Insulated Plaster Boards?

[HardTarget]

Looking to dot and dab the walls in my semi and wish to use 25mm insulation + 12.5mm plasterboard something like CELOTEX for the ouside walls. Would these be the correct boards as I am not sure what the version or type of CELOTEX I need?

 

[ban-all-sheds]

Looking to dot and dab the walls in my semi and wish to use 25mm insulation + 12.5mm plasterboard

Why?

 

[HardTarget]

Had a couple of plasteres look at the walls and give us a price on skimming them, only to be told I had to remove all the plaster as it was shot and that I should dot and dab the walls and if I do then to insulate any ouside walls with at least 25mm while I'm at it as it. Sounded like good advice?

 

[ban-all-sheds]

Sounded like good advice?

Well......

Have you got solid walls, or cavity?

25mm might be insufficient - have you done the calculations for the new U-value, and compared it to the guidelines in Approved Document L? This work is notifiable, remember, so you need Building Regulations approval.

If the interior wall surface will be noticeably colder than the room you'll need a vapour control layer, which creates difficulties where you have sockets and switches etc, or pipes passing through.

If you move the sockets & switches forward, will the cables be long enough?

Fixing things to the walls becomes a pain. Do you have CH radiators hung on the walls? Cupboards? Shelves?

It's not just the walls of course, you've got all the door & window reveals to do - do you have enough clearance around all the frames?

 

[HardTarget]

Sounded like good advice?

Well......

Have you got solid walls, or cavity?

25mm might be insufficient - have you done the calculations for the new U-value, and compared it to the guidelines in Approved Document L? This work is notifiable, remember, so you need Building Regulations approval.

If the interior wall surface will be noticeably colder than the room you'll need a vapour control layer, which creates difficulties where you have sockets and switches etc, or pipes passing through.

If you move the sockets & switches forward, will the cables be long enough?

Fixing things to the walls becomes a pain. Do you have CH radiators hung on the walls? Cupboards? Shelves?

It's not just the walls of course, you've got all the door & window reveals to do - do you have enough clearance around all the frames?

Thanks for the reply, the walls are cavity, as for the work being notifiable I am not sure as I am doing the work myself? The only reason I was going with insulated plaster board was on part down to the plasteres who advisede me to do so as it was worth it seeing as I have to take the plaster back to brick. I have stripped all the walls and left the ceiling as they were good. Also the house is being rewired so I should be fine for the extra cable length. The windows and doors will be a problem, also I will have CH fitted too, but I will have to find a solution to each problem as I go. :/

 

[ban-all-sheds]

Thanks for the reply, the walls are cavity,

Considered CWI?

as for the work being notifiable I am not sure as I am doing the work myself?

Makes no difference.

I will have to find a solution to each problem as I go. :/

Or don't put insulation on the walls.