What to use to fill gaps round beams in a barn

[dottygamekeeper]

We live in a converted barn, it is double glazed and the windows do not seem to be draughty, but I do notice draughts coming in along the horizontal beam that runs all the way round at about hip height (has brick and rough plaster below it on the inside, brick on the outside - and above it, where the draught is coming from, there are vertical beams on the inside, rough plaster, and on the outside, weatherboarding). Any ideas for what to use to fill the gap between the beam and the plaster -that would be relatively unobtrusive (or could be painted) and would accommodate slight movement in the beam as it expands and contracts due to changes in temp and humidity.

How do other barn dwellers fill gaps that open up as the building moves? All suggestions welcome....

can water get into the gap?

No, no water comes in from the outside. I think that the weatherboarding on the outside is on some sort of battens, (and the weatherboarding overlaps the top of the brick plinth, so any water runs down the weather boards and drips off without making the plinth wet), then there is an airspace - a cavity, I suppose, then whatever the plastered walls are made of - and the cold air from the airspace comes in where the beams have shrunk/moved. In some places there is no gap, elsewhere it is several mm wide (and at roof/ceiling level where the ceiling beams meet the outside walls there are some very big gaps - these appear to be stuffed with wool and rags, or in some places some type of expanding foam filler). Hope that helps, and if you have any ideas, I would be very grateful, as we are getting through oil at a rate of knots at the moment... temp here -3 all day, now down to -7 (outside, not indoors!).

Also, piglet john, what are your thoughts as to whether it is cheaper to keep the heating on all the time, or have it on a timer + room stats? I have it on for 2 hours in the morning, then a few hours in the evening, all radiators have individual thermostats (but downstairs is all open plan), plus there are a couple of room stats (we have 2 boilers, one for each end of the barn)

your home is probably not suitable for cavity insulation. If the walls are plasterboard you could, if you feel like it, have it relined with Kingspan insulating plasterboard which has a high-efficiency rigid foam slab bonded to it, and can be skimmed over with plaster. The 1980's method was to batten out the walls and put mineral wool between the battens, then nail plasterboard over, which is not as good, but adequate.

A barn conversion is rather non-standard and if there are gaps between the skins I would hesitate to inject expanding foam as it may fall or expand into a gap that is supposed to breathe.

Instead of rags or newspaper, you could stuff the gaps with loft insulating quilt. You can get a white one, at twice the normal price, which is made of recycled soft drinks bottles, plastic not glass, and sheds no fibres. Otherwise I would use the mineral wool treated with Ecose to prevent it shedding dust or fibres, it is made by Knauf but sold under various brands. Look for the name Ecose on the wrapper, I wouldn't use anything else now as I am sensitive to dust. It is brown, not yellow and feels soft and silky. Having stuffed the gap you can use Silicone sealant on top, which will stick to clean dust-free surfaces, esecially if newly painted, and will squash and stretch a bit without cracking. Acrylic filler and decorators caulk are much cheaper and easier to apply neatly, but will crack with expansion and contraction.

Silicone is available in numerous colours but does not take paint well.

Is the roof very well insulated?

and...

heat loss is directly proportional to time x temperature difference. So if outside is 0C, heating the inside to 20C will lose twice as much heat as heating it to 10C. Keeping it at 20C for 24 hours will lose twice as much heat than as 12 hours.

There will be a delay in temperature rise when you turn the heating on, just as there is a delay in temperaturte drop when you turn it off, which will depend on the specific heat and mass of what's inside the heated envelope. In typical houses, you have the timer switch the heating on half an hour before you get up, or come home; and switch it off half an hour before you go to bed or come home. A modern house will only drop by a few degrees in a few hours, it will not get frosty inside.

Heating an empty house will make it more comfortable, but will certainly lose more energy and cost more.

Think of keeping a kettle simmering on the stove all day rather than boiling it each time you want to make tea. It will be losing heat all day.

expanding foam. you buy it in a can, spray in gaps and it sets. is great fun to use!

Thank you for the replies, am off to investigate the non shedding mineral wool - have always been a bit suspicious of the stuff that sheds nasty fibres.

Re roof insulation - there is some up there, but our 'loft' is actually very small in relation to our floor area because the upstairs rooms celings slope upwards and inwards so that the actual flat area between the roof and ceiling is only about 8 ft wide (and only about 5 ft high - I certainly can't stand up in there. I am therefore unsure whether adding more insulation will make much of a difference to the heat lost through the ceiling - any thoughts?

There should also be insulation between the sloping ceilings and the tiles. It depends on the space and the depth of the timbers. It is rather a job unless done when the roof or ceilings are being replaced.

Start with the easy bit.

I can't see the word "moths" on their website