Roof insulation

[Norman Verona]

I've googled "roof insulation ratings" and only come up with companies flogging insulation. Needless to say, they all claim there's is the best.

So, I have a barn with a thin slate roof and no felt or insulation. The inside will be plasterboarded with 10mm boards. The insulation will go between the p/b's and the underside of the tiles. I would prefer something not too thick as I want to leave the "A" frame exposed. What I need to know is:

a) what is the best way to insulate the roof regardless of cost

b) what is the most cost effective - eg; 95% for 50% cost

c) is there a Euro insulation rating code that I can use to get what I need in France

Oh, and of course will Tracy marry Justin... oops, sorry wrong thread  

Thanks.

ps, will probably have many more building questions as I progress with this project which will commence as soon as one of the buildings is sold.

edited cause I can't type/spell

[MVS]

I would suggest you have a look at the thin foil insulations such as Tri iso super 9 or 10 (which is the current UK building regs spec) or other competitors such as Thinsulex.

Pics & info

Thin foil info also som info on Wool insulation

Tri iso is manufactured in France as I recall by a company called Actis. both are about 15-20mm thick  and are stapled up. Obviously you will need to cut it to fit. This can be done with a stanley knife and easiest if you put it on a plank and use a stiff straight edge to compress the blanket. then seal the edges with foil tape.

This can be a bit of a fag time wise but otherwise you are left with cutting Kingspan / Celotex to fit which is a lot thicker for the same benefit. Or Stuffing a treated wool product or fibreglass/rockwool product in there.

Hope that helps a bit?!

Mike

[Norman Verona]

Mike, that's great.When we were building the gites I had a lot of isulating boards left over by RiF (previous owner). When we ran out I was advised by the local builders merchant (Gedimat, a large and expensive "palace") to use a silver foiled "blanket" I seem to remember it was 30€ per sq metre. However I see on the site you've linked it's £8.95 psm (£179 for 20sm).

I'll have a google for it in France

Many thanks

[Martin Keene]

£179 is a good price for a roll. We used to pay £175 trade.

ETA: We were using it for exactly the same reason, insulating vaulted ceilings. Apparently it only works properly if you tape *ALL* the joins. Well at least that's what building control said...

[Mark Stanton]

Jablite or Celotex are 2 trade names used in U.K they are available throughout europe - as previous thread for your use and application I would recommend use of foil backed insulation      

This will help in winter by keeping heat in and also in the long hot summers it will also keep your roof space a bit cooler      

[Norman Verona]

Mark, probably more important as we will have no "roof space" the building will be fully open to the top (or almost)

I've just read the manufacturers blurb on the French site and it's given me an idea. Instead of struggling with 10mmm plasterboards their install book shows the use of polystyrene boards. I'd be happy to staple poly boards and then paint them. Got to be easier than lisfting heavy plasterboards!

This is the barn to be converted The gites are too the left of the 2 garage doors and our house will be to the right. The offshot on the end (4.5m x 8m) will be the kitchen/breakfast room. The rest will be open plan with the bedrommabout 1/3 of the upstairs and a balcony along one side. The upstairs will have a balustarde not walls.

[Mark Stanton]

HHHMMMMMM poly boards     never been too impressed with them.

You can also get foil-backed rockwool insulation.

Yep, your barn conversion looks very similar to my place and with bedrooms being in "loft" space without foil backed system it can get very hot in summer      

I'm over there for a couple of weeks next weekend - if you're around I can try and drop by and have a look at things for you  

[Norman Verona]

Mark, If you look at the calendar on the web site ( www.frenchblat.com ) and pick a day that has a gite empty why not come over, we'll go out for a meal and you can stay the night.

Email me on norman@frenchblat.com

Thanks

ps, I was only thinking of the polyboards for the very high part, the bedroom can have plaster boards as it will be a lot easire to lift.

ed to ad that the calender is a link of the availability page. We have 2 suites so if 2 shown booked we're full.

[MVS]

£179 is a good price for a roll. We used to pay £175 trade.

ETA: We were using it for exactly the same reason, insulating vaulted ceilings. Apparently it only works properly if you tape *ALL* the joins. Well at least that's what building control said...

That is correct you need to foil tape all cut edges and joints when attached to create an 'air-tight seal' or else the stuff will not achieve the insulative values they quote.

[Mark Stanton]

PM to Norman  

[Norman Verona]

answered

[jedi]

be carefull with triso super 10   as its slowly being rejected by a lot of building control offices   i dont know about in france      how deep are the rafters  could you use cellotex/kingspan   about 100mm     you need to take airflow into consideration about 50mm

[Norman Verona]

Jedi, You're getting too technical for me.  

It's a French Hanger (barn). It has huge oak "A" frames, then lats onto which is "clipped" slate tiles. There is nothing underneath at the moment. The bit that we're conevrting is 12m, the whole barn is more then double that. (see picture).

My (rough) calcs are. Each pitch is (aprox) 7 meters (the barn is 8m wide and the length is 12m). So 12 x 14 x 11.90€ per meter for Lafarge reflective sandwich (14 layers) leaves 1.80€ change from 2000€. Then add on 8x 4.5 for the offshot which will be another 500€. So I get the roof insulated instead of the huge TV HM wanted. Seems a fair deal to me.

Thanks for teh advice.

Ps the French building inspectors (if they exist) won't be involved as it's an existing building for which we have planning consent for gites. The conversion is just like the gites - but different  

ed to ask, any idea why it's being rejected?

[MVS]

QUOTE

ed to ask, any idea why it's being rejected?

If it's anything like what they did with Tri iso 9 a few years ago, it is because they (Actis) would not put it through UK 'Hot Box testing' as it works in a slightly different way to how they test in the UK. However it is all E marked for use in EU but we in the UK work things out /test differently (if I understand things correctly, open to correction )

Also there are UK manufactured equivalents ( I mentioned Thinsulex) which have, and meet UK specs for all Bdng regs depts, but they (Thinsulex) stipulate 120mm of rockwool/fibreglass in addition to meet the current U values for a room in a roof space.

[Norman Verona]

Em, not sure it matters in our case, we dont have a "room" in the roof space - it's totally open plan. There is a "landing" which will be a bedroom. The bathroom is enclose by a wall but probably won't have a seperate ceiling. There will also be a gallery along one side, other than that it floor to roof.

Thanks.