Initial heating of a previously unoccupied house

Det Somerset

Bought a large 2500 sq ft bungalow last year. It was an old house and had been unoccupied for maybe 3-5 years. I had major renovations done to it, including a new heating system and radiators and as much extra insulation as I could afford. We moved in just before xmas and generally have found the house very cold in comparison to the 3 bed semi we had been living in. There, the house might drop in temperature to 13/14 degrees overnight, but 2 hrs with the heating on would raise the temperature over 18/19 degrees and would hold there reasonably well. In this new house, the house can drop to a natural temperature of about 11 or 12 degrees overnight and it takes about an hour of heating to raise the temperature 1 degree but it almost drops at the same rate when the heating is turned off.

The builders have been telling us that this is to be expected when moving into a house that has been unoccupied for years and was exposed to cold temperatures during renovation. They say that living in it for a year and having a summer behind us will mean the house will be warmer next winter. Is this true? I don't really see how that works. I would have thought having been in the house for 6 weeks, our current state of affairs is what we have to deal with going forward, but they seem to be suggesting that the natural house temperature will be higher next winter. If it did rise a degree or two it would make a big difference as it would take less time and money to heat the house to a more comfortable temperature. I just don't understand how that will happen. When we first moved in, the house temperature (pre heating) was 9 degrees. That to me is the 'unoccupied' temperature and surely the bump up to 11/12 degrees we have seen since is the 'occupied' temperature that will remain the same going forward. Am I missing something or are they telling fibs? I'd prefer to know what to expect rather than have a false hope that things are going to improve if they aren't going to.

4Sticks

The fabric of the house will be relatively damp now and will remain so for some time causing a drag on temperatures. Your builders are not lying to you the house will dry out further over the course of a year and will feel better next year.

Det Somerset

4Sticks wrote: »

The fabric of the house will be relatively damp now and will remain so for some time causing a drag on temperatures. Your builders are not lying to you the house will dry out further over the course of a year and will feel better next year.

That's interesting, thanks. By 'fabric', do you mean the foundation and block work? Realistically do you think we would see a rise of a couple of degrees or is that too optimistic? I'd love to read more about this but I can't find anything online about it.

Also would you think it's worthwhile to have the heating on more than we would like to in order to raise the temperature sufficiently or would you think this would be a waste of money if the house is indeed damp after being unoccupied and needs a more gradual drying out process?

4Sticks

Just roll with it. By fabric I mean floorslab and walls mostly , but timbers too to a lesser extent. All take longer to heat up when relatively damp. I say relatively damp so as not alarm you you - I mean relative to next year when the moisture content will have reduced. If you attempt to dry the house too fast your risk warping doors + skirtings , cracking plasterboard / nails popping etc.

Det Somerset

4Sticks wrote: »

Just roll with it. By fabric I mean floorslab and walls mostly , but timbers too to a lesser extent. All take longer to heat up when relatively damp. I say relatively damp so as not alarm you you - I mean relative to next year when the moisture content will have reduced. If you attempt to dry the house too fast your risk warping doors + skirtings , cracking plasterboard / nails popping etc.

Thanks for this. We have already been in for 7 weeks or so with heating used sparingly so I would be hoping we haven't been close to drying the house too fast so far. We just want to get more heat into the rooms at this stage as we are seeing a lot of condensation despite suitable ventilation and insulation, and I think it's because the temperature of those rooms are under 12/13 degrees about 21 hrs a day and rarely rise above 15 degrees the rest of the time with the heating being used so sparingly.

4Sticks

You need to heat the house more than this. :eek: You will get mould soon if not already. you have come nowhere close to drying the house out too fast

Det Somerset

4Sticks wrote: »

You need to heat the house more than this. :eek: You will get mould soon if not already. you have come nowhere close to drying the house out too fast

This is exactly where we are. We have noted some mould appearing in the last two weeks or so. Initially the builders suggested vents but they are now in and it doesn't appear to have made a difference. Due to the renovation costs we actually ran out of money over xmas and so we didn't have a lot of oil and we used it sparingly. We got paid a couple of days ago and we purchased more oil and it's been in my intention to have the heating on more often now to see if that helps the mould situation. Based on your reaction that is definitely what is required. We had it on for four hours straight when we were home last night and the temperatures got up to nearly 18 degrees. Would you see this as the bare minimum? Do we need it on even more than this? What would you recommend? We are still not financially out of the woods so we don't want to burn through too much oil unless it's necessary. I'm also looking at getting some condensation traps for the rooms that seem to be worst affected. Any use or a waste of time?

4Sticks

Crappy situation. Prioritize rooms you actually occupy and top of that list must be bedrooms - make sure they at at min 18 degrees for min 18 hours I would suggest. Cliche but true health is wealth. You must not tolerate mould here at all. Then manage the other rooms by twice daily removing ( toweling ) condensation and mould . Not ideal but needs must.

Det Somerset

4Sticks wrote: »

Crappy situation. Prioritize rooms you actually occupy and top of that list must be bedrooms - make sure they at at min 18 degrees for min 18 hours I would suggest. Cliche but true health is wealth. You must not tolerate mould here at all. Then manage the other rooms by twice daily removing ( toweling ) condensation and mould . Not ideal but needs must.

Thanks. It's really helpful to get specific instructions like this from someone who clearly knows what they are talking about. Builders have been vague and inconsistent in their recommendations. We'll look to work towards what you are saying here and hopefully this will do the trick.

One final question (at this point anyway) we have a dehumidifier which we tried using in the past but I've since read that a dehumidifier does nothing for a cold damp room and we needed to raise the room temperature instead. Would you agree that the dehumidifier is of little use to us currently, or could it be used in conjunction with the other tactics we are going to use?

4Sticks

Ditch the dehumidifier and consider one or two electric blow heaters. Try using the boiler for min background heat topped up with the elec for.evening comfort heating.Don't entertainm super Ser gas bottle type heaters they will add to moisture loading.

Det Somerset

4Sticks wrote: »

Ditch the dehumidifier and consider one or two electric blow heaters. Try using the boiler for min background heat topped up with the elec for.evening comfort heating.Don't entertainm super Ser gas bottle type heaters they will add to moisture loading.

Thanks again. I really appreciate the advice here.

st1979

Det Somerset wrote: »

Thanks again. I really appreciate the advice here.

Cold damp room may be no good for dehumidifier but you are warming your rooms so surely use both together. This is what I do to dry out a house. Am doing it at present on a granny flat I am wanting to finish.

Det Somerset

st1979 wrote: »

Cold damp room may be no good for dehumidifier but you are warming your rooms so surely use both together. This is what I do to dry out a house. Am doing it at present on a granny flat I am wanting to finish.

I think the problem was we were never heating the room sufficiently. Instead we had the dehumidifier running mostly when the room temperature was around 12 degrees and then it's ineffective (as I've recently learned). I think we are going to focus on heating the room suitably initially and re-assess at that point.

4Sticks

Det Somerset wrote: »

I think the problem was we were never heating the room sufficiently.

Yes.