flooring dilemma

[adamfausset]

Hello, wonder if you can help. I'm about to fit a new kitchen in my 17thC farmhouse. Before I do that, I need to sort the floor. Underneath three lots of lino is a scree floor. Much to my disappointment after digging down, it was just earth, stone and general dampness beneath. The scree is ok, measured 16% on the damp meter but its been under lino for 60 years with no means for escape, so it might reduce alot if I allow the floor to breathe. Clearly the floor needs to breathe as the walls are damp(ish) again about 17% and the bottom of the wainscotting is quite rotten, clearly as the moisture in the floor can only escape to the walls due to the lino. Finally the floor undulates gently max 3-4mm in places. Sorry long copy needed to set the context! So, I want to put an oak t&g floor down on battens, as I want the nail holes. The problem, is to do this, it will raise the floor level by 2" and the ceiling is very low already. If I lay the timber without battens I lose the patina of the nail holes. The other point is that the timber floor guys said that I needed to lay an damp proof insulation layer beneath the flooring to prevent damp in the floor warping the oak, where as the one reason I wanted an oak floor was to allow the floor to breathe a little to help out the walls. Would be good to know if anyone out there has an answer to this, do I lay the oak and hope that the moisture is not enough to damage the oak or do I lay porous tiles and not worry about the undulating floor?

Many thanks
Adam

 

[JoceAndChris]

Very tricky decision for you - personally I think an undulating modern tile floor would be very strange and may not work, though if you want to put down old reclaimed flagstones then they get away with undulations. I think you should go for flagstones -perfect for a kitchen! Wouldn't oak really suffer with splashes and spills and that hot pan you plonk down when every surface is full?

We have 19th C elm floorboards here on the ground floor and the house has suffered with the usual damp problems. The floorboards are fine, but they're suspended above ground with plenty of air circulating beneath.

What's your screed made of?

 

[middi]

It is not advisable to lay oak floors directly above soil or existing floors that is likely to get damp, it will play havoc with the new floorboards.

If you live in an " old" building where floor damp proof memebranes or wall damp courses were not the order of the day then you have to improvise if you wish to have oak floors.
In order to get the best from oak floors, and to keep them in good condition, they need to be kept dry. If they are to be fitted in a situation where the subfloor is likely to get damp then provision has to be made for good ventilation to disperse that damp that may accumulate below the boards.

If you are presented with a situation where the ceiling height is already minimal, you may have to consider lowering the existing floors, insert adequate vents at base wall level ( below floor) and suspend the floor on new installed joists. This will give you the opportunity to insulate below the new floor boards with plenty of ventilation do dissipate any excess moisture even at base wall below floor level. This is a well tried and tested method.

You can certainly lay the boards on a new installed DPM, under new floor battens and then the boards. Whilst this will safeguard the new board to a very good extend it will do very little ( or even aggravation) to the transfere of moisture into the side walls. Also if you intend to use this method there is little scope to add futher insulation due to the existing minimal ceiling height.

You may want to consifder limecreed ( as opposed to a concrete screed), but this will not solve the dampness perculating through this " screed" under the floorboards, (albeit better than bare soil), this will also involve lowering the floor due to you ceiling height problem.
There are lots of old houses and cottages where " paviours" or " stone" flags are used in floors with no damp barriers installed, these perform best if they are laid with butted joints, ie-no mortar joints allowinf for moisture to evaporate and finally managed with judicious ventilation and heat.

Also an apllication that appears to be incorrect in an old building ( and it usually is !!!) it may work perfectly well on a similar building simply due to the fact that the " dampness" factor are not equal in these old buildings.

