solid oak on concrete floors - which underlay?

[HelenB]

Hi, new to this board - hope I'm posting this in the right place.

We have three rooms - kitchen, dining room and conservatory - which have concrete floors, and for which we have already ordered solid oak flooring. After having read a few threads on here, we've realised that, contrary to what the man in the flooring shop said, we're likely to have a problem with the wood 'warping' if we just glue it to the concrete.

Our question is, can we use underlay to prevent this? If so, is there one particular type that would be best? It would be incredibly impractical for us to raise the level of the floors in order to ventilate, as the rooms are all different levels with loads of doors etc.

Could we have avoided this problem by choosing laminate / engineered wood rather than solid? Apolgies for staggering lack of knowledge on this subject - should have asked before ordering the flooring, i suppose :roll:

Cheers,

Helen

 

[Jill]

Hi Helen, I haven't fitted solid oak flooring to concrete but I have enquired. I was told I would need a 2 - 4mm Damp Proof Membrane, Underlay then Marine Ply all to go under the Solid Wood. I have just had some oak floor boards fitted upstairs to the joists and looking back in the book that we got it says for concrete you should attach wooden battens to the concrete. They should be 20mm thick and set at 300mm centres, attaching to the floor by adhesive or screwing to the concrete. The method of attaching the oak floor boards to the battens will depend on how wide the boards are that you have purchased. My book recommends that for upto and including 160mm then they can be secret nailed. Above 160mm then secret nailing alone is not enough and face fixing is also required. Afraid both of these methods will raise the height of the floor to some extent.

 

[yamin]

Agree with Jill here - we had solid oak floorboards put in a room over concrete. Can't comment on the DPC, although since this room was done up in the 80s I think it had one injected. Anyway, we were advised to put battens down too. I was concerned about raising the floor, but actually the difference is less than an inch in our case.

 

[Jon Maine]

There are special adhesives to stick floorboards straight to concrete, The DPC would only be needed if the concrete were damp, so perhaps best to invest in a moisture meter and test it. I admit wood on concrete does not seem natural to me, but having said that if it is stable it should not be issue. I presume it is old concrete laid for many years? Alternatively, screw batten to the concrete and fix your floorboards to these.

 

[Ushy M]

We've had a few threads on this, including one called "Laying wooden floors over concrete - how?" and "Wood flooring on UFH screed", where AMc referred to this company:
http://www.vanillawoodfloors.co.uk/index.php
This is the way we're thinking of going as there's no way we'll be digging up the existing concrete floor and we have very little headroom to fit boards on top of battens.

 

[Penners]

The key question, Helen, is whether your concrete floors already have a damp-proof membrane incorporated in them. If they were done properly, and in the last 40 years or so, they should have. If so, and if they've had a lengthy time to dry out after being laid, they may be damp free. But as Jon suggests, it would be a good plan to hire a damp meter and check. Of course, you'll only be able to test the surface, so make sure you choose a day when there's no risk of condensation on the concrete.

 

[HelenB]

Thanks for all the replies. We're starting to get a bit worried that buying 'real' wood was a mistake, even though we love it. Anyhoo, it's already ordered so we just have to get on with it.

I have no idea if the concrete has a damp proof membane incorporated. As it's a victorian house, I'd guess not. We have three rooms next to each other (but all slightly different levels :roll that need doing. The kitchen is the highest, currently wood on concrete, but no idea what's under the wood - need to take a piece up and have a nosy. The dining room is next, quarry tiles on concrete, and the conservatory is flagstones and very low (lower than ground level, so v cold and damp). We're planning to concrete over the flagstone (or remove them and concrete up) to get the floor to a sensible height, so the concrete in there will be new. Depending on the condition of the concrete under the wood in the kitchen and quarry tiles in the dining room, we might have to concrete more to tidy them up ('skim them a bit' according to our builders).

