Insulating a cold room

[codek]

Hi,

We have a room in our 1930s house which has 2 external walls. The outside is rendered and there is no cavity, i'm not entirely sure what the walls themselves are made of. brick/block etc.

Anyway this room is disproportionately cold compared to the rest of the house, and we want to move our daughter into it. so we need to sort out the temperature issues.

It has a relatively large radiator - but i think the problem is really the insulation. I've laid an extra layer of insulation in the loft above this room but it didnt make any difference.

The window is double glazed and doesnt have any draughts.

So i'm wondering if there is any way to boost the insulation in the walls? some sort of additional insulated board? I'd obviously be looking for maximum performance for minimum additional thickness. Any other ideas? My builder mentioned insulated plasterboard, but I want to be really sure that whatever solution we go for will actually work. Do i need to get some sort of insulation expert in to assess it?

Thanks! Dan

[Andrew Gabriel]

Buy (or borrow) an infra-red thermometer, and use it to find the temperature of all the walls/floor/ceiling/doors/windows. To a first approximation, the coldest ones are where the most heat is being lost, and the ones you should attempt to reduce the loss with insulation. The window is likely to always be the worst, but it hopefully isn't a large proportion of the surface area of all the external walls and ceilings, and if you can fix the others, the window alone won't matter.o

It may be that the radiator size was never properly calculated. It's all too common for a small room to get a small radaitor and a large one to get a large radiator, without taking into account the actual heat losses, which for a small corner upstairs room, are going to be significantly bigger than the size of the room alone would suggest.

What's the condition of the external rendering? If it's on it's last legs, you might consider ripping it off, fitting external insulating board, and then rendering over that. In many ways, external insulation can be the best, and the reason it can't be done is that it would damage external features of the house, but if it's already rendered, that might not be an issue.

Failing than, loft insulation as you've done, and then insulating the walls inside as you suggested above.

Does the room have a fireplace with a flue still open?

Make sure the radiator isn't blocked with cobwebs behind it, inbetween panels, or in the vertical air flutes.

[stuart noble]

I had a similar problem about 30 years ago when my 10 year old son moved into his own room. I lined the whole thing in cork tiles, which was surprisingly effective given the modest thickness, plus of course it became one huge notice board. Marcel Proust lived in a cork lined room

[The Natural Philosopher]

heavy drinker?

[Lieutenant Scott]

Tell your daughter to put up with the cold. It'll boost her immune system.

[polygonum]

Do you have any evidence for that? And how do you measure the boostedness (or otherwise) of an immune system?

[Lieutenant Scott]

Research has been done, google it.

It's also good for burning calories. I like to eat. A lot. And high calorie foods like chocolate. People don't understand why I'm not fat. I never wear warm clothes, I swim outdoors all year round, and I only use heating to prevent frost damage.

[meow2222]

You've insulated the loft. Presumably the room below is heated so no loss there. That leaves windows, draughts and walls.

Windows: Usually the biggest loss. Adding a 3rd layer in framed glass, acrylic or plastic film would reduce losses.

Walls: I'm not clear how you can know it has no cavity without knowing what material is used. Options are:

1. CWI is the best option if it does turn out to have a cavity
2. Exterior insulation under render is the next best bet if already rendered
3. Interior insulation board is the last option, typically used where exterior character rules out render. PIR board then plasterboard is cheaper, but wastes half an inch depth. Hard faced PIR board costs more but doesn't waste any space.

There are other options occasionally used, but those are the 3 to look at.

NT

[ARW]

Some people do understand. It is because you are mentally retarded.

[Jim K]

and type excessive amounts of bollocks?

Jim K

[Lieutenant Scott]

So because I can do something you can't, I'm a retard? More like you're a pussy that spends a fortune on heating.

[ARW]

I am sure that you can do lots of things I cannot do.

[Lieutenant Scott]

[taps foot]

[Jim K]

rhythmically or retardedly? ;>) Jim K

[Lieutenant Scott]

Unpatiently.

[ARW]

against your forehead while asking for tomato ketchup on your cornflakes.

[Danny Colyer]

I've been contemplating this for a while (I also live in a 1930s house with rendered walls and no wall cavity).

Does anyone have a rough idea what sort of cost I'd be looking at to have the rendering stripped, external insulation added and new rendering done on a 4 bed end-terrace house?

[meow2222]

Render removal: SDS drill =A3100, chisel bits =A37 at aldi Insulation: google celotex/kingspan seconds. IIRC BR requires about 3". Als= o insulation clips. Render: EML, preferably in SS, SS screws, cement, lime, sand, 1:1:6

NT

[Danny Colyer]

insulation clips.

Plus scaffolding costs, cost of time off work.

Thanks, but this isn't a job I'd contemplate doing myself.

[robgraham]

there. That leaves windows, draughts and walls.

rylic or plastic film would reduce losses.

at material is used. Options are:

erior character rules out render. PIR board then plasterboard is cheaper, b= ut wastes half an inch depth. Hard faced PIR board costs more but doesn't w= aste any space.

I think the OP needs to take on board what has been said here but also consider quite why this room, with its two external walls, is so cold. If it is any normal house then nearly all the larger rooms will have two external walls !! There must be other rooms in the house that are similarly configured so there must be some specific reason why he considers this room worse than the others, and see if he can address that.

Rob