How to install reclaimed oak floor

[Zebra]

Another question about acclimatising this flooring: my house is not currently heated, and gets very cold. I will have central heating one day, but not until after the floor is laid. If I acclimatise the floorboards indoors for two weeks in a cold house, what will happen to them when I get central heating?
The boards are inch thick solid oak, probably around a hundred years old.

 

[88v8]

I laid an oak tg floor in our conservatory in 1991. The boards were from a house built 1900 and were over an inch thick.
Then we laid more in our library, floating floor.
Then we moved and left them all behind.
I used the last of them a year ago here to floor my new woodshed.

In the conservatory, the underfloor was concrete, no screed. I laid, as I recall, 2x2" on it, floating, and nailed the boards. Oval nails, I predrilled every hole slightly undersized to the nail.

I used a floorboard cramp- hired - to ensure the boards went in tight.
http://www.tooled-up.com/product/faithfull-flooring-clamp/139953/?Referrer=googleproductlisting&gclid=CMCPq5LCkbwCFRMgtAodI1wANw
Near the edge, where there was no space for the cramp, I screwed a batten to the 'joist' and used a pair of folding wedges to cramp up the board(s).
There are cheap and nasty ways of cramping, involving chisels.

Around the edge there was a gap covered by the skirting.

The floor never moved or shrank, despite the huge temp and humidity changes one gets in a conservatory.

Last weekend we stayed in a hotel - might post about it as it was very old and lovely - they had put a new bathroom in less than a year ago, raised floor for some reason, with wide oak tg, must have cost a mint. Where the heating pipes ran underneath the tg has either shrunk or split, must have been getting on for an inch of movement, some of the tongues had come right out. It will all have to come up again I think.

Normally, heating pipes are not an issue. In concrete, the concrete acts as a heatsink, under a suspended floor the ventilation takes the surplus heat. Under your floor it will have nowhere to go. So, I would not only insulate the pipes well, perhaps with this
http://www.pipelagging.com/pipe-insulation/armaflex-solar-pipe-insulation-high-temperature-outdoor/armaflex-ht-19mm-wall
(yes, it's expensive) but also lay a sheet of aluminium under the boards, along and at least a foot either side of the pipes to prevent local heating.
Otherwise it will ruin your floor.

Btw, to pre-acclimatise your boards, you need to lay them out. Stacked won't do it. Stacked in stick is OK.

Btw 2... if you need to butt them end-to-end, the boards I used had been slant-cut so I did the same. No gaps. Probably a pointless refinement.

Btw 3... although the boards all came from one house and were the same width, they were not all the same thickness, also the height of the tongues differed. I had to pre-sort them. What appeared an ample quantity, in the end I was scratching around.

Edit... from an unheated space to a house that will be heated. Hmmm. They're well seasoned so shouldn't have expanded too much in store. Back in the day when I was fanatical about doing everything properly and time meant nothing, I'd have found somewhere heated to keep them for a few months, then layed them in small batches so they had no time to expand. But...if you cramp them tight - use an offcut of groove so as not to crush the tongues - they'll probably be OK.

Ivor

 

[Zebra]

Thank you Ivor. I shall heed your advice about the heating pipes, it's not something I had imagined would be an issue. Perhaps one could create a localised heat sink in concrete, just around the pipework. Where would one get hold of sheets of aluminium, do you think? Would the aluminium not just heat up to the temperature of the pipes?
So boards shrink with warmth then, not expand. I had thought it would be the other way around, but I see now.

 

[Toby Newell]

Cut the tongues. You will never get a close fit, like putting back an old engine and putting the valves into a different cylinder,each board will have moved to fit it's neighbour.

Cramp them and secret nail them at 45 degrees, this will allow for a small movement but still hold fast, secret nailing is not done as a time saver, it is done as the most efficient method and has been used for over 100 years.

Using a gas fired nail gun is a time saver and is incorrect however, you need serrated sharks tooth nails. The D ring annular nails from a Paslode type gun will work loose.

