Dormer bedrooms

gabbo is coming

Hi

I have two wooden frame dormer bedrooms built out of the roof, one structure. 12 ft x 24ft

Is it possible to externally insulate and put on a new roof on top of existing with insulation? Do you know who might be a good company to take on this work?


Attached is a view of it

chippy81

Hi

It's possible to do this work, you could take off existing pvc and put on 50mm insulation (xtratherm kingspan etc) and re clad in pvc or plaster or timber depending on what you like

I would strip roof and insulate between joists and use instated board again as above, ply wood and re felt roof. You could also use fibre glass or trocal roofing(more expensive but last longer)

Other option would be to put insulated plasterboard on inside and re skim but I imagine it's probably a small room so it would reduce it even more and if it's a bathroom them hassle of removing/ refitting ware and tiles

Can't recommend anyone specific as don't know what part of country your in but any good builder or roofer should have no problem with it.

BryanF

chippy81 wrote: »

Hi

It's possible to do this work, you could take off existing pvc and put on 50mm insulation (xtratherm kingspan etc) and re clad in pvc or plaster or timber depending on what you like

I would strip roof and insulate between joists and use instated board again as above, ply wood and re felt roof. You could also use fibre glass or trocal roofing(more expensive but last longer)

id suggest its best where timber is concerned to use a rain-screen cladding system outside such an insulation approach, to avoid Interstitial_condensation

chippy81

I was just outlining possible solutions to question asked, I didn't go into specifics of every job that could be done or list every step taken in the works.
If I was to do that I'd be typing all daylong and it would also make fairly boring reading

BryanF

chippy81 wrote: »

I was just outlining possible solutions to question asked, I didn't go into specifics

point taken

put on 50mm insulation (xtratherm kingspan etc) and re clad in pvc or plaster or timber depending on what you like

i was just pointing out that plaster, on kingspan, on timber frame backing is not the way to do things nor will an external insulation system cert show this detail.

chippy81

Fair enough, on hindsight what I should have said was depending on what finish you prefer and done correctly relevant to what finish you want. That might have made it cleaner without going into specifics. I do understand the differences in what would be used for those finishes. The question was can it be done, not how.

chippy81

Fair enough, on hindsight what I should have said was depending on what finish you prefer and done correctly relevant to what finish you want. That might have made it cleaner without going into specifics. I do understand the differences in what would be used for those finishes. The question was can it be done, not how.

gabbo is coming

chippy81 wrote: »

Fair enough, on hindsight what I should have said was depending on what finish you prefer and done correctly relevant to what finish you want. That might have made it cleaner without going into specifics. I do understand the differences in what would be used for those finishes. The question was can it be done, not how.

So what I'm picking up is make sure outer skin be impermeable so that the inner insulation does not get wet? Or am I stoking the fire here?

BryanF

gabbo is coming wrote: »

So what I'm picking up is make sure outer skin be impermeable so that the inner insulation does not get wet?

exactly, you've eloquently explained my point and what i was picking up chippy on

Or am I stoking the fire here?

no fire

id suggest you remove the internal plasterboard, install a vapour barrier/air-tight layer & new plasterboard, install insulation between the studs, then plywood racking board taped, installing a rigid insulation (better if breathable and combined as the racking board) outside the studs, followed by breathable felt, batten, cross batten and followed by your preferred finish, ensuring you vent the cavity. watch the window placement for insulation overlap

best of luck

chippy81

What about inside space with all that added. It is still possible to insulate externally while keeping it water tight. It would also save a lot of mess and re decoration of room or re doing it if it's a bathroom.

gabbo is coming

chippy81 wrote: »

What about inside space with all that added. It is still possible to insulate externally while keeping it water tight. It would also save a lot of mess and re decoration of room or re doing it if it's a bathroom.

Hi

Whole point is to not have to go near inside, otherwise I would take the hit and dry line.

Will only do the external if it is external only.

