hobgoblins

Due to the damp coming up through the tiled floor, a couple of years ago I removed the original tiles, two layers of concrete and some of the thick clay like mud also ... a bit too much mud as I misunderstood what my neighbour said and I dug out approximately 30cm instead of 20cm. Two years on and the clay was solid and well flattened so I asked my neighbour to order a truck load of stones to use as the base under the new concrete and it isn't quite what I expected as it looks nothing like the aggregate used in the UK, it's much finer ... a few of my friends in the UK say that it looks more like the material that would be mixed with concrete and not put underneath it. It doesn't give me assurance that my neighbour that ordered it had asked if he could also have some for a new path and I told him that he was welcome to take what he needs ... and he now tells me that he will mix it with the concrete and not put it under the concrete path ! He also says that he hopes the weight of the 20cm of concrete going on top of this in my room doesn't cause the floor to sink ... brilliant ! Obviously I will hire a machine to flatten it down once it has had time to dry out as at the moment, it's more like porridge with pebbles in it !
Hoping someone can confirm that this is the correct material to use in Hungary ... I certainly wouldn't want to have to remove it again !!

Jack_Russells4ever

I cannot answer your question about the gravel in the photograph but this leads me to ask a question for anyone that knows.

What would be the problem with pouring a beton floor in a room with an old floor that needs to be replaced and using some of the black or clear thicker plastic sheeting that is sold at some builders merchants? I am not talking about the thin sheeting sold at many places nor am I speaking about the rubber membrane used under shower floors. Seems like plastic sheeting between the gravel and a beton floor would stop a moisture problem..just my thought.

hobgoblins

What I'm intending on doing is when this has dried out sufficiently allowing me to flatten it down and compress it enough is to put a 10cm layer of concrete over it, let it dry and then put down the damp proof sheeting and lap that up where it meets the walls ... then lay the steel mesh on top followed by another 10cm of concrete. Once that is fully dried, I can then lay down the final floor covering, probably a vinyl of some sort ...
I couldn't remove just the old tiles and the old concrete before as the damp proof course in the brickwork was below that and slightly below the surface of the original mud base ...

farka

Preventing the moisture from rising up through the floor means it will try to go sideways and up your walls. So ensure that you have adequate damp proof foundations under your walls above the height of your damp-proofed floor level. This can a a problem in older clay walled village houses.
HTH

hobgoblins

Yes, the dpc can be seen running along between the bricks so I intend to paint along that with a sealant and lap the damp proof liner up the walls to just above where the dpc in the bricks is and put more sealant along the top of the material ... that should prevent any damp from being able to come up either the floor or the walls ...

farka

Sounds like a plan... jó munkát!

Peter_in_Hungary

What I would do (assuming your measurements re depth are correct) is flatten the sub soil and then check it for level and fill in any hollows with sand and remove any high spots (or fill with sand to the level of the high spots). I would then put 8 cm EPS 100 grade (no point in using XPS as any moisture getting in will stay there whilst EPS will drain out and test show that EPS is better under ground) Then put 2 layers of thick black plastic over and up to the walls. Then lay 12cm concrete with steel mesh. Take care not to hole the black plastic i.e. use boards when wheel barrowing cross it.

If you have an adobe wall then do as above but leave out the black plastic.

If you do as above then you will have an insulated floor which will be much better in the winter

The photo shows standard all in aggregate as used for mixing concrete. There would be no problem using if as infill other than it does not tamp down tight which means you need to use boards to run the wheel barrow full of cement across it.

Edit to say
just read the 9:03 post - do as you say with the DPC and ignore the bit about adobe walls in this post

Peter_in_Hungary

Plastic sheeting as DPC is OK. I use double thickness to be sure. Also blind the gravel with sand to better protect the DPC. Also as above if you have the depth put in some 100 grade EPS under the concrete as insulation. anything up to 15 cm will help. more = better insulation, more than 15 cm isn't worth the extra unless you have to fill the space. (it's cheaper than laying concrete) even 2 cm will make a difference.

