Single brick heat loss quantity?

[Lieutenant Scott]

Does anyone know how much difference there is between the heat loss through single brick and double brick with cavity insulation?

I have double brick with cavity insulation, and my friend has single brick. When they come back from holiday, their house takes 48 hours to heat up from 5C to 20C. Mine takes a few hours! We both have a similar house with similar sized radiators, which all get piping hot, so I assume it's nothing to do with the boiler.

The only other thing I can think of is they have nothing behind the radiators to reflect the heat (silver foil?) - neither do I, but the double brick presumably helps here. I cannot understand where all the heat is going!

We both have similar loft insulation.

[Tim]

Really??? Go on, have a guess. That, or google "u values".

Tim

[Dave Liquorice]

Do you reaaly mean single brick ie 4 1/2" thick or a solid 9" brick wall ie tw brick widths thick. I suspect the latter as the former are not very strong...

A solid wall left to get cold will take a long time to heat back up. We made the mistake of switching the heating off here once when we went away. Never again it took 72 hours to be come comfortable again.

18" thick 15 x 20' solid stone wall runs through the middle of teh hous outerwalls are also solid stone...

[Lieutenant Scott]

I have a degree in Physics, I know all about u values. I just wondered if someone knew what they were for a typical single and double brick (with cavity foam) house?

[Lieutenant Scott]

I've not seen the house myself, they "thought" it was single brick. I can't see why it's so difficult to judge the width of the wall by looking through the window.

[John Williamson]

I'll just Google that for you, shall I?

you want and a bit more.

[ARWadsworth]

mouldy old dough.

[Lieutenant Scott]

Ahhh that's what I was after, thanks.

Bit difficult to add a cavity though.....

[ARWadsworth]

The river under your bridge is warmer than your neighbours.

[John Williamson]

Among other ways to get almost the same performance is to line the outside walls with insulating plasterboard. The stuff with 50mm of foam on it will bring a 9 inch wall up to roughly the same u value as a caity wall, while only losing about three inches off the room size. A bit fiddly in the kitchen and some bathrooms unless you're renovating them anyway, but not a major extra cost if you are.

You don't need to hack off the existing plaster, either, as you can fasten the insulating board to battens screwed to the wall. Or you can use other, similarly performing products on the exterior, subject to plannning rules. I rather think you'd need to get building control approval either way, but I could be wrong.

[Lieutenant Scott]

Thanks, I'll let them know. They would need permission to put up plasterboard INSIDE their house?!?

[Lieutenant Scott]

What the f*ck is wrong with morons like you? I come on here asking a perfectly normal question, and have been given a very helpful answer by someone more sensible and adult than yourself. It would appear that YOU are the troll around here.

[John Williamson]

IIRC, there are rules which say that *any* change to a thermal element is notifiable and must bring that element up to current standards. But, ICBW. It's been covered here in the past.

[Dave Liquorice]

So are you by not just fing googling it. Anyone with a physics degree (ie passed it if only by the skin of their teeth) ought to have enough nouse to use the tools available to them and work out the information they need from the results returned.

I can FFS with only a B in Engineering Science at A-level from 30 plus years ago.

[John Rumm]

Well a 9" brick wall (i.e. single brick) is 2.2.

The other would depend on the amount and type of insulation.

Could you clarify what you mean by double and single brick?

[John Rumm]

The term "single brick thick" means a 9" wall - i.e. two layers of bricks, making the wall the thickness of a single brick *lengthways*

[brass monkey]

Actually, I own a house with single-brick (4.5") walls, a typical old terrace around here (2 up, 2 down). Front and rear walls are 9", 'entry' walls and inter house walls are 4.5". You can hear the neighbours change their minds ;) I know it's true cos I chipped into a brick to fit a back-box, the brick fell out into the "entry" :D Lime mortar.

[Lieutenant Scott]

They did say they can actually hear their neighbours going to the toilet!

[Lieutenant Scott]

The opinion of people in the real world is always better.

[Lieutenant Scott]

I have two seperate 4.5" layers of brick, with foam inbetween. I've never seen a single brick house, but I assumed they were 4.5" thick, just one layer of bricks.