The cost of home insulation in France

[cassie]

I hope to get a Permis soon to convert an outbuilding in Brittany into habitation.

It seems that mineral wool is the major/only type of insulation that is proposed by builders/architects

Nobody seems to have heard of P. I. R. ( poly-iso-cyanurate)... trade name Celotex....which has approx half of the conductivity of mineral wool.

This means it gives the same degree of insulation for half the thickness.....leading to significantly increased internal volume.

If it possible to buy in France how much does it cost?

(It is possible to buy seconds of Celotex in U.K.at a supposedly low price)

Also, what is the typical cost of mineral wool in France? and where is the cheapest place to buy it for a non-resident?

In the U.K. there are always special offers....not long ago Wickes were doing a "Buy one Get THREE free" deal!!.....But it is a bit bulky to transport!!

Any advice would be welcome.

[Chancer]

It is often cheap in the UK brico sheds because it is subsidised by the energy companies against their carbon taxes.

The Knauf ecose insulation that I have bought from B&Q from between £1.66 and £5.00 per roll (5.44m2) costs €47 from a grossiste here fo a roll of only 5m2, does that answer your question about the chepaest place to buy for a non resident? [;-)]

The closest that you will find to cellotex that is available everywhere is extruded polystyrene but sit down when you work out the cost.

[mint]

The chap (French) who installed our woodburners used celotex for lining the chimneys, etc.  I saw the name so it must be the real McCoy.

His fees ran into thousands so perhaps the celotex might be lightweight but I think the artisan thought that weight was worth itself in gold.

[BIG MAC]

Maybe worth filling a lorry with the stuff?

[Devon]

My place consumed about 220 sheets. The best price I could get for the French equivalent was about £60 a (2.5m x 1.2m) sheet. I sourced celotex at £17 a sheet in the UK. The exchange rate makes expensive French insulation even more costly. I would hire a van and buy in the UK if you need a large amount.

[Théière]

The French equivalent.

http://www.recticel.fr/

 

[lh]

I did the same search last summer and we ended up buying in the uk (Kingspan but its the same as Celotex) and transporting out with a big trailer - 3 trips and it was still cheaper that way!

[Théière]

Celotex will deliver to France if the order is large enough they informed me. Kingspan not interested.

[ericd]

Am considering going shopping for insulation in Poland (Rockwool or Celotex equivalent) and trucking it back to the house. I will be going there end of May for business and will spend some time in the DIY shops. Will report back then.

[mint]

When the rockwool or glass fibre sheets are on promo, they are not too bad (sorry, can't remember the exact price).

For us, the expense was having all the roof tiles lifted, the insulation sheets slipped in between the purlins and then the tiles replaced.  It was either that so that at least the inside of the house wasn't disturbed or insulation sheets applied to the upstairs celing which would have utterly destroyed the look of the beams.

[Théière]

Very true Sweet, I am down to do ours either the end of this season or before the next and I will put insulation under the purlins but still enough to keep the majority of the beems showing.

There is no insulation at the moment and that's not great.

[mint]

Teapot, the insulation made a tremendous difference last winter.

If you bought the insulation in sheets, the ones with the paper backing on one side, it's not difficult to lift out the tiles from outside and push the insulation up to the ridge.  That way, you shouldn't have to take off the ridge tiles.

If you have the same sort of roof tiles as we have (the ones with the overlapping profile), you can just lift them off as they are only held in place by their own weight.  Then, once you get the insulation down, you just replace the tiles.

Whilst you're at it, push some of the insulation down a few feet into the wall cavities, if you have cavity walls and stop some of the draught.

It was a tedious rather than a difficult job.  It's just that OH is too elderly to be climbing up on roofs and I am too weak to lift all the tiles so the labour component of the job was the most expensive part.

The inside is, of course, totally untouched and all your beams, etc should not be affected at all.

[Théière]

In our case Sweet, because there is no insulation there is actually nothing to stop the back of the placo absorbing water therefor sagging. The air flow dries it so its not damp. People think it's "charm" "rutique" It's a bad job we inherited and I know it so rip out the inside and re-board, oh joy [:)]

[mint]

Ouch, expensive, messy and not an enjoyable job, Teapot!

But, oh the pride and joy when it's all done.....

