Limecrete floors

[freddie328]

In the Spring we will be starting a restoration of our 18th century timber framed cottage. As part of the work I'm considering taking up the existing concrete floors and replacing them with insulated Limecrete.
Has anyone got experience of living with Lime floors and what sort of coverings do you use?
The existing floors are not damp but there is damp in the walls where there are bricks and fire places, which Im hoping will be relieved by using a breathable floor, or is this likely to make no difference?
Thanks for any help in advance

 

[bennoa1]

Going to do the same but not got round to the floors yet as still doing walls and decoration upstairs. We had similar where the concrete under the carpet is OK but walls wet so the water is taking the easiest route up, ie the wall. Took the plaster of most rooms at lower level so drying out. We pan on using 9" square quarries on the limecrete - got about 400 now but need some more. We think there is a brick floor in our central room (the oldest part of the house) but covered in concrete. Hoping we can return this to brick but again on a limecrete base. Be interested to see how you get on with it.

 

[MatthewC]

I laid a limecrete floor in my kitchen in 2011 (was it really almost five years ago?); we covered it with (imported) black limestone flags. In areas of high usage (i.e. in front of the cooker) we have an expendable rug laid but otherwise it's bare. We clean it with a steam cleaner and water, or else with "Tile Doctor" cleaner with sponge and elbow grease.

This floor replaced a 6" clay tile floor laid pretty well directly on the ground and the whole floor was horribly wet (and had been for a long while). I also lowered the ground levels outside at the same time so I can't say which had the greater effect, but if doing it again I would still do both tasks. It works as advertised and the house is dry and warm - in fact the floor seems to be a bit warmer than a "normal" ceramic tiled floor with 4" of insulation underneath would be.

If you want the story of doing it, see my blog at http://houseintheenchantedforest.blogspot.com/ and filter by "limecrete". If doing it now I would use RFG instead of LECA (google "foam glass aggregate") but otherwise the advice in the blog still holds good. My materials came from Mike Wye in Devon, who also gave free advice as I had done one of their one day courses.

Matthew

 

[Flyfisher]

The thing about a breathable floor is that it is, er, breathable, which means that if it is laid directly on the ground (as most are) then water will permeate through it. If that water is not able to freely evaporate and disperse then it will inevitably accumulate.

Our oldest original floors (c.1550) were pamments or just bare earth. When the house was given a 'Georgian makeover' a few hundred years ago suspended floors were installed. Because of outside ground levels, air bricks were only installed in two of the three ground floor rooms and those rooms still have their suspended floors in good condition. The third room floor was lost through rot because it was laid directly on the pamment floor (with a carpet on top) and trapped the damp that rose through it.

The room is itself 'feels' dry enough and there is no musty smell or mould (probably because it amply ventilated through gaps around the windows!), but when we stacked some cardboard boxes on the floor one winter their bases were found to be very damp and musty, to the point of pretty much falling apart when lifted.

We have no intention of lifting the pamments but I have little doubt that if they were replaced with a limecrete floor then we would have the same basic issue. In other words, whatever coverings you choose they should permit adequate ventilation of the floor itself - and that includes furniture.

 

[88v8]

Edit your Profile to show your general location, then one might be able to recommend local(ish) suppliers etc.

Before we moved in here, one of the unscheduled jobs was to break out the concrete floor in the sitting room and replace with limecrete. The concrete incorporated a dpm, which no doubt worked fine but pushed the damp into the walls to the extent that the Gripperods had rotted.

The depth of the floor was dictated by the depth of the footing, or rather the absence thereof. So as to maintain the necessary 45 degree thrust slope, we were limited to 4" of LECA and 4" of limecrete.
Ideally the floor would have been 6" & 6". Even with the reduced thickness we were below the keystones, and if Building Control had been able to interfere, we might have had to underpin the walls. Fortunately the under-soil was firm and the floor has been crack-free so far (5 years).

There is no damp in the walls now, other than the external wall which remains and will remain partly below external ground level.

We used a builder experienced in limecrete. I would not let the job to Joe Bloggs. We found our builder by asking the limecrete suppliers - Ty Mawr in our case - for a list of their regular local customers. Our builder was not particularly local to us - 60 miles - but they did a good job on this and other tasks.

As to coverings, the floor was overlaid with stone slab and quarries, laid and pointed in NHL5. It is essential that no cement be used for bedding nor pointing otherwise the breathability will vanish.

Here and in another room where there are quarries pretty well on the earth, we have laid large Turkey rugs - wool, of course - on felt underlay. The felt is breathable.
No rubber, no artificial fibres.

Even thought the (1620) house is intrinsically 'damp' with a summer RH of c70%, there is no mustiness or deterioration in the carpets.

Felt underlay
http://www.carpet-underlay-shop.co.uk/wool-felt-carpet-underlay-12-c.asp?gclid=CKKSkc6_0LACFVMetAodYTJrXQ

Ivor

 

[88v8]

.....permit adequate ventilation of the floor itself - and that includes furniture.

Yes, we have noticed a strong tendency for our antique woodware to sprout mould. I hate the thought of external varnishing, but polish seems to keep it at bay. What is happening around the backs of immovable heavies, I prefer not to know.
Internally, unless cupboards are varnished, they become mouldy, likewise their contents.
I suppose by c17 standards, we have too much stuff.

Ivor

 

[Flyfisher]

I suppose by c17 standards, we have too much stuff.

Quite probably, and we definitely have different living standards, much of which can lead to a lot more internal humidity, all of which has to go somewhere.

It's all a matter of balance. So while we're busy restoring breathability to our properties and draught-proofing them to a level they've never before experienced, just give a little thought to adequate ventilation as well - which is something they probably enjoyed in the past.


(is this the time to bring up the 'rubber glove' analogy again? No? OK, I'll leave it for now)

 

[MatthewC]

What is happening around the backs of immovable heavies, I prefer not to know.

I don't want to know either. We have a purpose built L-shaped bookcase ("the library"), >6 ft high and about 9 ft total length, specially made for my wife's intellectual books. The chap who made it for us was surprised when I insisted on ventilation slots, and the back being 50mm from the (external) wall. It was only recently, four years on, that I realized that it cannot be moved from the room without major dismantling - but the floor there is suspended wood not solid.

In my post above I meant to say that the rug we have is natural woven and has no backing, so it is breathable.