TF Build; Any sense in fitting insulation backed pboard to some rooms & not others?

Folks,

Looking for some opinions. Informed sources recommend fitting insulation backed pboard to stud walls with insulation between studs also as one of the best methods for insulating a TF build. Budgetary constraints dictate however that I won't be in a position to fit the entire house with the insulation backed slabs. My question therefore is, is there any value in fitting these slabs to some rooms (for example the sunroom which has several window & door opes & a vaulted ceiling) & not others? I should also state that the sunroom opens into the kitchen/dining area & is open plan? Don't want to waste my money if the heat escapes through the walls in the kitchen/dining areas. Thanks in advance, apple1

Re: TF Build; Any sense in fitting insulation backed pboard to some rooms & not other

Yes it is sensible

Any extra insulation will make a difference to hte comfort level in your home. If you have to do it piece meal then so be it. Look at your vaulted ceiling also as you lose as much through the roof as the walls. No reason not to use same material on ceiling. Also look at sealing the plasterboard to your window frames before plastering. Special membrane & tape products available now for this. A lot of emphasis now on airtightness in homes and one of the major draught areas is around window and door frames.

Warning payback for this work may be long unless energy prices go totally haywire. However your comfort levels will increase and that's worth a lot - to me anyway!

Reg

Badge55

Re: TF Build; Any sense in fitting insulation backed pboard to some rooms & not other

Thanks badge, much appreciated. Is there any reference material I can refer to regarding the detailing for sealing between the slabs & window/door frames?

Re: TF Build; Any sense in fitting insulation backed pboard to some rooms & not other

if you are going to slab some rooms, make sure they are thermally broken from the other non-slabbed spaces... ie slab all the living spaces and not the bedrooms, then make sure your heating is zoned to take account of this.

have you contacted your TF manufacturer to see if they recommend slabbing with cpb??

Re: TF Build; Any sense in fitting insulation backed pboard to some rooms & not other

apple1 said:

Thanks badge, much appreciated. Is there any reference material I can refer to regarding the detailing for sealing between the slabs & window/door frames?

Click to expand...

Apple

Here is a link re airtightness products [broken link removed]

Note that these guys will all recommend a full airtightness membrane inside your house as well as blower door pressure testing etc. If you have budget constraints maybe this stuff is not for you.

This airtightness business makes sense and I believe it will be the way of the future but like everything else it is bl**dy expensive in Ireland. I like to think that if I started again on my house that I would do it but maybe the cost would change my mind. Note I am not an expert on this stuff - just an engineer with a healthy interest.

Tips for insulating

When using rockwool or fibreglass wool ensure that it is not compressed or squashed - works well only when loose / expanded to normal size

If you are insulating between the studs and then using insulated pboard try to ensure no gap between insulation and insulation backed pboard. There will be cold air in the cavity and if it is able to move freely between your layers of insulation then the outer layer is of very little value.

Reg

Re: TF Build; Any sense in fitting insulation backed pboard to some rooms & not other

Thanks Syd & badge.

Syd...regarding contacting the TF manufacturer, do you suspect that they might have an issue with using CPB to slab part(s) of the house? What issues might arise from using this? Just for info, each room in house is zoned individually with its own stat also. I will probably slab entire attic space, dwarf walls & ceiling with cpb (will try & squeeze the cents out of the budget!!)

Badge, regarding fitting the cpb tight to the rigid PU between studs, don't I need to leave a service cavity between the rigid boards & the slabs (either regular 12.5mm or the CPB's)? Maybe not, but would appreciate your thoughts.


Thanks again, apple1

Re: TF Build; Any sense in fitting insulation backed pboard to some rooms & not other

don't I need to leave a service cavity between the rigid boards & the slabs (either regular 12.5mm or the CPB's)?

Apple

i don't know what you mean exactly by service cavity but at the risk of repeating myself please note the following

If you have a gap between your PU and CPD that cold air from the cavity can move freely in then the PU is ineffective
reg

Badge55

Re: TF Build; Any sense in fitting insulation backed pboard to some rooms & not other

badge,

Yes, I understand what you're saying but by service cavity, I mean a gap to allow conduit, cable, socket boxes etc be ran & fitted behind the slabs. Perhaps I can "gouge" a channel or space in the insulation between studs to run/fit these? Thanks, apple1.

JM, having declared your interest in the company, can you post the name here? Thanks