Cold room with inadequately insulated floor?

Hi all,
A friend of mine has a flat built around 1990 I guess. It was built with electrical ceiling heating (don't ask me what they were thinking of). He's had gas central heating put in and ditched the ceiling heating. The problem he has is that his living room is always too cold in the winter. It's quite a large room, and at a quick glance I would guess that the rad is inadequate for the heat loss. He could just upgrade the rad. But the real problem seems to me that the concrete floor of this room is probably not properly insulated. He complains that the floor always seems cold in winter.
The room is on the first floor, but underneath it is just an outdoor space used for car parking which is completely open to the elements. I don't know what insulation they put in when they built it, but I reckon some celotex screwed to the underside (ie the "ceiling" of the parking area) would be a help. Any thoughts on this? What should he screw over the celotex - there's no chance of rain hitting it directly, so would normal plaster board do, or is there some sort of exterior version?
Cheers!
Martin
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Anything would help. Even some garage doors to reduce air movement. Or keep some livestock down there - that's the really traditional solution.
Celotex have lot of info on their website about using the products externally (http://www.celotex.co.uk/Applications ). Possibly cover it with studwork and a suitably graded plasterboard or cement board (http://www.knaufdrywall.co.uk/home/index.html ).
This would count as "building work" though and require paperwork.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
RubberBiker wrote:

Surely not, if you're just adding to what's already there, as opposed to ripping out the old and re-installing. If that were the case, you'd need building regs permission for laying rolls of glass-fibre insulation in the roofspace...
David
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, really. It's "substantially upgrading a thermal element". Loft insulation is exempted as it's "not enclosed within a building element".
See http://www.communities.gov.uk/publications/planningandbuilding/buildingregulationsexplanatory (mentions cavity wall insulation on page 25 as requiring building regs compliance).
I mention it as the proposed work is external, so the possibility of getting caught out is greater.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Martin Pentreath wrote:

I'd have thought adding celotex-type material below sounds a good idea.
You can get various types intended for exterior use like this one which comes bonded to 6mm ply: http://www.insulateonline.com/index1.htm?products.htm~main
I don't think plasterboard-bonded stuff would be a good idea - even if not exposed to water directly, it's still a potentially damp environment for which plasterboard is not suitable.
David
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks to both for the quick replies. Lobster, the ply-bonded stuff sounds good but the Kingspan link just takes me to their "products" homepage, I'm guessing you mean the stuff with code Kingspan Thermaroof TR31 zero ODP. Their website doesn't let you link directly.
Presumably for the application I'm talking about there aren't any vapour control issues? I would suggest just screwing it to the underside of the current parking area ceiling. A nice easy job, he's a DIY novice.
(Livestock a nice idea, but a flock of sheep is not really a possibility down Sarf London, they would be killed by herds of marauding rottweillers).
Cheers!
Martin
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
martin snipped-for-privacy@hotmail.com wrote:

Sorry yes, that's indeed what I meant.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Martin Pentreath" wrote

Whatever is there already should at least have been satisfactory as a fire break/stop, bearing in mind it's above a garage. Whatever you do should not compromise this fire break obviously.
Phil
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Your friend is living in my old flat! Or one very much like it - Sutton, Sarf London, in case you're wondering.
Yes - the ceiling heating is the evil of evils and the floor, over a triple car port was freezing in winter. I think he'll find he has the following floor construction in all likelihood:
Carpet/whatever Flooring chipboard Jablite (EPS - not sure what thickness - probably 25-50mm) Beam and block concrete sub floor Howling gale. Random chavs drinking Tesco Value Lager His car bonnet.
The only two things I can think of against insulating under the floor are:
1) Technically it's not his - or possibly 1/2 or 1/3 is, wherever his car port is.
2) What to do about service lighting - go round it leaving a gap?
If he were doing a refurb, I would take the floor up inside, rip out the jablit and put in celotex, with an extra 25-50mm depending on what ceiling height he is willing to lose, then re-lay the floor.
If that's unfeasible, perhaps a chat with the management company to agree to insulate the underside in a way that everyone is happy with, dropping any service lighting if needed. The landlord's permission may be needed, but as they are almost certainly some crappy pensions company, they probably won;t care and will go along with whatever the management company agree with.
Cheers
Tim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.