Don't think of the process, just concentrate on the result!  Get the camera out, take before and after, and post the pictures on here so that we know you aren't slacking on the job.....[:P]

[Chancer]

I had been pondering today whether the pare vapeur (paper backing) on French insulation is necessary or does anything at all, clearly not for above ceilings and internal cloisons but I was wondering if it did play a role where single skin external walls are lined with metal stud and placo.

Your application Sweet seems even more of a defi for the placo, I guess it is working and we can see that teapots uninsulated placo goes through damp and dry cycles but if it had laine de verre without pare vapeur would it be better or une catastrophe?

I have a vested interest as I have gradually been bringing over loads of Knauf insulation whenever B&Q have had it subsidised (thankyou British Gas) and as soon as I have got the studwok up will be using it against a solid double brick outside wall, I have used up all my remaining French stuff with pare vapeur.

I have just returned from delivering 22 rolls of it to a French self builder, he and his mate want a load more and also  bought all 3 of the Makita drills that I was also flogging, we were chatting about the implications of using it against single skin rendered parpaing walls.

If the insulation is in contact with both the outside wall and the placo (which it will be in my case) is the warm inside going to draw in humidity from the cold damp outside? I think yes, but would a pare vapeur prevent this from reaching the placo or would it just evaporate anyway.

Lots of questions but i would ike to know if you or anyone else has experience of this, opinions also welcomed of course [:)]

[ericd]

There are various videos on YouTube showing the various steps of "combles amenageables" loft insulation. Once the Rockwoll/brown paper slices have been fitted between the rafters, they actually put down a heavy gauge plastic sheeting that is carefully sliconed to all sides in order to stop drafts coming into the room (this is called air barrier). Only after these plastic sheets have been fitted, do they start screwing the plaster boards down.

[Théière]

Yes there should IMO be an air gap, the rock wool/laine de vere insulation should not make contact with both surfaces. The plastic sheet could also cause water to condense and in the case of rock wool or glass once damp the insulation properties fall off very quickly. A proper air permeable barrier should be used.

Lots of info from  DuPont

 

 

[mint]

If you've got that thin tin foil stuff above the plasterboard, that should be OK to stop the ingress of damp.

Then, because you have the purlins resting on the rafters, there is already an air gap.  Then, unless you have slates as a roof covering (they fit pretty tightly on top of each other) there is more circulation when you put the usual canal tiles on top of the insulation material.

Because of the profile of the tiles (with the "rounded canal"), there is plenty of air circulating under the tiles anyway.

However, if you do board up the roof above the insulation layer, then admitttedly you should introduce some vents for circulation.

Depends how much work and money you wish to commit.  IMHO, some of the so-called regulations over-provide and a lot of it is "sledge-hammer-to crack-a-nut".

[Chancer]

Its too late to reconsider my roof/grenier as it is already boarded out, my rafters rest on the purlins though. I dont have much of an air gap as I interposed extruded polystyrene between the isolant mince and the tiles (tuiles losangées, like tuiles Marseilles) and there is only 8cm rafter depth (chevrons).

I am more concerned with using laine de verre without pare vapeur on solid brick walls as I am doing at this exact moment, I agree with the theory but in practice surely the most common practice of dot n dab with doublage is far worse regarding humidity?

I had one wall where the doublage was black with mould from top to bottom, it just fell away from the wall allowing millions of individual billes of polystyrene to wash across the floor, I repaced it with rails, laine de verre and BA13 and have no firther problems but I did use a pare vapeur and placo hydrofuge, that said nothing shows up on my damp meter.

Do you think that using standard placo and laine de verre sand pare vapeur can be any worse than doublage?

[cassie]

What is "doublage"?

[cooperlola]

[quote user="cassie"]What is "doublage"?[/quote]Thanks, Cassie, because I always thought it meant dubbing.  Shows what I know.[8-)]

[Chancer]

Sorry girls!

Doublage is placo (oops, plasterboard) with polystyrene insulation stuck to the back of it, I dont know of it in the UK hence the use of its French name.

I think the stuff is a total bodge hence its popularity in new build pavilions, it also only has 10m thickness of plasterboard as I found to my cost when after putting up a line of kitchen cupboards for my ex, she never said anything about putting stuff in them [6]