hobgoblins

Thanks Peter ... the mud had been standing for two years exposed to the air and had been walked on many times so was rock solid although not without a few dips and bumps ... a bit late to do anything about them now though as they are buried beneath the stones / gravel ! I was just concerned whether this was the correct stuff that my neighbour had ordered on my behalf as it looks different in appearance to what I've seen used in the UK which tends to be more like small pieces of rock / hardcore. As you said, it is an aggregate used for mixing concrete which is what my neighbour wants so I suspect that he compromised on this as something that would work for both of us rather than order what would be specific to my needs ! I'm not sure what EPS is though ? As it stands before compressing the aggregate down fully, I have about 10cm from the top of the aggregate to where the dpc runs through the brickwork and another 10cm above that ... I will do as you suggest though and put a layer of sand over the compressed aggregate before laying the damp proof sheeting ...

hobgoblins

Edit for above post ... so I've looked up EPS and see what you mean Peter ... if I decided to add EPS, would it go between the first layer of concrete covering the steel mesh and the final second layer of concrete ?

Peter_in_Hungary

The EPS goes instead of the first (bottom) layer of concrete. If you are going to insulate the floor with EPS then this should go on a flat base so level off the dips with sand. The steel mesh should be WITHIN the second layer of concrete.

Depending upon the size of the floor 10 cm of concrete may be enough otherwise 12 cm (if it is a big room then even 15 cm) Only one layer of concrete is needed.

To work out the thickness of the various layers start at the finished floor level e.g. tiles 1.5 cm then say 12 cm concrete, = 13.5 cm so far then what ever is left is infill either EPS or aggregate.

The DPC goes under the top layer of concrete and comes up the wall to meet the DPC in the wall. If the DPC in the wall is lower than the bottom of the concrete then the DPC goes below the EPS or aggregate and up the wall to meet the wall DPC. If the DPC is below the aggregate then care has to be taken not to damage the DPC with the aggregate.

EPS comes in various grades, 30, 80 and 100. The numbers refer to the compressive strength of the EPS. 30 is soft and can be used for in stud wall insulation or under wood floor where the wood planks are supported on battens, 80 is used for external wall insulation and 100 is used for floors under concrete and under clik-fit flooring where no battens are used. 30 grade is sometimes not stocked so 80 grade is used in its place. The price goes up with increasing compressive strength.

hobgoblins

Thank you for the explanation Peter ... I will have to see how much the aggregate compresses down once I've allowed it to dry out a bit ... whilst it looks quite even, the depth between the surface and the DPC running through the brickwork varies between 12cm and 16cm along the edges at present, roughly, which will be even less if I lay a covering of sand so I would need to be careful that no part of the EPS comes above the DPC level I guess ... although I will be painting over the DPC line with a waterproof sealant to allow plenty of room for lapping up the edges of the damp proof covering. I wouldn't have much room to play with and wish I had known about this before I added the last layer, 5cm, of aggregate ! It does have the advantage of being a lot less heavier than concrete and anything that reduces weight and lessens the chance of the floor sinking is a good thing !

Jack_Russells4ever

Peter, thank you for explaining this to us about the EPS and the flooring DPC methods. Much apreciated.

Peter_in_Hungary

I've just done a quick and dirty u-value for floors, to do properly the heat loss for a floor has to take into account the ratio of perimeter to area, these figures ignore that but gives you an idea (u value is the amount of heat loss / m2 in watts for each deg C. temperature difference between the inside and the outside of a building element (wall roof etc.).
floor make up, top down
Tiles......... concrete 1% steel ............insulation............... aggregate............... u-value
10mm.......... 120mm ..........................100 mm............................................... 0.36
10mm ...........120mm...........................80 mm................................................ 0.43
10mm.......... 120mm ..........................20 mm ................................................1. 2
10mm.......... 120mm............................................. ...........100mm................... 3.2

From this you can see the difference between 100mm EPS and none is just about 10 times the heat loss and even 20mm EPS makes a significant difference

hobgoblins

Thanks for that Peter, useful to know. I have no idea what EPS looks like physically but it did make me think of this stuff ... I have quite a few off cuts of two different thicknesses ... the best way I can describe it is like a kind of pummice stone material ! I have been curious as to what it is since I bought the house and if this is actually EPS, then I suspect the previous owners used it under the only room in the house that has a decent smooth concrete floor and doesn't have any damp issues !