New build extension too cold
ne...@martech-scot.freeserve.co.uk
About 5 years ago we decided to put an extension on the side of the
house but it has not been a success as it is always too cold in winter
unless we spend a fortune on heating. It was built to current building
regs, with large blocks of foam in the sub-floor, insulation in the
walls, double glazed windows and two layers of insulation in the roof,
but for some reason we are loosing a lot of heat. It is traditional
build with brick outer, cinder block inner, dot and dab plaster board
internal and a pitched roof on top.
I had been hoping for a really cosy set of rooms (living room and
study) that would be built to need very little heating but it isn't
and consequently we only use the rooms when we have to rather than as
an extra integrated part of the house.
Does anybody have any ideas on what to do. My own suspicions are the
french windows weren't installed as well as they could and leak air
around the doors, also the dot and dab didn't include a solid line of
goop top and bottom so that air is free to flow from attic to under
the skirting boards.
Ash
<ne...@martech-scot.freeserve.co.uk> wrote in message
news:18d09f8c-b86e-4f75...@r41g2000yqm.googlegroups.com...
You say that the floor has "large blocks of foam in the sub-floor" so I
assume you've a solid floor? If you haven't then certainly if you've got dot
and dab plasterboard then cold air can move from attic to ground floor and
chill the walls. If this is your feeling you could try expanding foam and
drill holes along where the skirting board is and squirt the stuff inside to
seal any gaps. Along the top of the wall you could do the same and then
cover over with some nice coving.
The French doors .. are they double glazed? Try a match or a candle and
slowly move it around all the joints in the doors (best on a windy day) and
see if the flame flickers which will help locate any draughts. Be careful
with the naked flame.
I presume you've checked that the builder did put two layers of insulation
in the roof? Around the edges he will have left some ventilation gaps to
help the free movement of air around the loft ... did he leave too big a gap
and have you got too much of the ceiling un-insulated? It may be awkward to
get right into the edge of the roof so try a stick with a mirror on the end
or if you've got a mobile,camera or small digital video recorder try putting
it on the end of the stick and try filming the edge of the roof/ceiling.
Ash
ne...@martech-scot.freeserve.co.uk
> <n...@martech-scot.freeserve.co.uk> wrote in message
Okay, much the same ideas as myself. A candle isn't required, as it is
evident without it. I currently have clear tape around the door but
that is not the most elegant solution. The insulation was put in by me
and is double insulated as I said.
Bob Minchin
changing will undo the effect of lots of insulation.
Bon
Bob Minchin
ne...@martech-scot.freeserve.co.uk
> You have to stop the draughts. Even a relatively low volume of air
> changing will undo the effect of lots of insulation.
>
> Bon
>
If I'm going to be drilling holes around the room any thoughts on how
far between adjacent holes, it's going to be a lot of holes!
ARWadsworth
<ne...@martech-scot.freeserve.co.uk> wrote in message
news:18d09f8c-b86e-4f75...@r41g2000yqm.googlegroups.com...
Is the central heating correctly sized and tapped from the existing central
heating at an appropriate point?
If the radiators are tapped off the end of the existing central heating run
then you would need to balance all the radiators in the house to make the
ones in the extension work correctly with the ones in the rest of the house.
There should not be much air down coming down the dot and dab as the ceiling
boards should be close up to the wall and there should be loft insulation on
the top.
Adam
Ash
If I'm going to be drilling holes around the room any thoughts on how
far between adjacent holes, it's going to be a lot of holes!
If you're sure that you've got chilling of the walls by cold air from the
attic (doubtful if you've got a solid floor as there wont be any means for
the air to circulate) why not try drilling a hole somewhere not noticeable
and see if you do feel a draught coming out of the hole ... if not there's
no need to do the whole room/walls.
Are you sure that you've got a radiator that provides sufficient heat to
heat the room? If your radiator isn't producing sufficient heat to heat the
room then you may be under the misapprehension that the room is loosing heat
because it's not getting warm.
The B&Q website have a nice little BTU calculator to see what size radiator
you need. http://linkbee.com/F6HS
Have you thought about the exterior of the extension for heat loss? Is it on
an exposed corner of the house? Can you try and break the wind down by some
panel fencing, bushes or a garden shed? Presumably you extension will have 3
external walls which will all add to the heat loss in comparison to the
other rooms in your house which will normally have 2 external walls and two
internal walls.
Ash