AlwaysLearning

Cool in winter, hot in summer. No obvious cracks or damp patches in the external wall which led me to clutch at symptomless DG failure. I did try a cheap plug on thermal camera last year, but the quality of the image was so pants as to be near useless. Seriously tempted to buy a better one for my toy box though.

I'm absolutely out of ideas to solve this mystery ... W facing first floor bedroom is always colder in winter and hotter in summer. Approx 3m x 3m. S wall is an uninsulated party wall with nextdoor. But our bedroom on the E side that shares the party wall doesn't have heat problems. W wall was cavity insulated with blown mineral wool back in the 80s. W wall has a large DG window with no noticeable draughts. N wall is shared with another bedroom which doesn't have a temperature problem either. Room heated with a hot water rad with TRV. When the heating is running, the room is comfortable. Heating off, and the temp drops. Ceiling to the attic, 270mm insulation. Wooden floor with 170mm mineral wool insulation in the void and fully carpeted. One door and no noticeable draught under it. I've sealed the ends of the joists that sit in the party wall incase there's air movement there. I've sealed electrical sockets and the cable entry to the ceiling rose. I've sealed floor/skirting too. I'm out of easy ideas of where the heat is going or coming from. I'm grasping at: having the party cavity wall insulated though I've yet to find a local installer who'll touch party walls. Perhaps the 80s insulation wasn't done properly or has settled though the rest of the house is ok. DG units have utterly failed with whatever gas was used in the 2000 has leaked away but no condensation is in the gaps. Though all the other DG windows are ok. Or am I missing something really obvious? Is there an experiment I can do to rule in or out some factor?

They weren't routinely insulated in those days. Indeed, when the CWI was put in in the 80s, it was almost unheard of to insulate the party wall simply because they couldn't access it from outside and few homeowners were willing to have 1" holes drilled all over their inside walls.

SE wall is 4m x 2.4m SW wall is 3.25m x 2.4m with a window 2.35m x 1.2m

Right, drilled and inspected this morning. No insulation.

That sounds interesting. Could you tell me more about the phone please e.g. model and thermal features? I had a plug in IR attachment years ago as part of a project at work. It did the job but the IR sensor was 32 x 32 so next to useless except for close up.

I might have been swayed towards airtightness if the problem was more than one room. Don't forget this is a 70s house so any air tightness test would just show the entire house leaks The other bedroom faces the same way, is the same size and has the same sized window but doesn't have this issue so I'm struggling to point the finger of blame at that.

Thought about the trickle vent, so taped over it awhile back. Have to admit I've been tempted to buy a high spec IR camera from fleebay, use it, then sell it. Resisted the temptation so far since I know there's a high chance I'd put off selling it again and keep it "just in case". If I can't crack the problem over the next couple of months, I'll probably crack and get one for the helluvit. Can't comment on the quality of the CWI as it was before we bought this place. It's another reason, in my head at least, to buy that camera.

Plaster onto brick/block

No, I've not drilled in that room yet. Shifting furniture has put me off, ditto getting access to it for long enough. I'll just have to bite the bullet. I've no idea to what extent next door heat their bedrooms. They're recently retired so there's just the two of them knocking about it a 5 bed. I know they sleep in the end bedroom so quite probably have the heating turned down. However, their rooms being cool might not explain why my daughter's bedroom is so hot in the warmer months.

Apologies in advance for the length of this post, but I'm completely out of ideas .... Our house is a 1970s semi. We bought it 15+ years ago in a very dated state. I've been stop start renovating it ever since. My daughter's 1st floor bedroom is colder in the winter and hotter in the summer. I'm stuck for ideas where the problem might lie that would cause such a noticeable difference. When the heating is on, the room is ok, no different from the others. When the heating goes off, it cools more rapidly then the others. I'll go around the room, comparing it with others, what I've done and see if anyone can come up with anything. Ceiling. Plasterboard with pitched roof above it. Entire loft insulation was topped up after we moved in so there is no difference between this ceiling and any others on the 1st floor. SW wall. External with large DG window and cavity wall insulation. Out of curiosity, I drilled through the back of a socket and pushed a camera through so I know insulation is present. No evidence of failed DG units eg cracks or condensation. Window hinges replaced recently so there isn't a problem with the seals. Windows were replaced throughout the house perhaps 20 years ago in the usual slap dash manner. I've removed the UPVC strips used to hide the bodges and put frame sealant around all four edges so I can rule out air coming in around the window itself. Also inspected frame joints and beading and sealed any tiny leaks. Any remaining leaks must surely be too minor to make any significant temperature drop. Skirting to floor gap is sealed. There is a crack in the external brickwork near to the party wall which has been there since before we moved in. I've tried pushing a wire in at various places and it doesn't get very far. If it is letting air into the cavity, I wouldn't have thought it would be much, and not enough to cool the internal surface to make the room cold. NW wall. Internal stud. Small bedroom next to it doesn't have the same noticeable heat difference so I've ruled out this wall as being the problem. NE wall. Internal stud. Again, bedroom next to it doesn't feel any cooler even though it gets very little direct sunshine. SE wall. This is the party wall. It is plastered brick with an uninsulated cavity. Again, drilled a hole, put a camera through, and had a look. Also did the same inspection downstairs just to rule out the faint chance there was insulation but it had settled/slumped over the years. Going around with a lit candle I did find air blowing through the mains sockets so removed them and applied frame sealant to any gaps/holes in the pattress boxes. Skirting to wall gap is sealed. Floor. Carpet over underlay over 18mm floorboards. The floor void has 170mm rockwool which I fitted awhile back just to deaden the sound coming through from the lounge below. The ends of the floor joists run into the SE wall. They are not on joist hangers but embedded. For completeness, and in case they had shrunk or warped over the years to let air through from the cavity, I ran expanding foam over the joist/wall joint and floor/wall joint. No cracks in the bricks or mortar. Where the floor void runs under the NW stud wall, I've stuffed it with more insulation to minimise air flow. The bedroom behind that also shares the party wall (our side) doesn't have this problem. The other front bedroom which shares the SW external wall, is of a similar size, has an identical window, and is even over the garage, doesn't have this problem. After all of that, the room is still cool. If any of my actions has improved things, it's not been noticeable. It's like a window has been left open an inch. I'm stumped. Perhaps I'm too close to the problem and just can't see the blindingly obvious. Any suggestions or questions welcome.