So I guess we need to 1) check what's under the wood in the kitchen (which has no warping problems at all); that might give us a clue; and 2) take up a couple of tiles in the dining room to check for damp. From there, our options are either dmp + underlay + marine ply as Jill suggests, or wooden battens. Is that correct?

We've ordered the wood flooring that clicks together like laminate, in the same sort of width strips, if that makes any difference.

We need to get this sorted asap as my husband is getting a bit anxious that we ought to phone and cancel our wood floor order asap and go for engineered instead. Our builders will be doing the work. We've looked into getting 'proper' wood floor fitters in but they cost nearly as much as the floor did, so definitely no go. :shock:

Thanks again

 

[Moo]

There are several things about your post that (for me, at least) have rung warning bells, so please be prepared for some kindly-meant finger-wagging from them as really knows about such things -

I have no idea if the concrete has a damp proof membane incorporated. As it's a victorian house, I'd guess not.

I think it's unlikely that the concrete is original to the house (let alone damp proof membranes, which are much too recent).

We have three rooms next to each other ... that need doing. The kitchen ... currently wood on concrete, but no idea what's under the wood

I don't quite understand this; if you've no idea what's under the wood, how do you know it's on concrete?

the conservatory is flagstones and very low (lower than ground level, so v cold and damp). We're planning to concrete over the flagstone (or remove them and concrete up) to get the floor to a sensible height, so the concrete in there will be new.

Planning to concrete over flagstones is, on PPUK, is as bad as saying you're planning to replace the original sashes with UPVC windows!!! You will get masses and masses of really good advice about this. Please, oh please, listen to it, ask more questions, and listen to the answers.

we might have to concrete more to tidy them up ('skim them a bit' according to our builders).

The same builders must have been in our house several decades ago. All the lovely flagstones and pamments had been 'skimmed a bit' and it took quite a bit of work to chip and scrape it off and let the floors dry out.

It sounds to me that some serious damage may have been done to the poor old place already, so don't listen to your builders who obviously know nowt about old houses. Instead, listen to the experts here.

xxx M

 

[JoceAndChris]

I am so glad you posted that Moo, kind sentiments kindly expressed.

HelenB - forgive me if I seem nosey but what is your rationale behind wanting all your floors to be modern oak? Aren't the flagstones and quarry tiles more charming and interesting, quite apart from being the intrinsic history of your house? Or are they modern cement-y copies of flags and quarry tiles? Pics would really help here!

I merely ask because up until fairly recently I had a notion that floors should be of a oneness and flow seamlessly from one to the other. I think it was hard to have my expectation of what floors should look like challenged but some very generous people here convinced me how wrong I was! http://www.periodproperty.co.uk/forum/viewtopic.php?f=1&t=10450&hilit=please+help+me+understand+my+kitchen (the discussion I refer to happens in the first two pages of this thread). Not only has the history of the house been preserved, but also a whole load of money, time and effort saved!

It may be that we just have not understood your post.

 

[HelenB]

Moo, thanks for your reply. I'll try to respond to each point below (please bear in mind this is our first house that we've owned and we really know nowt about any of this )

We have three rooms next to each other ... that need doing. The kitchen ... currently wood on concrete, but no idea what's under the wood

I don't quite understand this; if you've no idea what's under the wood, how do you know it's on concrete?

Sorry, i got that round my neck. We know it's concrete because my husband took up a block of the wood and saw it. What i meant to say is that we don't know whether that concrete is newer and has any damp proofing. Half of the kitchen is a newer (last 10 years) extension, so the concrete may have been laid then.

the conservatory is flagstones and very low (lower than ground level, so v cold and damp). We're planning to concrete over the flagstone (or remove them and concrete up) to get the floor to a sensible height, so the concrete in there will be new.

Planning to concrete over flagstones is, on PPUK, is as bad as saying you're planning to replace the original sashes with UPVC windows!!! You will get masses and masses of really good advice about this. Please, oh please, listen to it, ask more questions, and listen to the answers.

