How Much (Roughly)?

[securespark]

Proposed floor insulation and plaster boarding and plastering

Room size 5.7 metres long x 3 metres wide
Includes confirmation survey
Take up the existing floor boards,remove from site and replace with new suitable mould resistant tongue and groove 22mm boards
Take down existing en suite partition wall and timbers etc and remove from site
Fully insulate the floor in between the joist with 100mm or if not possible 75mm celotex or similar heat saving rigid insulation boards
Seal any gaps in the corners
Re build the en-suite stud wall If new door and frame required this would be extra depending on door and Furniture etc
Supply and fit insulated plasterboard 25mm insulation plus 12.5mm plasterboard total depth 37mm (standard plasterboard would be £215 less )
Re plaster all walls and ceiling and also around the reveals of the windows were necessary
Supply and fit new skirting boards all round
Supply and fit new coving all round
Large skip included
All the work carried out by skilled joiners and plasterers and we would envisage it to take around 12/14 days in total with a minimum of 2 men per day on site
fully Project managed

Also, they mention insulation-backed PB....is there any need with a warm roof above?

Will the use of IPB a) do nothing or b) make the room warmer or c) create condensation?

Thanks, guys.

 

[phatboy]

Sounds very generous on time, I'd think 2 guys could do that in 5-7 working days?!

 

[cdbe]

No Idea, but I reckon you'd start saving money on your heating bills in around 2150.

 

[23vc]

Deffo sounds like a lot of days. What’s with the warm roof insulated plasterboard thing?

 

[securespark]

No Idea, but I reckon you'd start saving money on your heating bills in around 2150.

You mean it won't warm the room up?
Basically, this is a bedroom over an unheated garage. We are having a new warm roof over and I have been told there should be Celotex under the floor too.

23vc: I dunno. will it make the room warmer, be utterly pointless, or even worse, be detrimental?

 

[23vc]

What do you mean by warm roof above it? A loft space with loft insulation above the ceiling? If so and if the insulation is at least say 300mm of mineral wool type stuff then you don’t need the insulated plasterboard

 

[cdbe]

You mean it won't warm the room up?
Basically, this is a bedroom over an unheated garage. We are having a new warm roof over and I have been told there should be Celotex under the floor too.

It will reduce heat loss but not much (10% through the floor) so, depending on the price, the payback period could be decades, the wall/roof will be more cost effective.
Can't you do the floor from under in the garage? Continuous 100mm celotex (not bits between the joists) held up by some more plasterboard to maintain any existing fire protection.

 

[securespark]

Thanks for your help, fellas. Much appreciated!

23vc - we are having a cold flat roof stripped down and redone as a warm roof with 100mm ridged Kingspan.

cdbe - OK, thanks. I am not so much worried about the payback period, more by how many degrees it will warm the room. I'm trying to reduce cold and draughts to a minimum.

Unfortunately, underneath is not an option: there are myriad cables and pipes criss-crossing the underside of the ceiling. To insulate below them would mean dropping the ceiling to below the height of the door casing.

 

[securespark]

Just trying to price up the flooring and the underfloor insulation.
I guess any Celotex- type insulation would do?

 

[cdbe]

If you're not worried about payback/costs, in terms of insulating the floor and what sounds like huge disruption why not just check the draft proofing and put in a bigger radiator. With nothing to stop heat loss through the joists the celotex between will have limited effect.

Insulation doesn't make the room warmer, it just reduces the heat loss.

I have extensively insulated my house, it's no warmer than it was before - I just have slightly smaller radiators and slightly smaller gas bills.

I'd be amazed if insulating the floor as you propose would save you more than £20 a year.

 

[phatboy]

If you're not worried about payback/costs, in terms of insulating the floor and what sounds like huge disruption why not just check the draft proofing and put in a bigger radiator. With nothing to stop heat loss through the joists the celotex between will have limited effect.

Insulation doesn't make the room warmer, it just reduces the heat loss.

I have extensively insulated my house, it's no warmer than it was before - I just have slightly smaller radiators and slightly smaller gas bills.

I'd be amazed if insulating the floor as you propose would save you more than £20 a year.

My experience is quite different, although hard to tell which insulation did what.

We have a solid walled, suspended floor bungalow. 90mm EPS external insulation was installed, and 50mm Celotex between the joists. In the winter of 2015 before we started, we had nights where we couldnt get the house above 14 degrees. After the work, we had no issue maintaining 21 degrees, and the heating bill almost halved. Last year I topped up the loft from 100mm rockwool to 300mm, cannot tell if it made a difference.

 

[cdbe]

Do the (not very scientific) maths. Heat loss through floors is reckoned to be 15%.
If your gas bill was £600 and halved to £300 and you have 6 rooms you've saved £50/room per year - 15% through the floor = £7.50.

If you couldn't get the room up to temperature before then your heating system was undersized.

Don't get me wrong, I'm not anti-insulation, having put loads in my house, but it's difficult to make a saving on retrospective floor insulation even if you do it yourself on the cheap.

 

[securespark]

Thanks, everyone, I really appreciate your input.

We are doing the insulation partly to prevent heat loss, but also for draught-proofing purposes.

When the wind blows, we get some awful draughts under the skirting.

So we need to do something to stop this, if not full-blown under-floor insulation. I do get very cold, particularly hands and feet. Poor circulation and all that....

 

[securespark]

Have just clarified prices with him, as I was unsure if the refitting of the en-suite was included. It isn't.

So, the room size is 5.7m x 3.1m.

His estimate is for:

Taking down a remaining wall of the en-suite (1.7m long, half of which is a doorway).

Taking up existing chipboard floor and skirting.

Fitting 100mm Celotex under floor, then fitting new 22mm green chip floor & pencil skirting.

Re-build ensuite walls 1.7 x 1.6m including dry-lining, but not including the cost of waterproof board in the shower.

Dry line ceiling and fit polyurethane coving in bedroom only.

Skim ceiling and walls.

Provide large skip for waste.

£9200.

Are we being unreasonable in thinking that is over the odds?

 

[23vc]

Sounds very high to me.