Hi we have a modern house (16yrs old) which is fitted with internal soil pipes front and back, they pop up into the loft space and have been connected to tile air vents. The builders have bodged everything including these pipes, we only really noticed an issue with them when a damp patch appeared on the ceiling in the main bedroom. On inspection the soil pipes have been fitted with a solvent welded elbow which then has a short run of pipe and connected to flexible ducting, these joints have usefully been held together with insulation tape as you do. Over time water has been condensing in the ducting and then reaching a level where escapes out of the joint. 16yrs later it has corroded through the plasterboard. I have also posted a separate thread regarding condensation issues with the loft but as a side note water is condensating on the tiles in particular around the air vent and it has also been dripping down the ducting and pipe onto the rockwool and plasterboard so my issue is compounded. I have looked on google etc for help some people have fitted an air admittance valve, is this what I should do? will I need to remove the solvent welded elbows or can I weld a horizontal pipe then another elbow as room is tight to then have the valve in the correct orientation. thanks Neil
Sorry for mithering and for the long post anyone be able to point me in the right direction. Thanks in advance
If it's only the venting part that is causing the problem then remove it all, repair the roof where it used to exit, and fit an air admittance valve as high up as you can (either in the loft, below the loft, or even under the bath).
Hi Roger thanks for the response, I will buy the air admittance valves, would push fit do? Should I just cut the angle/elbow off? I am uncertain if the tile air vent is the cause of the condensation we do not have any other ventilation in the loft. On bad days the bitumen is covered in condensation and drips all over the loft. I am looking to get some roofing work done after a boiler replacement.
Just wondered if you had a bathroom extractor that was venting into the loft space and causing moist air to be in there. Long shot, but worth considering.