I'm really hoping someone might be able to help us shed light on why a bedroom that was previously naturally cosy is now really cold! We had some building work carried out recently that included putting a new ceiling up in our back bedroom, which is beneath a flat roof that's in great condition (we're in a Victorian semi-detached, if that helps). The walls of that room were also re-skimmed and a disused chimney breast was hollowed out and an MDF cupboard installed inside. Directly below this room is the kitchen and we had the ceiling replaced in there too because an RSJ was inserted to accommodate a structural change, but the space between the kitchen ceiling and the floorboards in the bedroom above was insulated. The bedroom floor is carpeted. Now, however, the bedroom that was previously so cosy we rarely put the radiator on even in winter is now noticeably cold. Like, much, much colder. We're putting the heating on to take the chill off but it's barely making a difference. It's only September and when the temp really drops in winter it's going to be unusable. Our builder is coming back tomorrow to discuss the matter. We had a brilliant experience with him, so I don't doubt he's going to want to sort it. I would just like some suggestions of what might be causing it before our meeting, as I'm becoming very worried about it. Thanks!
When they hollowed out the disused chimney breast to make your 'built-in cupboard', what steps did they take to avoid heat loss up the chimney. Check in that area for draughts, any signs of cold, etc. For sure if it is colder than the rest of the room condensation will occur and you will end up with mould growing on the walls nearby or in the MDF cupboard. I could be completely wrong, but with what we've been told, that's my best guess.
When I went in this morning I did think it was colder around the cupboard but wasn't sure if my mind was playing tricks on me! The plasterwork on the chimney breast is definitely colder to the touch than the other walls. Before, it was boarded out and I think there was insulation in there. I don't know what they did to replace the insulation, but I'll check. Thanks!
There are a lot of conflicting opinions about how to deal with disused fireplaces and chimney breasts. If it were mine, I'd make sure that as much insulation is pushed into the old chimneys as possible. I'd also make sire the tops of the chimneys were completely blocked off as sealed with bitumen. I know others will say that they should breath, but I've never found the need for that.
I really hope it is this, because it will be easy to rectify! I've been worried it was the ceiling space that's not been insulated adequately.
Would have put some insulation above the cupboard,something like a 100mm insulaton rigid/batt, as mdf is most likely 18mm. And flat roof most likely a cold roof design (insulation between joists) ,& not a warm roof (insulation on top of roof) designed for a habitable room.
Should I be worried about it being a cold roof design, Kiab? The thing is, I know when they replaced the ceiling in the bedroom they put new insulation in, so it shouldn't be any colder than before. The room was never chilly before, so the ceiling can't have been the problem. Definitely going to get the builder to have another look at the cupboard! It was 18mm MDF they used.
What about the insulation between the kitchen and the bedroom? I assume there wasn't any before and I wonder if by insulating that space you've simply lost the transferred heat from the kitchen?
"Directly below this room is the kitchen and we had the ceiling replaced in there too because an RSJ was inserted to accommodate a structural change, but the space between the kitchen ceiling and the floorboards in the bedroom above was insulated." Are you saying that the kitchen ceiling-to-bedroom floor void has now been insulated? If so, is it likely that your bedroom was previously warmed by the kitchen below - a crude form of underfloor heating?
Yes, they put a layer of thermal Rockwool between kitchen ceiling joists and bedroom floorboards for sound insulation.
So, the kitchen was previously heated by radiators (and cooking), which means the hot air rises quickly to the ceiling, and the kitchen ceiling-to-bedroom floor didn't previously have any insulation? That could well be the reason. You now have UFH in the kitchen which is an excellent heating method as it's much cooler but still manages to heat where it's needed - at a lower level. The heat from the UFH which ends up at the ceiling will be MUCH cooler than before with rads. Add to that the insulation that's been stuffed in there... It is usually a good idea to add insulation between floors because many floor voids are open to the wall cavities or house eaves so have cold air flying along them which would take away any useful heat coming from the ceiling below, but it sounds as tho' - in your case - the kitchen heat was getting through and giving your bedroom its own UFH If this is the cause - and it seems likely - console yourself that you are not losing anything; your bedroom was being partially heated by the kitchen below, so the kitchen was losing lots of heat that you were still paying for. It's a shame you didn't have insulated boards put on your outside bedrooms walls and disused chimney as part of your refurb as I think this would have made a noticeable difference to the room's insulation level. I presume the bedroom's ceiling is now well insulated? If it turns out that the bedroom is hard to heat, you'll just need a bigger rad in there, or a second one.
One thing you could use to trace any draughts or air movement is incense sticks. Get yourself a few of the ones that look like sparklers and use the smoke to trace the airflow in the bedroom. You may find that there are a few gaps around the wardrobe where air is going up the chimney. You have two problems to solve - keeping the bedroom warm and also the remains of the chimney insulated
Will definitely try the incense trick, thanks! Allsorts, should we be removing the insulation between the floor and the kitchen ceiling?? Hopefully sorting out the chimney insulation will help a lot. The irony is, we had to have a small radiator put in the room because the door moved position. Our plumber said we might need a bigger one but we said the room is usually so cosy even in winter that the heating is rarely on... Regretting that now!
I've just stood in the room for a bit and it's definitely a draughty cold, as if air's getting in somewhere, as opposed to just a bit chilly because the heating's not on, if that makes sense! The cold air seems worse at floor level too.
I wouldn't remove the insulation. That insulation is doing the job it should be doing. AND the heat at your kitchen's ceiling will no longer be as warm/hot as it was before because you now have UFH down there - a wise choice. So fix this the way it should be fixed - by adding a suitably-sized rad in the bedroom. And this rad should be off - or turned right down - for most of the day anyway. (Assuming a cold bridge hasn't been created at the old chimney breast. I suspect strongly - since these builders seem to be a competent bunch - that the 'cold' chimney breast is a red herring. But - yes - do check for obvious draughts all the same.) BSpark, I'm pretty sure we've arrived at the actual cause. There is only one proper solution.
Most likely draught down chimney finding it's way in around cupboard,which loosely fits opening, & trimmed around edge to hide gaps.
Try Sos's trick with smoke. But a cold surface will create its own 'draughts' - air currents - just as a warm radiator would. I'm not saying that there isn't a draught there - I cannot possibly know. But what I am saying is that we have found the almost certain reason why your bedroom was so warm before - it was stealing heat! And you were paying for this - it wasn't free. You removed your bedrooms thieving 'UFH' AND fitted a smaller rad! And it's now cold! Well, d'ur...