Talked to two builders, neither had a clue how to do it....

chippy81

That's the point I was making above, it saves on interior mess and re doing

Have you tried any roofer, perhaps the builders haven't dealt with it before and decided to shy away from it

gabbo is coming

There is a builder I know who is busy for the next two weeks, but he's the most capable builder I've come across, so will talk to him when he quietens down a bit...I'm more informed now of what I want....

BryanF

gabbo is coming wrote: »

HiWhole point is to not have to go near inside, otherwise I would take the hit and dry line.

in that case I'd suggest a breathable wood fibre board insulation (GUTEX or equal) outside of the timber stud works, followed by rain-screen cladding system with your preferred finish.

gabbo is coming

BryanF wrote: »

in that case I'd suggest a breathable wood fibre board insulation (GUTEX or equal) outside of the timber stud works, followed by rain-screen cladding system with your preferred finish.

Thanks

Excuse my ignorance but is the cladding not the finish? Is there a render put on the cladding?

BryanF

gabbo is coming wrote: »

is the cladding not the finish? Is there a render put on the cladding?

you'd like a render finish : in our climate, where there is a timber structure, its best to create a space for air to circulate outside of the insulation zone, this keeps things dry and is done similar to roof construction with 25x 25 crossed battens, then you have perhaps a cement fibre board which you can plaster & paint

chippy81

You should follow BryanF advice, having read some of his other posts on construction he obviously knows alot more than me (and everyone else it seems) is he Mike Holmes in disguise apart from actually being able to do any work only reading from a book and not having any real world knowledge

BryanF

chippy81 wrote: »

You should follow BryanF advice, having read some of his other posts on construction he obviously knows alot more than me (and everyone else it seems) is he Mike Holmes in disguise apart from actually being able to do any work only reading from a book and not having any real world knowledge

explain to me where you get this from ?

BryanF

@ chippy

I meet enough cowboys on site who's attitude is crap towards learning new ways to do things, reasons for not doing things &/or building regulations. & their easily spotted as their the ones who are unable to explain themselves without resorting to personal abuse. so do me favour and leave this type comment on your site, or couch!

chippy81

Building regulations!!!!! More ideas conceived in a office by people who have little or no real world experience. Also
posting comments doesn't make me a cowboy and before you say my attitude to building regulations does make me a cowboy its possible to do a good and proper job without making engineers and architects more money for over specing jobs

topcatcbr

chippy81 wrote: »

Building regulations!!!!! More ideas conceived in a office by people who have little or no real world experience

OMG

Building regulations normally come about because of known failure in existing building standards.

That said you do appear to have a good enough knowledge of insulating externally. The above attitude is worrying tho.

topcatcbr

BryanF wrote: »

in that case I'd suggest a breathable wood fibre board insulation (GUTEX or equal) outside of the timber stud works, followed by rain-screen cladding system with your preferred finish.

This is a good solution to the OPs requirements.

BryanF

are you apposed to

learning new ways to do things, reasons for not doing things &/or building regulations.

???????

chippy81 wrote: »

Building regulations!!!!! More ideas conceived in a office by people who have little or no real world experience.

yee Haw!!!!! and your happy to just accuse me of:

chippy81 wrote: »

not having any real world knowledge

when you haven't actual specified build-up? you prefer to to just intimate that my approach is to

over specing jobs

- now do us a both a favour, with 'your real world knowledge' and spec a solution, one that stands up to building regulations!!!!

Also posting comments doesn't make me a cowboy

imo by your attitude in this discussion, wild statements on Building regulations, and the need to have a go at architects and engineers validates my use of the word 'cowboy'

and before you say my attitude to building regulations does make me a cowboy its possible to do a good and proper job without making engineers and architects more money for over specing jobs

show me your specification? I'll be happy to discuss it rationally & without resorting to personal comments

chippy81

<snip>

Mod: Poster banned

topcatcbr

chippy81 wrote: »

<snip>

Never heard that saying. I'm in construction over 30 years. You appear to have little or no idea what engineers or architects actually do.

Instead of attacking other building professionals you might concentrate on providing solutions to the OPs question.

Penn

Chippy81 banned for suggesting there is no need to adhere to Building Regulations.

Back on topic please, folks. Thanks.