Insuated plasterboard or Stud system with insulation?

kodak

Hi all,

Need advice here

Old 1 story extension that we are gutting, 5m long x 3m wide

Cavity Block construction with a low pitch roof (flat)

Its has no insulation on walls, just small battens with plasterboard and ceiling has no insulation.

So what the best system to use?

Considering;

Would like to keep it as wide as possible

Little or no roof space (400mm reducing to 100mm) approx

Will be replumbed and rewired

Costs..


All help is really appreciated


Could a mod correct the title?

embracingLife

You didn't explain clearly........."insulated plasterboard or stud system with insulation" are basically the same thing!

With the "stud system with insulation" what type of insulation is that? Is it foam/beads/fibreglass etc?!

First thing you should/must do is get insulation pumped into the cavity blocks as to do the insulation on inside will be half the job.

Once the cavity walls are pumped then either or the two above methods.
But you'll need to know where to put the pipes/cables if you will be running any along the walls.

The best system to use is the insulated plasterboard as the insulation is superior than other types of foam etc and its easy to cut out the foam with a hand saw to align where the cables/pipes will go.
You then attach these plasterboard sheets to the wall by drilling a hole through the plasterboard into the wall at several places all over the sheet and hammer home plastic bolts that fix the sheets to the wall. These plugs/bolts are availible at the hardware that sell the sheets-the bolts are used only for these sheets.
You'll need a plasterer to skim the sheets then.

Best way to find out price-phone nearest hardware and give them spec and ask for best price..........make sure you get the kingspan insulated plasterboard (which are yellow foam) as there are sh1tty types that are basically polystrene foam stuck to plasterboard.

Alternately you could do the job yourself and save money----are you a man?!

good luck

embracingLife

Just reread your post and you want the attic done too.

You can put insulation between the roof joists and nail plasterboard onto joists. Here you can increase the insulation slighty by using a type of ceiling plasterboards that have a layer of insulation on them-approx 1 inch.

I'm not 100% on the whole thickness you're going to put into attic but thats the general way it'd be done. I hope no insulation regs fanatic is going to pick over my post and give me the third degree !! :pac:

embracingLife

another point:


"Would like to keep it as wide as possible"

what do you mean?!

kodak

embracingLife wrote: »

You didn't explain clearly........."insulated plasterboard or stud system with insulation" are basically the same thing!

Insulated backed plasterboard, Studs with Rockwool or Similar

embracingLife wrote: »

First thing you should/must do is get insulation pumped into the cavity blocks as to do the insulation on inside will be half the job.

It's a cavity block, I dont think pumped insulation would penetrate every block, or would it? Also I'd be concerned with dampness passing through.

embracingLife wrote: »

Alternately you could do the job yourself and save money----are you a man?!

good luck

Will be do this element myself.


What i propose is,

50 x 100mm studs, filled with 100mm Rockwool

50 x 50mm horizontal studs, services will run in area, insulated with 50mm rockwool

Vapour control barrier

12.5mm standard Plasterboard with a skim finish.

I'm getting pretty good u-values on this.. Surface condensation is not a problem but it is coming out with interstitial condensation during the winter but will try out during the summer months...

kodak

embracingLife wrote: »

Just reread your post and you want the attic done too.

You can put insulation between the roof joists and nail plasterboard onto joists. Here you can increase the insulation slighty by using a type of ceiling plasterboards that have a layer of insulation on them-approx 1 inch.

I'm not 100% on the whole thickness you're going to put into attic but thats the general way it'd be done. I hope no insulation regs fanatic is going to pick over my post and give me the third degree !! :pac:

For the ceiling, I think i will use a koolterm k7 board between the joists and where possible i will use rockwool or fiberglass over this where possible and space allows.
Then an insulated backed plasterboard fixed into roof joists with a skim finish.

kodak

embracingLife wrote: »

another point:


"Would like to keep it as wide as possible"

what do you mean?!

The room is only 3 meters wide. The method i'm thinking of will reduce the room by around 360mm

Cheers for your help

embracingLife

kodak wrote: »

It's a cavity block, I dont think pumped insulation would penetrate every block, or would it? Also I'd be concerned with dampness passing through.

Will be do this element myself.


What i propose is,

50 x 100mm studs, filled with 100mm Rockwool

50 x 50mm horizontal studs, services will run in area, insulated with 50mm rockwool

Vapour control barrier

12.5mm standard Plasterboard with a skim finish.

I'm getting pretty good u-values on this.. Surface condensation is not a problem but it is coming out with interstitial condensation during the winter but will try out during the summer months...

