrong section.

My girlfriend and I have recently moved into our own property and this morning we woke up to a wet patch on the ceiling of the bathroom and bedroom. I've checked in the loft and there are no pipes to cause a leak. Also we don't have a water tank in the loft. We do however have a bathroom extractor which runs through the ceiling of the bathroom out the vented roof tile.

I went up into the loft and the fibreglass beneath the vent is wet to touch as is underneath. Could this have been caused by condensation or am I missing something. Please help!

I've attached some pictures.

Many thanks.

Robhard91 Tue 19-Sep-17 20:03:21

More pictures. The house has had a new roof recently too so I don't think the roof is leaking.

wowfudge Tue 19-Sep-17 20:16:44

I think one of three things is happening- 1. there is a split in the vent hose and condensation is leaking out; or 2. the eaves are blocked with the insulation and you're getting a cold spot round the hose so condensation is forming in that area; or 3. the vent hose is just dumping moisture onto the insulation instead of venting to the eaves or through a special tile in the roof and it's seeping through.

wowfudge Tue 19-Sep-17 20:18:31

Missed that you have a vented roof tile - is the hose properly connected?

Robhard91 Tue 19-Sep-17 20:33:17

Thanks fudge. I'm pretty sure it's connected properly, should I disconnect the hose to see if it has any holes and should it be wrapped in insulation? I don't have a clue when it comes to this sort of stuff.

wowfudge Tue 19-Sep-17 20:41:14

If you can remove the hose to check it, then do so. Just another thought - is there any metal work in the roof above where the damp patch is? At work we get condensation forming on metal roof struts and it can drip down and make damp patches on the ceiling tiles. Metal is colder than other materials in cold weather and moisture condenses on it.

PigletJohn Tue 19-Sep-17 22:08:05

I can't see the duct in your photographs. Please put up some pics showing its route, and which way is up.

If it is flexible and has some horizontal or looped bits, water will collect in it, and eventually leak out of joints or the end.

PigletJohn Tue 19-Sep-17 22:10:49

oh yes, I see picture 3 now. Water will collect in that loop. If you lift it you will hear the water moving around, and it might run out of a puncture or join.

please show the whole route of the duct, it can probably be done better.

Robhard91 Wed 20-Sep-17 09:31:56

Hi John,

I've attached some more pictures. I've made an attempt to tape up a sagging bit of ventilation tube. What do you think? There is condensation in the duct and vent.

PigletJohn Wed 20-Sep-17 10:18:00

It's possible to get a duct with a drain, so condensation collects and runs down a pipe to some convenient place. Haven't used them.

I see the roof has recently been retiled, so I expect the roofers fitted the vent tile.

Rigid duct is smooth and hard, so less prone to collecting pools. But I can't easily see how it could be done.

Some modern duct is insulated, having an outer and an inner pip with insulation between them, which should cut down condensation. I haven't used that either.

Three things that will help are:

straighten out the duct to remove loops and hollows where it will accumulate

wrap the duct in loft insulation. It does not need to be a very thick grade. Use the brands treated with Ecose, which do not shed irritant dust and fibres. It is made by Knauf but sold under other own-brand names. "Ecose" will be on the wrapper. It is brown. Don't buy the yellow stuff. You only need the smallest roll you can buy.

Turn on the fan before you start your bath or shower, and leave it running for 20 minutes afterwards. Many extractors have a timeswitch to do that, and are usually wired to come on with the light switch.

If your fan is noisy or weedy it can be changed for a better one. Show us a pic please.

If I find my link to a supplier of ventilation duct I will send it to you, they may have a condensation trap or other solution if you phone them. AFAIK there aren't many companies in domestic ventilation, though there are some that do office and restaurant systems.

PigletJohn Wed 20-Sep-17 10:31:48

it's a company called "Epicair" in Kent. I had some duct, elbows and adaptors from them a while ago and they had a big range. There may be another company near you. Catch them at a quiet time and they should have recommendations.

examples They will want to know what size duct you have before you order. It is measured on the internal diameter of the duct, which is the external diameter of the spigot on the fan. 100mm is most common, larger sizes are better.

PigletJohn Wed 20-Sep-17 10:40:59


if you get the wet in cold dry weather, it's condensation

but if you get it in warm rainy weather, it's getting in through the roof tile.

Robhard91 Wed 20-Sep-17 11:13:42

That's a lot of great advice john. Thank you very much for taking the time, it's very much appreciated. I'll get working on the duct this weekend and purchase some of that insulation you mentioned.

I think we may also need to invest in a better extractor fan as well to be honest. It sounds very week and the bathroom is a small room so steam accumulates very quickly.

Thank you

PigletJohn Wed 20-Sep-17 11:36:17

post a photo of your old fan, please.

As you have a loft duct you can have an inline-fan in the loft, they are typically two or three times as powerful as cheap builders fans, much quieter, and better made.

examples this is a good maker

Robhard91 Wed 20-Sep-17 19:34:38

Here's the picture of the bathroom fan. I've taped up the ducting so there's no sag. I'm hoping this works. Think I'll monitor it for the next couple of weeks.

PigletJohn Wed 20-Sep-17 20:16:35

I don't recognise it. If you're lucky it might just be a grille with a more substantial fan behind it.

But builders like to install very little cheap fans of a nominal 80 cu.m/hr throughput, and too little power to blow through a duct.

The ones I linked have two to three times the airflow.

Robhard91 Wed 20-Sep-17 20:48:05

Cheers John, I don't think it's powerful at all you can just about hear it when it's on. I'll be buying one of them you suggested. Thank you for all your advice.

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