Best log burner for heat

[Guest Gimlet]

7 hours ago, Steven P said:

Different houses, locations, insulations, firing regimes and definitions of 'really cold', my 5kw stove is doing OK, stop fuelling it at supper time this week, and it is 5 to 6 degrees outside. Really cold the other week, -7 to -10 and it struggled we had to use the electric heater.

 

 

 

Looking back at this, you might cost up the work to get a larger stove, and any changes, decorating and so on to the fireplace, might be cheaper to upgrade all the insulation, same effect of a warmer house with ongoing energy savings? Not sure if you have a suspended floor - we insulated under that and it made a noticeable difference. Cost about £2 a sq m, DIY 100m rock wool, next job is insulating under the eves and not just the ceiling joists and I'd guess will be about £3 a sq m (cause it slopes, costs more) for 100mm rockwool (probably go better and thicker up there next though)

Much better, if you can, to insulate between the rafters in a roof space using PIR (Celotex etc) foam board. 

Mineral wool is highly absorbent and soaks up ambient moisture. PIR is more or less impervious and does not. The board shouldn't be pushed right to the back of the rafter so it touches the sarking felt, but kept and inch back for air circulation with an inch or so gap at the ridge and the eaves to allow moist air to escape through vent tiles/slates in the roof. If the roof has a gable end, an airbrick in the end wall of the roof space helps as well. 

Insulating between the rafters instead of on top of the ceiling joists means you have the same climate in the roof space as you have in the rest of the house and as long as the loft is ventilated it makes a vast improvement to heat retention and reduces humidity throughout the whole house. 

Needless to say, this only works properly if you've got breathable sarking membrane under your roof battens. If you've got non-breathable bitumen felt you need two lines of tile vents six feet apart, one just below the ridge line and another just above the eaves, both sides.

Edited February 2, 2023 by Gimlet

[Steven P]

Cheers Gimlet, I should have asked here for advice first - tried the insulation manufactures and retailers (the experts) and.. nothing. Should have known better