Acclimatisation for 15 days or 15 months is irrelevant if your property is not the correct moisture level!!! Your boards will just acclimatise to the wrong humidity level and still move! It is much more important to get the moisture level of your room or concrete slab correct before laying the floor, oak always moves so there will always be small gaps.

If the boards are over 175mm, depending upon their thickness, you may want to face nail in addition to secret nailing. The nailing at 45 degrees helps keep each board in position and restricts the lateral movement somewhat, there will be however some vertical movement (cupping) this is where face nailing comes in handy as it helps to reduce this. Screwing is stronger than nailing, pilot drilling is advisable in both cases, buy a large bag of pilots...

Screws should be at least 50mm x 4.5 to 5 Reisser, Spax or Paslode high quality or similar serrated twin thread. Nails should be 50 or 65mm cut brad flooring nails or rose heads. If you hire a portanailer or similar ask if you can get the face nailing attachment. You will need a good punch, Stanley make a really good massive one which saves your knuckles a little, and a decent hammer like my trusty Estwing 21 oz square head framing nailer. If you are screwing into old oak pilot or not you will need a decent drill, either mains or cordless. If cordless you may want to consider an impact driver, they are horrible and noisy but can help save your batteries.

Dwarf walls are not required, firrings (battens and fillets) can be used. 50mm x 50mm minimum or battens and packers if the run off is small.

Battens can be fitted via screw or by epoxy chemical means, chemical is more expensive but much quicker.

If you are fitting an oak floor direct to the concrete (not advised) then you will need to fit a dpm, no matter what dpm you already have as masonry (concrete included) is hydroscopic and it will affect the timber if in direct contact as acting as a larger moisture sink. If you decide to stick the floor to the concrete then use a compatible liquid dpm / adhesive system, popular systems are available from Bona, Ball and Lecol for example. Using an expensive adhesive that allows a lot of natural movement which resists high sheer forces whilst maintaining a good overall mechanical bond like Bona R850 is good practice in old properties with large humidity changes.

Laying any oak floor as a floating floor is not a good idea in my experience as I have yet in 25 years to see one that hasn't moved, tented, cupped, warped, broken the tongues or generally looked and felt poor and that goes for engineered floors too and I would not advise it.

 

[88v8]

Cut the tongues.............. If the boards are over 175mm, depending upon their thickness, you may want to face nail in addition to secret nailing. The nailing at 45 degrees helps keep each board in position and restricts the lateral movement somewhat, there will be however some vertical movement....

Laying any oak floor as a floating floor is not a good idea in my experience as I have yet in 25 years to see one that hasn't moved, tented, cupped, warped, broken the tongues or generally looked and felt poor

Perhaps I was lucky with mine. There was no movement, other than where water was spilt on it.

I would not cut the tongues unless you find you've been sold a mish-mash and it really will not fit together. If the tongue remains there is no need to face-nail.

Ivor

 

[Toby Newell]

Very lucky I think.

You are correct however. Unless the boards are very wide, well fitted 1 inch thick tongue and grooved boards should not move much.

If you have the patience to swap the boards around to find 'partners' that match then saving the tongues would be ideal.

It's just that after moving from storage which is ordinarily of a higher moisture level to a heated home and after acclimitisation I have found the boards move making fitting tongues difficult.

If the moisture change is small, the acclimatisation gradual and the original floor was laid and fixed well (avoiding building in stresses which are released when lifted from their original property) you may be lucky.

 

[Zebra]

Thank you Toby and Ivor, for your detailed help. I think I shall keep the tongues. Even if they don't fit absolutely tightly, they'll help to prevent a gap appearing if any shrinkage should occur.
Heeding your previous warning, Ivor, about the boards being different widths, thicknesses, and having tongues at different heights, I have gone one better than pre-sorting, I'm afraid, as mine differ slightly too. I'm measuring each one as I clean and treat them, and making a spreadsheet! Then when I need a board that's say 65mm wide, with 10mm above the tongue, and 1200mm long, I can search through the computer and select board number 258!
But I see that perhaps I shall have to get the radiators & boiler installed and working before I lay the floor!! Oh Gawd!

