Under floor insulation

[Alison556]

I hope I'm putting this question in the right section - but please don't shoot me if I've not

We have very deep foundations under our house. I've never been under myself (don't like enclosed spaces or spiders) but reports are that it's anything between 10 and 15 feet deep!

When it's very windy, it's bloomin freezing in the house and it does get very cold in general.

Would insulating under the floor actually help much? And I'm imagining that it would be easy enough to do from underneath. What would be the best kind of insulation - fibreglass or polystyrene?

Next question - and I'm sorry if this sounds really dim......but how do you know if you can get cavity wall insulation?

We had to get a couple of the airbricks replaced and while the guy was doing it, I was generally being nosey. From what I can see, the outside walls are brick and there is a cavity, but it doesn't seem to be brick on the inside - when the air vent came out, you could actually see the plaster from the internal wall through the gap.

 

[aaberdeen]

Hello,

Insulating under the floor will help especially if there are any gaps in the floor boards.

I put a new French pine floor down in my dinning room and was worried about it being cold underfoot without a carpet. So I put a space age silver foil type insulation (can’t remember brand name) directly beneath it and the room in now toasty.

If you’re doing it from below, use slab insulation and netting to hold it hammock stile between the joists.

This PDF has more details:
http://www.wickes.co.uk/content/ebiz/wickes/resources/images/gil/32.pdf

Don’t block the air brick though!

Hope this helps

 

[jmac80]

id be making another room out of that space

 

[Alison556]

Hello,

Insulating under the floor will help especially if there are any gaps in the floor boards.

I put a new French pine floor down in my dinning room and was worried about it being cold underfoot without a carpet. So I put a space age silver foil type insulation (can’t remember brand name) directly beneath it and the room in now toasty.

If you’re doing it from below, use slab insulation and netting to hold it hammock stile between the joists.

This PDF has more details:
http://www.wickes.co.uk/content/ebiz/wickes/resources/images/gil/32.pdf

Don’t block the air brick though!

Hope this helps

Thanks for that. I wasn't sure if insulating under the floor would make a huge difference. Hope it does though, cos even though I have the heating on and the room is toasty just now, my bloomin feet are freezing.

Just got to find a willing person to go under the floor to do it! Do you reckon that any kind of insulating company would do underfloor (if they do lofts and cavity?).

id be making another room out of that space

That's normally the first thing that anybody that's been under the floor says. They tell me I can have a complete additional house under there. I would love to see it, but I couldn't bring myself to go into the little crawl tunnel that you have to go into first before you get under the foundations. I have peered down a hole when the floorboards were up. It's very deep, very dark but very dry - the floor was tanked a couple of years ago. Any additional room would have to just have a back aspect though. The house is built on a hill and although the founds are pretty even underneath (I think), there's not a lot of wall at the front of the house, but a huge wall at the back.

One day, perhaps, I might do it.

But I gotta get rid of the draughts first.

Now, about my cavity.....................

 

[jeds]

Insulating floor and cavity walls is very efficient and you should be able to recover the cost within about 5 years. Plus of course you benefit from being a bit warmer.

My advice is get a couple of quotes from reputable companies for both jobs and take it from there.

You should be able to find local installers from the NIA website.

http://www.nationalinsulationassociation.org.uk/housholder/householder-nia.html

 

[Alison556]

Brilliant. Thank you. To be honest, I didn't know where to start looking for someone. Like you say, you want somebody reputable.

 

[Bespoke]

Hi

I did this drawing for another member regarding the replacement of floor boards it just may be of help. If you use this method I would go for an insulation product going buy the name of Kingspan


http://www.alanwakefield.co.uk/Alison556.pdf

http://bmdinsulation.com/index.htm

One last thought; If you go to your local planning or trading standards they may be able to point you in the direction of a good tradesman to do the job.

 

[Alison556]

Brilliant thank you. That's exactly the type of method I thought of using (apart from the batons - I was thinking more of hammering some nails in to use as support pins!!)

I'll look at the Kingspan.

And I'll also find out about someone to install it.

Do you reckon you get grants for under floor insulation? I've seen them for cavity wall and loft....................hmm something to find out about.

 

[Ken70]

I used battens, Allison, when doing it earlier in the year, tho I was working from the top.
Tried for a grant from Energy Savings Trust, no go but things are looking up. Might be worth trying.
Don't put a vacuum barrier on the cold side of your insulation.Has to be between floorboards and joists.