cold kitchen extension, cheap insulation solution required

garlad

Hi,
Moved into the house a few years back. Didnt realise there was no insulation in kitchen extension (square shape at the back of the house, average size) at the time.
Last year we got a new flat roof put on, and insulated that. Made a big difference.
Would love to insulate the walls from the inside, but to do this would have to take out the fitted kitchen and appliances, etc.
Cant inject the walls, coz they are the wrong type of bricks apparently.
Kitchen has lino on raised wodden floor (about 3-4 feet off the ground). Was thinking if I could under the floor, maybe I could do something down there to stop some cold coming into the kitchen.
Worth it? Tips? Anything else I could try?
Eventually we will be knocking this and rebuilding a bigger one, so dont want to spend a fortune.
Cheers

RKQ

garlad wrote: »

Hi,
Kitchen has lino on raised wodden floor (about 3-4 feet off the ground). Was thinking if I could under the floor, maybe I could do something down there to stop some cold coming into the kitchen.
Worth it? Tips? Anything else I could try?
Eventually we will be knocking this and rebuilding a bigger one, so dont want to spend a fortune.
Cheers

There isn't much you can do cheaply, without removing the kitchen units, especially if you plan to demolish & rebuild the extension at a later date. Maybe its time to consider rebuilding this year?

There is a Gov grant for external (& internal) dry lining insulation, but external insulation is expensive to install, as requires exterior walls to be re-plastered, gutters, window cills, downpipes etc to be altered.

You could remove the timber floor & joists, lay a damp-proof-membrane, 60mm - 120mm foil backed Kingspan or similar floor insulation and 150mm conc slab.

Cheapest quickfix might be to lift floorboards, install fibreglass quilt between joists supported on chicken wire /netting. Re-lay floorboards or sheets of plywood. Of course kitchen units would have to be removed for this, unless floor is covered in chipboard or ply.

garlad

RKQ wrote: »

Maybe its time to consider rebuilding this year?

Wish I could afford it!
Thanks for the reply.
Meant to say the floor under lino is ply. A hole was cut in it before to get gas pipes to the gas hob, so could probably widen this hole.
Do you think any underneath insulation will make a difference?

RKQ

garlad wrote: »

Meant to say the floor under lino is ply. A hole was cut in it before to get gas pipes to the gas hob, so could probably widen this hole.
Do you think any underneath insulation will make a difference?

How deep is the foor void - top of subfloor to top of ply?
If the timber joists are supported on dwarf walls, then its worth insulating the floor joist with 100-150mm fibre glass. Ensure vents to floor are clear, allowing good air movement - preventing dry rot.

It should be possible to cut ply close to base of units with a circular saw. You should be able to reach in unit the units to staple netting to joists to support fibre glass insulation. Fit it tightly between joist to prevent draught.

Its a DIY job, depending on skill & should get noticable results without costing much. 100mm fibre glass will be worth it. Original Ply should be re-used.

garlad

RKQ wrote: »

How deep is the foor void - top of subfloor to top of ply?

from what I remember, under lino is ply, which sits on joists. then a gap to ground of about 3 feet.
Is that what you mean?
Like the idea of stapling chicken wire, never would have thought of that.
When cutting through ply, how do you not cut through joists? Or is it that you do, but only a little bit, and not enough to weaken them?

RKQ

garlad wrote: »

When cutting through ply, how do you not cut through joists? Or is it that you do, but only a little bit, and not enough to weaken them?

Set depth on Circular saw to depth of ply +1mm. Should be able to cut ply only. 3ft deep floor is fine, should be no problem to install fibre glass. Good luck.

garlad

Thanks for help!