Breathable Floors

[MatthewC]

I'm sorry for raising this again - I've done a thorough search of the forum and Agony Uncle, and if anything I am even more confused.

In our proposed purchase (1830s stone built, Grade II, conservation area), the room across the back has mortared red and black Victorian tiles in a diagonal pattern, probably laid in screed direct on the ground. They do not look in fantastic condition as they have formerly been covered by something (lino? vinyl floor?) and in damp conditions the backing has attached itself to the tiles. Also, the floor is not level and there is a tile-less area where there was once a brick dividing wall for about eight feet. One other fundamental problem of the house is the ground outside which is higher than this floor by about 8 inches; I intend to lower the outside ground level as much as possible, being mindful of how deep the foundations might be (or not), but the ground generally is high-ish at the back of the house.

'Er indoors has just decided that we should use this room as the kitchen so the plan is to install a breathable new floor; it seems sensible to increase the height of the floor by about 6 inches (which gives a step up at the door), fit insulation and even possibly underfloor heating, with similar tiles re-instated.

I shall be engaging an architect and I've already spoken to a conservation officer but I'd like to know a few basics myself so that I can discuss sensibly with them. My initial plan for the floor was to use limecrete with LECA, but now I'm not so sure.

• Why do people imply that limecrete is very expensive? I can see it is not as cheap as concrete but it seems a price worth paying.
  Various specialists say that limecrete is warmer to the touch than concrete - is this true?
  If so, is underfloor heating really needed if the room has a wood burner?
  What are the relative merits of LECA versus Recycled Foamed Glass insulation?
  The Limecrete Company also do "Hemcrete". Has anyone used this and what are its merits (including cost) versus limecrete?
  What are the current/new building regulations regarding replacing a floor in a listed building?

NB Considering the poor state of the roof and the rising ground, the house is surprisingly dry, so I reckon that fixing the roof and the ground will fix the major damp issues.

 

[Moo]

They do not look in fantastic condition as they have formerly been covered by something (lino? vinyl floor?) and in damp conditions the backing has attached itself to the tiles. Also, the floor is not level and there is a tile-less area where there was once a brick dividing wall for about eight feet

Unless they're badly cracked, there's every chance that they'd clean up a treat and be re-usable**. Which would not only conserve a chunk of historic fabric, but save you the cost of buying replacements for the whole floor.
It's a pity about the eight foot gap, but would it be possible to lift the old tiles and use them in the middle of the floor, and put the new ones round the edges (where they'd be hidden under the kitchen units anyway)?


** One of the rites of passage for PPUK people is The Cleaning Of The Tiles. Most of us have done it and have memories of much sweat and tears, and are now the proud possessors of glorious gleaming floors.

 

[skier-hughes]

• Why do people imply that limecrete is very expensive? I can see it is not as cheap as concrete but it seems a price worth paying. It's more expensive yes, but very expensive is relative to one's pocket size and how scared a builder wants to make you
  Various specialists say that limecrete is warmer to the touch than concrete - is this true? I laid a part limecrete part concrete base for my greenhouse. I can't say I've noticed any difference in warmth, but I don't walk barefoot in my greenhouse everyday.
  If so, is underfloor heating really needed if the room has a wood burner? A choice you need to make, would underfloor be anywhere else, if not, it may be an expensive form of seldom used heating with cooking etc going on.
  What are the relative merits of LECA versus Recycled Foamed Glass insulation? no idea
  The Limecrete Company also do "Hemcrete". Has anyone used this and what are its merits (including cost) versus limecrete? Hemcrete I believe has additional hemp fibres in it which add to the insulating effect slightly and help hold it together.
  What are the current/new building regulations regarding replacing a floor in a listed building? no idea

NB Considering the poor state of the roof and the rising ground, the house is surprisingly dry, so I reckon that fixing the roof and the ground will fix the major damp issues. hopefully

 

[Penners]

Why do people imply that limecrete is very expensive? I can see it is not as cheap as concrete but it seems a price worth paying.

I'm sure it's a price worth paying. But that doesn't necessarily mean that everyone can afford it - hence the occasional implication that it's expensive. I'm sure a Jaguar is excellent value-for-money, but I can't afford one!

Various specialists say that limecrete is warmer to the touch than concrete - is this true?

I've no personal experience of it, but given the greater insulation value of limecrete, the statement makes sense.

If so, is underfloor heating really needed if the room has a wood burner?

That depends what you want from your heating. I presume that you don't plan actually to walk on the limcrete, but on tiles on top of it - is that right? If so, the tiles will still feel chilly to the touch unless you have UFH. Furthermore, some people like "focal point" heating - something that you can warm your cockles beside, and UFH won't give you that. With UFH you simply get a gentle overall warmth in the room. As I said, it's a matter of personal preference.

I'm afraid I can't answer your remaining questions.

