Hello! We are about to start looking for a suitable way to put a solid floor into our barn. At the moment it’s a compacted mud floor. The barn was previously used to stable horses but now we want to use it more as a car garage and workshop so need something more solid and less grubby. The walls are stone and lime mortar and so we’ve heard that a concrete floor isn’t the best solution.
Does anyone have experience of limecrete or a similar type of flooring material here in France. It appears to be breathable? I have also been advised to put down a plastic barrier before laying any type of flooring. Does this sound correct?
Any advice, gratefully received as usual!
Thanks very much
Jane
Thank you Marina, that’s good to know, we are looking into all the comparable prices and long term effects at the moment!
Jane
Thanks Robert, the barn isn’t very damp at all at the moment and we’d really like to keep it that way if possible. I’ll keep researching prices and suppliers!
Jane
Dear Suzanne,
Just a word of warning regarding lime hemp render. Make sure you do a test area first, my plaster John had a problem when he was doing my wall. It seems my stonewalls are made up of granite and limestone and this made the lime hemp dry quicker in some place, then others.
He nearly gave up and took the whole thing off and he is a lime expert. He persevered and got a great finish in the end and I am very pleased with the results.
Hope this photo is not too big?
Hi again Jane,
Yes, it is better to dress the membrane up the walls as well. It helps prevent the concrete drying out too quickly at the edges. You may well consider an expansion detail at the periphery too. Usually in the form of flexible polyurethane foam rolls. Sorry, I don't know what they are called here in france. I'm sure I have seen them though.
The question as to why Limecrete may have been suggested is difficult to answer without actually seeing the job. But if you have existing damp that may well have been one reason. I would suggest though, that the salts or efflorescence as it is known which is usually the only visible sign of damp is easily dealt with periodically with a stiff brush and a hoover. I have seen it where the floor is earth and you cannot get much more breathable than that. I personally do not believe it is possible to stop damp completely in stone buildings. The answer lies in letting it breath and keeping it visible?? I may get some people questioning that particular statement though....we'll see ;o)
I went to demonstration regarding limecrete or rather lime hemp render very recently and the jury is still out as to it's merits as far as I'm concerned. I'll probably be shot down in flames for that as well ;o))
Hi, Jane,
I have just started to write a post for my blog regarding Limecrete, then I see your question on SFN.
I have laid a limecrete floor in my little cottage. It was easy to do and very strong, I have a sample block we did before we started, it's been sitting outside in Burgundy weather for the last two.years It's not cracked or weathered unlike the concrete I poured for the gate entrance.
I have never had any damp problems and I would recommend using it. It is more expensive than a concrete slab,but repairing damp walls all the time is also expensive.
Marina
Thanks Suzanne, we certainly don’t intend to do the floor ourselves as I said earlier, it’s just too big!
Good luck with yours, sounds like an interesting project.
Cheers
Jane
I don't think you could easily do the floor by hand Jane - our floor is 82m2 and we are using 2 concrete lorries (toupies) We're putting down 20cm of tout venant gravel and a DPM then the concrete layer. Our house is an old stone house too. Difference is ours will be habitable living space. We're putting in underfloor heating so there will be extra insulation and we're using a lime hemp render on the walls. I am still a little concerned if humidity will rise up from the foundations (which do have humidity) but I am hoping the ventilation system and lime hemp wall insulation will help with the thermal correction and regulation...if not...hmmmm.
As Robert said a Limecrete floor would normally be poured on a breathable membrane not a plastic one.
We chose concrete because the structural engineer has specified all the plans and as he's an engineer de beton...so beton is what we've got. I've pushed back hard on many other things to get the most eco and energy efficient solution but on this one I gave up.
Thank you Peter, luckily, the barn already has an electricity supply and my husband is putting in the water supply and drainage pipes so I’ll remind him to do those before the floor goes in!
Cheers
Jane
Thank you for this Robert, that’s really useful information. I wonder why we were given advice not to put a concrete floor down? Even though we’ve done all the restoration work to the house ourselves, we don’t intend to do the floor of the barn on our own. It’s just too big at 80sqm!
Would you recommended that the damp proof membrane goes a little way up the walls too?
Cheers
Jane
Hi Jane
I agree with everything that Robert has said but would add that you should think very carefully about putting in any extra UNDERFLOOR electricity cables, water supply and etc. I use my old barn as a workshop for all the furniture that I build and having extra power points was an absolute necessity, Ditto with a water supply.
If you are going to add a power supply, then my approach was to have an Electrician install a new sub-fuse board with a set of junction boxes, "boites derivation", for my power tools and lighting so that I was doubly protected against any overloads. Also, adding sockets and light switches is then easy as each circuit can be isolated whilst you do the work.
Peter
Hi Jane,
It's called Limecrete and in your case I would suggest it would be an unnecessary additional expense. Particularly if you then used a damp proof membrane which would defeat the object of the exercise.
Just an ordinary concrete floor, ordered as a floor (sol) should suffice. You would need to use a DPM (damp proof membrane) but that is as much about not allowing the concrete to dry out too quickly as to providing a dry floor. Even a concrete pad in the garden would be best placed using DPM...The reason you would need to specify to the supplier what the concrete is to be used for is because concrete for a foundation for example doesn't need to be as strong. You will also need to put in a welded mesh if it less than 6 inches thick. For a garage/workshop I would suggest 4 inches is plenty good enough. Depends on the size or area of course. If it is very long for example, you may need to have an expansion detail somewhere, usually in the middle ;o) You can buy these quite cheaply at brico depot amongst others obviously...sounds like the BBC...
Bon courage...