We'd much rather remove the flagstones - and still plan to do so if we can. We've been told that concrete takes X amount of time to dry per mm depth, so we're concerned that adding depth (the depth of the flagstones when removed) will slow up the project even more.

we might have to concrete more to tidy them up ('skim them a bit' according to our builders).

The same builders must have been in our house several decades ago. All the lovely flagstones and pamments had been 'skimmed a bit' and it took quite a bit of work to chip and scrape it off and let the floors dry out.

It sounds to me that some serious damage may have been done to the poor old place already, so don't listen to your builders who obviously know nowt about old houses. Instead, listen to the experts here.

xxx M

Our poor builders happily accept that they don't really know much about older houses but they've done a grand job so far, it's just this flooring business that's foxed all of us. I'm not sure I'd say that the place had already had 'serious damage' done to it...though the previous owner was a bit of a 'tinkerer', hence lots of, um, quirks.

 

[HelenB]

Hi Joce,

Thanks for your reply. The flagsones and quarry tiles are indeed very charming, however they are horribly cold (especially the flagstone which the previous owner placed below ground level in a conservatory - hence a soggy cold room). We want to warm and lighten the place up a bit.

The three rooms are in a sort of triangle, with both the kitchen and the conservatory coming off the dining room, and with a doorway between the kitchen and conservatory (does that make sense?), so we wanted to bring them all together as sort of one living space (sorry, i know that sounds a bit like TV property show talk). The conservatory has never been used since we moved in (2 years ago) and the dining room is so cold and unwelcoming that we end up hiding in the lounge for TV dinners

We are planning to knock out the existing kitchen (which is falling apart - we *will* be replacing with something sympathetic to the age of the house), so we thought it made sense to do the whole lot at the same time.

We are trying really hard to maintain the charm of our house in lots of other ways, so this in an area where we have decided a compromise would be ok. These rooms might look 'authentic' victorian at the moment, but they're just not getting used

 

[JoceAndChris]

Dear Helen

Thanks for your generous reply. Believe me, I know exactly how you feel and why you've chosen to do this. I've got the same situation downstairs, and as I said, had all sorts of plans to bring the floors together and make the kitchen and dining area warmer and cosier, until I realised what a wrong-headed decision it would be.

I beg you though, do something temporary rather than hack up old flags or quarry tiles. Once gone, they're gone- and you're talking about features that many would cherish, and that really add to the atmosphere, and value, of your house. Rugs, rush matting , increased heat, curtains, do wonders for cosiness and liveabilty. Don't buy an old house and turn it into a new one, learn to love what you've got and make it work for you.

If you have damp there, that's a different issue that you need to tell us about!! Concrete is only likely to make that worse; I curse my concrete floor every day, in another section, that pushes all the moisture into the walls and is literally causing them to crumble away.

I'm not wanting to pour cold water on your taste - I'm sure oak floors would look great and could be the quickest answer but no-one with a conservationist attitude is likely to praise you for it.

 

[Penners]

We've been told that concrete takes X amount of time to dry per mm depth, so we're concerned that adding depth (the depth of the flagstones when removed) will slow up the project even more.

In which case, here's a suggestion to avoid any delay in dealing with that flagstone floor.

Instead of taking up the flagstones, or (worse still) concreting over them, why not lay battens on top of them and then lay your wood floor on top of the battens? That way you will conserve the old flags and still get your wish, as regards your floor preference.

And what's more, it'll be a quick process.