Middi

 

[Zebra]

adamfausset, I have a very similar situation. I don't have any answers for you, but can share my own thinking (so that others can tell me it's all wrong and won't work!!). First of all though, I didn't understand - is your floor concrete?
I have a concrete floor in a 17th C cottage. Underneath is soil. I've taken it up around the edges, to help the walls to dry out, and make a breathing trench for moisture to escape from under the slab without going up the walls. This will in due course be filled in with limecrete, but I'm not putting in a complete limecrete floor.
I can't install a suspended floor because of headroom.
I too would very much like an oak floor, but it is pointless installing an oak floor if there is any damp at all, because it will just curl, and so with this breathing trench, it can't be done. I was thinking of having an edging in a different material from the middle bit, but am not sure if this would look weird. The edge would be breathable, prob clay tiles, and then on the middle bit I'd install a dpm directly ontop of the slab, and have t&g oak flooring, with the dpm somehow carefully turned up around the edges.
Otherwise, it's just a slate or flagstone floor.
Don't know if this is relevant for you at all!...

 

[Pford75]

depending on which part of the country you are in, a pamment floor (pref. reclaimed) can look fantastic and be breathable.

I certainly wouldn't lay timber over a floor which you know to be damp.

 

[Moo]

The simplest thing would be to follow Middi's sage advice and put pamments straight on to the earth. They are ideal for places like kitchens, and you won't have to worry about damp at all.

 

[Zebra]

Pford75, why do you say "depending on which part of the country you are in"? Is it because pamments are traditional in Norfolk and Suffolk? In which case, what is the difference between a floor brick and a pamment?

Edit: And in which case, if I'm in Hertfordshire, would they not be suitable? I've got an example of what I think are my original floor bricks, and they're all different shapes, and I'm not sure which they are!

 

[adamfausset]

thanks for all the responses. Very useful. Clearly the oak flooring is an issue. I'm familiar with the limecrete method but its a huge amount of work to do this plus add ventilation etc. It seems the most sensible route is the pamment floor, I've just looked at some images of them and they are beautiful, you can get some very light coloured ones as well. The key things is that they are not too thick, i.e no more than an inch thick otherwise I'm back to the problem with the ceiling height. So would I be right in saying that I could lay pamments bedded in a lime mortar and grout them in a fine lime / chalk mix. Presumably this would then allow the floor to breathe through both the pamments as well as the grouting. I could also do as Zebra suggested and cut around the floor by the walls and lay limecrete. Does this seem like a workable plan. I guess the potential issue is still the undulating floor, or do you think because the pamments are of differing colours and somewhat 'rustic' I'd get away with it?
Adam

 

[masochists-r-us]

Hi Adam,
Depending on whether your house is a 'rough' or 'smooth' (read Hugh Lander's Do's and Don'ts book and you'll understand - our early 17th C stone farmhouse is something in between the two) you should be going for stone flags or old quarry tiles / pammets / floor bricks as these will give you a look and finish which is both practical and authentic. In a house the age of yours, you would most likely only have found a timber floor suspended above a cellar on the ground floor. On the first floor however, oak/elm planks would have been the norm.

 

[Moo]

I guess the potential issue is still the undulating floor,
Adam

Would it be very difficult to level the floor?

 

[Pford75]

Re: flooring dilemma

by Zebra » Mon 5th Dec, 2011 7:05

Pford75, why do you say "depending on which part of the country you are in"? Is it because pamments are traditional in Norfolk and Suffolk? In which case, what is the difference between a floor brick and a pamment?

Yes - I was thinking that pamments are very traditional kitchen flooring in East Anglia. But this shouldn't dissuade you from considering it elsewhere. My understanding is that pamments are typically square(ish) clay tiles usually found in 9x9 or 12x12 inch sizes. My kitchen floor is 12x12's which are laid directly on to earth. Here's one before they were cleaned

 

[AMc]

I'm not at all convinced that pamments in themselves are "breathable". The ones I have lifted and relaid in my vinery were very hard, fully fired ceramic and showed no indication of any porous nature whatsoever. You could have left them in a bucket of water for a month and they would have absorbed not a drop.

The floor bricks we laid in the kitchen were the same until they were split with a masonary saw - that exposed the inside which had enough suction to prevent them sticking to the lime mortar (grrr). The face surfaces are very solid and didn't suck up any moisture even before we Osmo polyx'ed them to improve the finish.

I also struggle to see how flagstones would be porous without also being too soft to be practical but I don't have any so may be wrong.

Obviously if you have joints with silver sand or lime mortar then that will be able to move moisture. By using smaller 'tiles' you get more surface area to move moisture.

If you bed the lot on a modern tile adhesive then IMHO it will be as unbreathable (?) as a concrete screed.


In case you don't know - if you are planning on doing serious work you may need building control approval/building notice - unless there are strong reasons why it's uneconomic or your house is listed then a building control inspector may require you to dig out and insulate.
What you are planning could easily be regarded as "renewing the thermal element" a.k.a. the floor.
Plenty of people ignore this which is their choice, but don't get out the sledgehammer without at least knowing there is a potential pitfall.

If it were mine I would seriously consider the full excavate, ventilate, insulate and then install the oak flooring you want. You can probably grab an inch or two of headroom if you choose and doing anything to your floor is going to be expensive and disruptive so I would go for what I wanted. That's just what I would do though.

 

[adamfausset]

Having spoken to a few specialists on this now and viewed how beautiful pamments can be (very expensive mind), I think perhaps this will actually look better than oak, so I'm going to do the following : cut a channel around the concrete scree, 6" back from the wall, 6" deep, fill it with lime and Lica, this will enable moisture to evaporate before it gets to the wall. Level the floor where required with lime / course sand, lay pamments treated with linseed oil on to a lime / course sand mix then grout also with lime. I think this will give a beautiful look, allow a degree of breathability in the floor through the grouting if not the pamments and at the same time reducing the amount of work involved. I see this as floor covering replacement, not floor replacement if I had to speak to building control. Which I wont!!
A

http://www.pamments.co.uk/

 

[tobydog]

Adam - In the 6" channel you are cutting out, will you fill this with a Lica base (say 4" deep) topped off with lime / sand mix, or will you mix the Lica with the lime / sand as suggested on another thread?

I'm digging a channel as well but taking a shortcut and only removing the rubble and cement infill that the earlier 'renovating' builder applied between the concrete floor and the original plinth wall. I can't afford to go further. At best this is just 3" wide and goes down to nothing in places as it reaches the wall (not very square!). The maximum depth is about 12" but only a few inches where structural brick shows up.

Interesting thing happened yesterday. I took some gypsum plaster off part of the wall where it was making contact with the floor. I took off about 12" and found some modern block work underneath. I had an idea it was somewhere there from earlier drilling, however, there was air coming through some of the gaps in the mortar :shock: Rather breezy to the extent I easily found the source outside under the bell drip. Explains some of the damp showing up on the plaster. Kitchen towel was the emergency fix.

 

[adamfausset]

tobydog, yep, I'm going to mix lime with lica balls (2-5mm) with a ratio 1:3, 100mm deep, if I dont use lica and use course sand then I'd need to do the job in two parts, 50mm each time. With lica balls it will set in about 2 weeks even using NHL 5. I guess thats the joy of working on these houses, you never know what you're going to find and whilst everything takes 4 times longer than you expect the joy is in the thinking and learning about how you're going to solve each problem. Brilliant. A

 

[tobydog]

On the other thread (Dehumidifiers!) MdB said he used 1 part NHL 3.5, 1 part sand, 1 part 0-to-4mm, 1 part 4-to-10mm, 1 part 10-20mm of Leca otherwise you end up using a large amount of lime to fill in the gaps between the Leca balls. He didn't know whether it worked because he then used slate as the flooring but it is an alternative take on the idea.

 

[MdB]

Leca not lica

(Lightweight Expanded Clay Aggregate - I think)

 

[tobydog]

I caught it on the rebound. Didn't think it looked right.