I got my house pumped about 4 years ago by a company called www.shannoninsulations.com who use [FONT=Verdana,Arial,Times New I2]Sprayed Polyuretahne Foam
[/FONT][FONT=Verdana,Arial,Times New I2]which filled every nook and cranny! The foam does not deteriote over time and stays as a foam. NO DAMP either.
[/FONT]So much so that the foam came out under skirting boards/window ledges/door frames where there were cracks in the walls that I didn't know cracks were!! The house is unbelievably warmer and with new pvc windows I have the boiler at medium setting than what I used to have it at max setting.
Also the house heats up quicker,in about 20 mins after boiler turner on and when boiler goes off the house stays warmer for longer.

You can then if you want to fit plasterboards to walls, however I recommend you use the insulated plasterboard as they are SUPERIOR to the other method. I have used them several times over the years and would never use anything else. These boards come in thinckness from 10 to 50mm foam stuck to 12mm plasterboards nailed to walls.

But if you want to go the other way,suit yourself.

kodak

embracingLife wrote: »

I got my house pumped about 4 years ago by a company called www.shannoninsulations.com who use [FONT=Verdana,Arial,Times New I2]Sprayed Polyuretahne Foam[/FONT]
[FONT=Verdana,Arial,Times New I2]which filled every nook and cranny! The foam does not deteriote over time and stays as a foam. NO DAMP either.[/FONT]
So much so that the foam came out under skirting boards/window ledges/door frames where there were cracks in the walls that I didn't know cracks were!! The house is unbelievably warmer and with new pvc windows I have the boiler at medium setting than what I used to have it at max setting.
Also the house heats up quicker,in about 20 mins after boiler turner on and when boiler goes off the house stays warmer for longer.

You can then if you want to fit plasterboards to walls, however I recommend you use the insulated plasterboard as they are SUPERIOR to the other method. I have used them several times over the years and would never use anything else. These boards come in thinckness from 10 to 50mm foam stuck to 12mm plasterboards nailed to walls.

But if you want to go the other way,suit yourself.

I will investigate insulated plasterboard now. My first thought are an issue with services, I can't chase the cavity block so I'll have to batten it out. Haven't really explored it but i deffo will.

Here is a break down of my u-values

Guy:Incognito

Kodak, whats the program your using to do the room mock ups and the calculations?

kodak

Stekelly wrote: »

Kodak, whats the program your using to do the room mock ups and the calculations?

It's Build Desk U 3.4

http://www.builddesk.co.uk/our+software/builddesk+u/download

GreeBo

I used rigid kingspan within the batons and then plasterboard with 20mm kingspan bonded to it.
I found the rigid insulation far easier to work with than any of the fibre methods.

kodak

GreeBo wrote: »

I used rigid kingspan within the batons and then plasterboard with 20mm kingspan bonded to it.
I found the rigid insulation far easier to work with than any of the fibre methods.

That's a good method alright as the rockwool will probaly sag after a number of years. Although I can't do this as my services have to go somewhere. I cannot chase the wall. So I could use rigid for the first 100mm in the studs and then 50mm rockwool in horizontal service area, finished with a vapour control and plaster skim.

I know this would be better long term, will just have to price rigid -v- rockwool and see what the budget says!

Thanks for that

This is the results on the U-Value..

GreeBo

kodak wrote: »

That's a good method alright as the rockwool will probaly sag after a nmber of years. Alhough I can't do this as my services have to go somewhere. I cannot chase the wall. So I could use rigid for the first 100mm in the studs and then 50mm rockwool in horizontal service area, finished with a vapour control and plaster skim.

I know this would be better long term, will just have to price rigid -v- rockwool and see what the budget says!

Thanks for that

This is the results on the U-Value..

I just put conduit through the 50mm kingspan for services. You can also leave a gap between the kingspan and the boards, just get thinner kingspan or shim up your batons 20mm or so.

I also had vapour barrier on top of the 50mm kingspan, but the insulated slabs are all foil backed so its probably overkill.

How are you planning to fix the vapour barrier? I stapled to the batons and taped the staples but as it wasnt a total refit had issues sealing the VB to floor/ceiling (used mastic in the end)

kodak

GreeBo wrote: »

I just put conduit through the 50mm kingspan for services. You can also leave a gap between the kingspan and the boards, just get thinner kingspan or shim up your batons 20mm or so.

I also had vapour barrier on top of the 50mm kingspan, but the insulated slabs are all foil backed so its probably overkill.

How are you planning to fix the vapour barrier? I stapled to the batons and taped the staples but as it wasnt a total refit had issues sealing the VB to floor/ceiling (used mastic in the end)

Yeah i might just do that with the conduit and run with with rigid,vb, and standard boards. Will price it tomorrow..

I wasn't sure on the VB, I was thinking a silicon or mastic myself, Will it damage it?
I presume i'll just continue go up the walls, across the ceiling, and down the other wall. Might just have to staple it on the ceiling?

Might be putting in solid wood floors,will know tomorrow, so will i continue it down the floor too? Do a complete wrap of the room? Protection of it may prove difficult!

Thanks for the help