I need to convert an outbuilding into a usable room. The building is
very solid, as it used to be a utility room (150 years old). It has
old broken floor tiles on it at the moment, and is very uneven. It has
about 40 mm drop off to one side. I need to level this floor somehow.
It is a rented house, so it doesn't have to last too long and I need
to keep the cost down. What is the best and cheapest way for me to lay
I thought about laying a wooden floor onto some joists, but this will
be tricky with the uneven floor. Or laying down some concrete and then
chipboard covering, but I've never worked with this much concrete
before. If I go the concrete route, what is the cheapest way to
install damp proof? Can I just coat the concrete with bitchumin?
Loads of questions, but you get the drift....low cost and ease :)
Does anyone have any suggestions?
If you have th edepth, and the existing floor is stable, you can lay a
plastic membrane over the lot and SCREED rather tha concrete it.
Screed is a rather weaker sandier mix, that is laid very dry so it
doesn't slump. Its also very porous, and not very strong. very large
areas benefit from reinforcing mesh. You can get the big rod stiff, or
smply use chicklen wire - anything helps.
You lay ir by making and smoothing out the deges at teh right level
using spirit levels and long bars., then fill in the middel.
If you are good with a float, it can be carpeted or vinyled straight
off. If its rough, tip levvelling compound on it later on.
What kind of floor area are we talking about and how high are you thinking
of bringing the floor from it's current setting? Early thoughts are that
concrete will be cheaper and easier. Is the current floor susceptable to
damp? I just wonder why you mentioned damp proofing?
oh and don't use chicken wire*, it'll be a bugger to get it to lay flat, the
proper reinforcement, if needed, can be bought from good builder's
merchants. Some chopped strands of fibreglass can be added to the mix along
with a plasticiser and, or Latex, which will strengthen any thinner layers.
*unless of course he sticks the chicken wire down with car body filler
....... eh TNP? ;-)
Thanks for the tips, a couple of questions though...
What kind of sand/cement mix would the screed be?
The area is about 5ft x 10 ft, so could I do this ok without mesh you think?
Do I have to use special waterproof 'membrane', and do any joining edges
have to be glued in any way? The only reason I ask about waterproofing is
just incase it does allow damp through. It's a new house, and I know nothing
about it :)
Finally, It's just a cold outhouse at the moment, what's the best (cheapest
:) ) way to insulate the floor....with polystyrene?
that would depend on the thickness you are thinking of laying to
once again depends on the thickness
you can get DPM in 1 sheet, much larger that you require so no joins
necessary, if you need it and the building doesn't already have it, which, I
would have thought, it should. A DPM should really be layed as the base is
constructed and go under the walls, if you do as you say and there is a damp
problem, you will transfer it to the walls. Without seeing it, it's hard to
say, but it sounds like you would be best to leave it to breathe.
how were you thinking of using the poly? layed on top and then a floating
how far are you prepared to build the floor up? ... and how out of level is
It's hard to say. I would say one side of the room is probably 30-40 mm
(max) lower than the other (the width). Do I just build it to the level of
the higher side or above by 10 mm or so?
The area is about 5ft x 10 ft, so could I do this ok without mesh you
Regarding the damp problem. As I say, it's just an old outdoor utility room
(circa 1875), with (slightly broken) tiled floor. Is this likely to have any
kind of damp proofing?
I have plenty of headroom, and a step up would keep the rain out, so rising
up a few inches is not a problem. As I say, at max there is a 40 mm
difference. But it does undulate.
The point to all this is that we are living in rented accomodation on an old
estate. We have to move to another house for complicated reasons, but the
house is so nice we just have to have it. Problem is, it doesn't have any
rooms available for my office, and that's what this room is all about. I
need to keep the price down for obvious reasons (as the estate won't help),
but it's only for a max of 5 years. After that it matters not if the
building rots away :). Until then, I want it warm and dry.
Sorry for this deluge of questions, but I suppose my alternative is the get
the builders in, but that defeats the challenge, and increases the cost.
For all your concreting questions go here;
It's tough to say without seeing it as to whether you are already
damp-proofed, or whether you need to, but gut feeling is not to bother,
especially as there are tiles there already, as well as the risk of sending
any moisture up the walls (is there a damp course on the walls?). Level the
floor off, let it dry out for a week or so then lay an insulating foam and
put your floor on top, either tongue and groove, or if it's 10 x 5, and you
can get it in, you can buy sheets at 10 x 5, though this might be a pain to
lay as one sheet. I wouldn't use polystyrene , polyurethane foam might be a
better idea. If you are worried about the damp, then lay something between
the foam and the chipboard (if that's what you are using). if you want to
insulate it even more then 50mm x 50mm framework of treated timber with 50mm
rockwool sheets between the frame should guarantee no cold comes through the
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