Attic insulation

Mon 4 Jan 2021, 14:11

Dear all,

thank you so much for your helpful replies. As things are a bit slow to progress due to Covid I haven't got any further with this problem. I will look into a possible problem with the pipes and check with the roofer about the breathable membrane.

Yes, it is hugely frustrating!

Kati

Thu 31 Dec 2020, 08:46

Just thinking about the roof vents- when you say you had a new roof do you mean that the old membrane was replaced by a new breathable membrane or that the tiles were replaced but the  old membrane left on ( seems unlikely they would have done this though?In which case roof vents would probably not be as helpful as the new membranes ought to breathe without extra vents). Checking the eaves for blockage is a simple thing to do and would at least help the problem. Whether the hot pipe is compounding the problem I'm not sure, perhaps it could be clad more thickly (though that is just speculation)? 

Wed 30 Dec 2020, 22:56

You may need to get some roof vents put in. I have a very similar problem with condensation and my surveyor recommended to do this. The eaves may  also be blocked by the insulation so check that. You basically need an intake of air and somewhere for it to flow through to and escape otherwise  the water in the air condenses and drips off. There are a variety of vents, I am getting 6 tile vents, 2 on the bottom and 1 above on both sides.  If it is left for a long time it can cause mould and damage to the wooden rafters, so it is worth  dealing with properly in due course. Of course this applies to my particular circumstances and you may wish to get some unbiased advice, though it seems like what the roofers said makes sense (though I am not a professional/ expert).It must be frustrating to have spent a lot of money on a new roof and for another issue to crop up! 

Mon 28 Dec 2020, 23:10

HI Kati.

The more you insulate at ceiling level the colder the roofspace will be and there will be an increased risk of condensation, particularly if there is an old fashioned impermeable membrane above the rafters in which case condensation could run down the inside surface of the membrane and show at the eaves. If a permeable membrane has been used and installed properly there should not be a problem. The pipe however could get very cold and if it is not lagged it could be subject to freezing damage and could certainly attract condensation. Or there could be a leak in the pipe.

Mon 28 Dec 2020, 11:14

This is a question of basic building physics where hot air meets cold air, and the need to preserve appropriate ventilation when undertaking refurbishment.  It seems surprising that any hot water pipe would be going into the roof space, and if it really was essential for some reason, that it should not be heavily insulated.  However, I'm not a technical expert.  Fortunately Charlbury is home to CosyHomes, an Oxfordshire-wide project to ensure the quality refurbishment of all properties following the preparation of a whole-house plan.  It may be that one of their experts - called Retrofit Coordinators - will see this and help. I suspect there would have to be a site visit. 

Mon 28 Dec 2020, 10:11

Sun 27 Dec 2020, 23:15

Could it be your loft hatch is not tight closing? Therefore, warm air from the house getting into the loft and causing condensation. It’s something I’ve read about as it’s on my list of to do jobs.

Sun 27 Dec 2020, 15:41

Hi Käti,

Condensation is caused when warm air meets a cold surface.

I find it hard to believe that your problem is due to condensation. It is more likely due to a loose junction on one of your water pipes (maybe a pipe disturbed by whoever put the insulation in)

I suggest you ask a plumber to have a look at it when you can 

Paddy 

Sun 27 Dec 2020, 13:07

I have spent a lot of money on a new roof and had the attic space insulated at the same time. The effect is fantastic - the temperature is very stable and almost as good as below in the living room! But! I now have a constant drip off one place in the attic ceiling. The roofers think it is condensation building up in the space between the insulation and the roof. There is a hot water pipe going into that space, which might be the cause of the condensation.

Has anyone had similar experiences after insulating the attic? How did you solve the problem? I would appreciate your advice. Kati