Hi Guy’s, it’s been quite some since I last posted something here… The middle extractor pipe that leads out to the roof is depositing water (vapour turning into water) in the u-bend – see Pic 1 with the white string around the problem pipe. Some back ground. The extractor pipe closest to the wall in Pic 2 services the 2nd floor bathroom and the 1st floor shower room directly below it. The extractor pipe furthest to the right in Pic 2 services the 2nd floor en-suite bathroom only. The extractor pipe in between the above two pipes (the problem pipe) is not servicing any bathrooms as far as I can see, and there are no other fans around the house? Here is the weird observation. When investigating the above, turning the fans on and off to determine which fan relates to which pipe. I realised a small breeze of air (very faint) from the problem pipe when the 2nd floor toilet flushes would be operated (please don’t laugh)? The other extractor fans generate a good extraction of air, so I can see why the moist will run straight through the vents. But this particular extractor is picking up moist from somewhere, but don’t know where? I first realised this problem roughly two years ago and have been living in this house for over 10 years now. I noticed the u-bend was very deep, so recently took my saw to it and reduced the depth roughly equal to the other extractors. As you can see through the other pics attached, all the pipes have a few twists in them, so not sure why only a faint breeze of air could be felt. But more to the point, what could this pipe relate too? I’m having to empty out the u-bend every week, and I’d say roughly 1.5 litres of water is deposited there, which is a pain in the back side! Appreciate any advice guys as always! Thanks Ash
Insulate all the pipes completely that are in use,corrugated pipe is slightly thinner than the grey, so colder allowing warm air to condensate back to water,also is corrugated pipe smooth on the inside & not ribbed, overall you layout is flawed. Could also fit a condensation trap on flexible pipe, to allow water to drain away.
Are you sure the pipe with breeze isn't the vent pipe for the toilet stack pipe, because the air you feel when toilet is flushed is being drawn in to equalise the pressure on the system.
Thanks KIAB. The flexi is also ribbed in the inside. What do you mean the layout is flawed? How should it be? As this is the original layout from when the house was constructed. Please explain what a toilet stack pipe is and where I can locate this? I still don't know why there is a third extractor pipe in the loft when it doesn't seem to be linked to any fan? I missing the point here? Thanks guys. Ash
Hi Ash Just a question regarding what you are calling things 1/ What part of the system are you calling the "u" bend? 2/ Where are the fans located (I'm presuming in the bathroom(s) itself?)
3/ You say "The extractor pipe closest to the wall in Pic 2 services the 2nd floor bathroom and the 1st floor shower room directly below it." does that mean there is one fan serving two rooms (and if so the fan will be located in the vent ductwork rather than in the room itself) If you want us to give you best advice then fully understanding the problem is first step Regards Russell
Hi Russell, thanks for taking interest in this! Adopting your numbering above; 1. The u-bend in my description refers to the dip you can see in the black flexi pipe. 2. Yes, each bathroom has its own fan. 3. The 1st floor and 2nd floor bathrooms are directly in line with each other. The extractor pipes leading from each bathroom (1st & 2nd floor) merge (atleast I thik they do) to one pipe that is visible in the loft, and then out through the roof. I say this based on some observations when I conduscted tests mentioned above. Hope i've answered your questions and made things a little clearer? Looking forward to your response. Thanks Ash
I think the problem is the design of your vents. Nice warm damp air is coming up the pipe from somewhere and getting to a nice cold piece of tube just under the roof. In this cold tube the water WILL condense out. You have a perfect condenser! It is unlikely insulation will have much effect, because the pipe will still get cold just under the roof, and there won't be enough heat energy in the little bit of extract air to keep the temp inside the pipe above the dew point. With a U bend in the pipe you will always have a water trap. Strange that this vent doesn't seem to connect to a fan. Can't answer that! Assuming the condensation isn't running back down the pipe into the bathrooms or somewhere else (and if it is that's a different problem), then the answer must be to get rid of the U bend. Had a quick look around and there is this http://www.ebay.co.uk/itm/100mm-extractor-fan-roof-vent-/272016644659 where the extract pipe goes straight down which will eliminate the U, and any condensate will go out on to the roof. There must be cheaper versions out there!!
Just one question before I go on, how do you know when the water collects? Where does it spill out from? Here you go the simple solution (maybe!) It will require a bit of "re-routing" the existing ducts but it would require the least amount of effort To be honest (and I am not a house building expert) I have never come across this type of installation before with such awful looking insulation round the duct and then to not continue the insulation up to the termination point, that's just plain lazy The problem you have is a recognised potential issue with moist warm air coming into contact with air below its dew point This product allows any collected condensation to be captured and then run to a point of discharge. The pipe running up to the exit terminal will need to be run vertically and the trap located at the bottom of the vertical section If you have a local soil pipe and want to discharge to that, you will need to install a method of making sure smells don't come up through the drain. My product hotun (sorry for the promotion) will allow condensation to pass through and stop smells coming back up. The alternative would be to push the pipe out of the roof space to discharge over a gutter (don't let them to just discharge to outside because they may be confused for overflows!) This comment "Here is the weird observation. When investigating the above, turning the fans on and off to determine which fan relates to which pipe. I realised a small breeze of air (very faint) from the problem pipe when the 2nd floor toilet flushes would be operated (please don’t laugh)?" Will have to be dealt with as a separate issue, plus what room is the problem duct coming from it is unclear in your post Speak to you soon Russell
Thanks Simon / Russ!! The problem I think lies in not being able to determine where this pipe leads to? I've accounted for all the fans, and surprised two fans merge into one extractor pipe with the problem pipe made redundant, but clearly not redundant because it's soaking up moist from somewhere! Need your expert tip guys to follow the pipe to see where it leads to, it goes out of sight immediately along the side of the house after it goes through the loft floor - don't think removing the flooring will help much as the pipes are consealed behind plaster boards. I'm thinking of chucking something down with possibly a string attached to it and listening for rattling noise as it goes down the pipe (not gonna win a noble prize at this rate!). Looking at the pictures, I don't think I can further reduce the U-bend, as the extractor pipe has to connect to the roof pipe which is always pointing down. @ Simon, I agree the product on ebay probably will resolve the issue, but may also leave me with a hole in my pocket... @ Russ - I am having to go up in to the loft every other week and phycially empty the collected water from the pipe, I remove the flexi from the roof end and empty in to a bucket. Thanks as always guys! Ash
Not sure if it has been mentioned, but is it possible that it is connected to any one of your sink/bath/shower waste outlets as a vent to help prevent syphoning of traps? That might explain the water build-up(steam from hot water waste). To test this, you could run hot water, and check at the same time with your flexipipe removed, if it is warm or steaming. Mr. HandyAndy - Really
Hey Handyandy, i'll give it a shot next time i'm up in the loft. One other question, what could have cuased this suddenly to prop up in the past few years when i've been living in this house for over 10 years and haven't experianced this before?
Those roof vents look very similar to mine. I had a problem with water in the pipes, after a lot of checking, some of it was coming from the outside. The external covers on the vents had a fairly significant moss growth on the upper side, when it rained, the moss soaked up the water from the roof and allowed it to run back down the pipe. Have a look (if you can) at the outside, it may explain why it's not happened before
I've had a few untouched spiderwebs in the pipe just beneath the roof, so guessing that rules that out?