 

[skier-hughes]

and by the way, some of us have cleaned and cleaned our tiles adn they are not sparkling, but are very very nice

 

[lou]

Matthewc
To supplement the very helpful posts you will get from this forum you may want to have a look at the Green Building Forum. I have spent hours trawling through that and the AECB (another helpful forum there) and SPAB information to try and get to the bottom of the listed building/heating solutions/reducing damp problems. Having finally settled on an air source heatpump (we don't have mains gas), and having recovered from the impact of the estimate for underfloor heating laid on limecrete floor, have just been told by the builder (and he, to be fair, was working on the structural enginers advice) that we are probably going to have to have most of the rubble-stone house underpinned; add another xxxx£k to the bill... The engineer is sending me some alternative ideas about putting a dpc over (or under?) the underpinning and concreting (aaarrgggh!) the floor - to save money. I'm sceptical to say the least.

We, or rather I, would also like a woodburner as a focus for the room and an additional source of heating for very cold snaps. We also have a very old Rayburn in another part of the building. After many hours of devoted attention, we now have it in reasonable working condition. It has a pump on it and a heating engineer has now given us helpful advice about how we can link all of this together using a buffer tank/ accumulator (I'm not quite sure of the difference). It's all very complicated but u/f heating is wonderful to live with and, because it operates at lower temperatures than radiators, doesn't warp any nice old woodwork you may have, and (joy!) disposes of the need for ugly radiators. I think the research is well worth doing in advance of choosing your options if only to sound less gullible when talking to builders and plumbers.

Good luck with it all.

 

[MatthewC]

I do love the advice you get on this forum; it is so helpful and in this case very personal!

- something that you can warm your cockles beside

However, in light of this advice and further research, I have had another look and think that the floor is probably level enough. Therefore, if the tiles come up nicely when I try to clean them then they will all stay, with suitable repairs. (I didn't know that this was a rite of passage.) Then it'll be heated by a woodburner and a radiator at the other end of the room. I was looking forward to warming my feet...

 

[JoceAndChris]

Good choice!

Whilst I'm sort of jealous of Lou's proposed UFH, at the same time there's nothing like the proper authenticity of seeing your breath in a period property, needing slippers, warming your hands on a mug of tea, sending off for new thermal pants.

And a woodburner seems like a necessity!

 

[lou]

Oh no! I already feel guilty about taking up the flags - please don't make it worse. Though now we are reconsidering options as a structural engineer has recommended underpinning the WHOLE area that we intend to install the UFH in. This will add a huge amount to the cost. Additionally, I am really reluctant to underpin walls that have stood solid on their own for so long.
Husband has had two creative approaches that we are running past the SE today:
1. Raise final height of floor
2. Only install UFH in the centre of the floor, leaving a margin of about 15" or so around the edge.

Any views on whether either of these might or might not work? Any other ideas?

 

[MdB]

If the floor is dug up with a 45° chamfer around the edges from current floor level which is the normal recommendation if you don't want to weaken the foundations, you should be able to get your pipes within approx 150mm of the wall. Our closest pipe is 100mm from the wall so this extra distance will make little difference. The edge of the screed on top of the pipes would be a bit weak being on a chamfer but there are ways around this. The simplest would be to raise the floor level by 30mm or so.

I am not a structural engineer so the above would very much need to be approved.

[Edit]
The above also applies to limecrete based floor. Should have mentioned that....

 

[Penners]

if the tiles come up nicely when I try to clean them then they will all stay, with suitable repairs. (I didn't know that this was a rite of passage.)

Then presumably you also didn't know that you're supposed to wear sackcloth and eat worms while you're doing it?

If it doesn't hurt, where's the satisfaction when the job is done? :wink:

 

[Moo]

Cleaning floors (of all sorts) is only one example of a rite of passage.
Perhaps we should start a new thread... ?

 

[lou]

MdB
Thanks. That's very helpful. I will share it with the SE to demonstrate that there's a precedent where the UFH is fine and the walls remain intact without the underpinning. Please let me know in the next month if your walls fall down!

 

[MdB]

Digging out the walls is very much not something to take lightly or without expertise (which I don't have). Our old walls aren't structural and are only about 20% of the building so we aren't a good example. I'm afraid I forget who but someone here got a nice job completely rebuilding a stone cottage because some monkey builders dug out too much of the floor and the whole house came down. A lot depends on your soil / ground type and the wall construction. It is very much something you need a proper expert on. However, from what you say, there may well be a good solution maybe along the lines of what I have suggested which doesn't involve underpinning.

 

[lou]

It was Gervase Webb (thanks Gervase!) I thought I had the thread stored in my 'favourites' but I think I must have worn it out showing to so many builders. They usually blanch and we don't hear from them again. The current builder we are negotiating with (and his link structural engineer) we chose because of his prior experience, witnessed at first hand by me, of installing a limecrete floor in a similar property - but one which had deeper 'foundations' than ours.