 

[yamin]

Hi Helen

You got some great advice above. Can I add my plea not to take remove the flagstones? Joce has some great suggestions for warming them upand you obviously like living in a period house,so it would be wonderful to retain those rareand possibly exquisite quirks and differences that make an old house so lovely. If your flags could be 'warmed up' (rugs etc), and restored enough to bring out their real beauty,would that change your mind? Do you need a few PPUK pics to help you decide?View attachment 1

and after



Sorry everyone for repeat of these two pics. This room was cold and damp, but with flags cleaned and oiled and a nice rug down,its really cosy. It is in the middle of a run of three rooms, the one next to it on one side has an oak floor, laid by us (incidently, the fitters are worth every penny, but its a skilled job to do welll, so you do have to build it in to your calculations - I would worry how clip together boards will look) - and its at a slightly different level. The other side is a modern extension kitchen with slate grey ceramic tiles. I think the three floors look great togetherand serve to emphasise the 'interestingness' (excuse my liberties with grammar!!) of this period property. You mentioned 'house makeover' yourself - and you are right - you are in dangerof it looking too jarringly 'madeover' if you force it all to be too streamlined - and it may just make the other period features look 'messy' and disjointed! I say, assuming you can warm it up, celebrate the different rooms you have!

 

[HelenB]

We've been told that concrete takes X amount of time to dry per mm depth, so we're concerned that adding depth (the depth of the flagstones when removed) will slow up the project even more.

In which case, here's a suggestion to avoid any delay in dealing with that flagstone floor.

Instead of taking up the flagstones, or (worse still) concreting over them, why not lay battens on top of them and then lay your wood floor on top of the battens? That way you will conserve the old flags and still get your wish, as regards your floor preference.

And what's more, it'll be a quick process.

Hadn't thought of that, thanks for the suggestion. However, the floor is very damp at the moment because it is below ground level - it's like a patio indoors, and is making the room smell yukky and damp (In actual fact, we'd always just assumed that there was concrete under the flagstones but, as i said, the previous owner was a bit of a tinkerer. Given the amount of damp in there, I wouldn't be at all surprised if we lifted up one of the flags and just found soil! ). We were advised that raising the floor (by using concrete with damp proofing) would solve this problem. If we were to just put wooden battens down over the flagstones, we'd still have the smelly damp problem wouldn't we?

Apologies for all the newbie questions

 

[yamin]

Oh, and we have manky old quarry tiles in our hallway, which I was delighted to find! Funny that, but sure my fellow PPUKers will understand!

http://www.periodproperty.co.uk/forum/viewtopic.php?f=1&t=10440

 

[yamin]

I wouldn't be at all surprised if we lifted up one of the flags and just found soil! ). We were advised that raising the floor (by using concrete with damp proofing) would solve this problem.

Most flagstones were laid to earth back then. Ours certainly are. By laying rubber backed carpet on them the last owner had created a smelly damp problem.Flags laid to earth are specifically meant to be a source for damp to be removed - i.e. the floor can breathe and if not covered up then any damp that is in the room will evaporate through the floor. By covering it up with a non breathable carpet this process is interfered with. At bestyou get a damp smelly carpet, atworst all damp is driven up your walls! Did the last owner have a carpet down? If so, please give the flags a summer, they will dry out given time and good ventilation, ours did.

 

[Moo]

There - I told you, didn't I? All the mother (and father) hens are hopping off their perches simply dying to help.

And, just to add to the confusion, here's another thought: we've not yet brought up the subject of the dampness. Your first priority should be to try to discover what's causing it and, if it's possible, put it right. If it's not possible, there is a whole variety of ways in which you can improve the comfort of those rooms* and you will have to weigh them in the balance, according to how much time, energy and money you have available.
In an ideal world you would, of course, dig up all that concrete and start again with more sympathetic materials......



* the words 'underfloor heating' keep coming to mind

 

[Moo]

Yamin - I can go four better than you on that score. Our flags (and pamments) were covered with a cement screed + red tile paint + lino + foam rubber underlay + plastic-backed carpet.

And, like yours, once they were uncovered they dried out a treat.

 

[yamin]

Yamin - I can go four better than you on that score. Our flags (and pamments) were covered with a cement screed + red tile paint + lino + foam rubber underlay + plastic-backed carpet.

Show off!!!!

Thats a pretty radical cover up! Are you sure there wasn't a body under there as well?? :shock: