Self levelling concrete in France.

[olddormouse]

Hi there, I'm new to all this but there seems to be a world of wisdom out there so here goes.

We've (foolishly perhaps) decided to convert an attached barn into living accomodation. It measures approximately 10 metres square and has an earth floor as many houses do here in central France. I've taken levels (thanks to a friend) and the floor drops approximately 12" from front to back and there are underlying rocky bits.

I've heard somewhere that self levelling concrete poured from a tanker is widely used here and wonder
a) is that the way to go ?
b) Would I need a DPM under it all, on top of the earht floor
c) I have masses of old roof tiles, should I break them up as ballast and if so to what height below the level for the pour.
d) I'll need to lay in pipe and wiring routes.....above or below the rubble and how far beneath the self levelling please ?

I'm keen to try and get a floor laid before the winter so that I can work on it putting up walls etc until the Spring but am a little overhwelmed the more I look at it so any advice welcome.

Bill (Olddormouse.)

 

[mointainwalker]

Bill

It's been a few weeks, so have you got the info you want ?

 

[olddormouse]

Hiya,

No, not really but nothing stands still. I'm just back from France and have got a bit more knowledge than when I posted the first thread. I'd still welcome some guidance on what's best for insulation / protection for electric / water runs under the cncrete if possible.

Thanks. Bill

 

[cmother1]

I don't think anyone will be able to give you authoritative advice unless they've a good working knowledge of French building regs. (Are there any? Are they national or local?). 'Les regs francaises' should give you chapter and verse on DPMs, slab depth, footings for internal walls & so on. The French have a strongly anarchistic streak, but I'd have thought some form of building control existed.
(If you want to see real anarchy in the raw check out Italian electrical wiring!)

 

[mointainwalker]

Bill

You've got to be a lot more precise with your questions.

e.g. "What's best for insulation ? "

Well, polyurethane (PU) has the best U-value but costs about E 25/m2 for 100 mm and is rigid and strong enough to walk on, fibreglass costs 5 times less but compresses and cannot be used in all situations, so the right answer depends on the question.


"Protection for electric ? " What ? Fuses, MCB,s , against lightning-strikes , for wires in walls, against vermin ? Sorry, my crystal-ball is a bit hazy tonight.


I'm a self-builder here and whilst there are regulations, they apparently do not apply to private individuals. Good, eh ? And as far as the professionals are concerned, they have the obligation to stick to regs, but as far as I know there are no inspectors who ever do any site visits to check work.

UK professionals reading this might think I'm exaggerating, but when my architect submitted plans for a barn-conversion which included creating a floor 9.5 m x 6.3 m at second-floor level, the plans just showed lines, not stating if the material was wood, concrete or papier-mache and no calculations at all.

Looking at your first post.

I do not believe there is such a thing as self-levelling concrete for a floor-slab, although there is self-levelling screed.

A DPM(plastic-membrane ) should be put in, it won't cost much, think I paid about E 40 for 100m2

I don't think your tiles will be suitable for hard-core, but I am not a professional. You may possibly not need hard-core, it depends on your soil conditions.

My first bit of advice would be not to rush at the job without preparing yourself with some knowledge or someone who is knowledeable to help you.

This is because you need to think about a lot of things and many are not obvious when you're doing this for the first time.

If you think about your floor, I would suggest that you start at the top and work down to see what depth you need.

Is the current floor height (pick either high or low spot as a datum) what you want as a finished floor height or does it need to be higher/lower ?

Build-up of floor: generally the slab is going to be 100 mm thick concrete ( I live in the Alps and they generally re-inforce here ) but then comes the question of insulation and how many mm you want to pay for.

As I said above, PU in 100 mm costs about E 25 and is mainly used for roof-insulation.Expanded polystyrene is about E 6 for 60 mm per m2. A 6.5 m3 load of delivered Ready-Mix costs E 1200 here - may be cheaper if you are closer to a depot - and you need at least 10 m3 . You can see that for 100 m2 you are already spending significant money, not including levelling the earth..

You need to know where -and at what level - the drains are that you want to connect to ( if there are any. If there aren't any, you need to find out about septic-tanks, size required and where you will site it ) .

I would advise you to buy a book or two on major DIY. These may enable you to do things yourself, but even if they don't, the articles will show how different bits of the house interact and need to be considered together. I don't know of any books dealing with renovations, but I bought a Collins DIY manual for about 20 pnds and also The HouseBuilders Bible. The latter deals with modern houses but I found it useful for new ideas that I might want to incorporate in my project.

The most useful advice has always come from people who have already done the same kind of thing locally.