 

[Me!]

Personally I've stopped using the foam pipe insulation in places like lofts and floor voids as I've had it completely eaten off hot pipes by mice a couple of times recently. I now use foil covered rockwool which seems much more rodent proof. The company in the link are in Germany so their initial postage charge per delivery is very high, but their price per length of insulation is a fraction of the best price I can find in England, so as long as I buy a decent quantity it still works out at a very good price.

 

[Zebra]

Thanks me! I'll get some.

 

[LadyArowana]

Thank you Toby and Ivor, for your detailed help. I think I shall keep the tongues. Even if they don't fit absolutely tightly, they'll help to prevent a gap appearing if any shrinkage should occur.
Heeding your previous warning, Ivor, about the boards being different widths, thicknesses, and having tongues at different heights, I have gone one better than pre-sorting, I'm afraid, as mine differ slightly too. I'm measuring each one as I clean and treat them, and making a spreadsheet! Then when I need a board that's say 65mm wide, with 10mm above the tongue, and 1200mm long, I can search through the computer and select board number 258!
But I see that perhaps I shall have to get the radiators & boiler installed and working before I lay the floor!! Oh Gawd!

Remember to backup or printout hard copy, wooden boards are very reliable at doing what they do, computers not so much :lol:

 

[MatthewC]

Thank you Toby and Ivor, for your detailed help. I think I shall keep the tongues. Even if they don't fit absolutely tightly, they'll help to prevent a gap appearing if any shrinkage should occur.
Heeding your previous warning, Ivor, about the boards being different widths, thicknesses, and having tongues at different heights, I have gone one better than pre-sorting, I'm afraid, as mine differ slightly too. I'm measuring each one as I clean and treat them, and making a spreadsheet! Then when I need a board that's say 65mm wide, with 10mm above the tongue, and 1200mm long, I can search through the computer and select board number 258!
But I see that perhaps I shall have to get the radiators & boiler installed and working before I lay the floor!!

You have 258 boards?!!

NB The thing about expansion and shrinkage is to do with moisture which causes expansion; heat reduces moisture and so causes shrinkage. Obvious really, when you think about it (which I hadn't previously).

 

[Zebra]

Yes, they're only very skinny, about 60 - 70mm wide, so to do 30 sq m I'm going to need about 500 linear metres. As they vary in length between 300mm to about 1.5m, that's hundreds of boards.
Never choose the easy way to do things, never!
I don't suppose the house is any damper now then it will be when I have heating. I have a dpc and a dpm now, so dry walls and floor, so perhaps they won't shrink?....

 

[88v8]

Yes, they're only very skinny, about 60 - 70mm wide, so to do 30 sq m I'm going to need about 500 linear metres. As they vary in length between 300mm to about 1.5m, that's hundreds of boards.
Never choose the easy way to do things, never!
I don't suppose the house is any damper now then it will be when I have heating. I have a dpc and a dpm now, so dry walls and floor, so perhaps they won't shrink?....

<3" wide... hmmm. Well,1" thick and 3" wide, you shouldn't have any trouble with cupping. I think once they're down they're down.
Hope they've been stored flat, and not got themselves twisted or bowed sideways.

What's the rh where they are now, and where you're laying them?
If you put one of these on the floor for a while...
http://www.ebay.co.uk/itm/Digital-Thermometer-Humidity-Meter-Kitchen-Room-CarTemperature-Indoor-Hygrometer-/350697841426

With heating pipes in an unventilated space beneath them, even well insulated heating pipes plus an ally heat spreader, I suspect they will shrink. The more you can dry them before laying the better.

Ivor

 

[Toby Newell]

Aha!

Bless you Zebra!

That is not a board, that is a block! Block floor, you can stick that direct to the concrete over a liquid dpm. Edit bless myself! tiredness getting the best of me. Strip floor! That is the correct terminology Zeb, you should have no problems sticking it.

Still think you will have problems matching up the tongues and grooves.

You can use something like Bona R580 dpm then fix your blocks with Bona R850 silane based adhesive, I am using it today in fact, expensive but very good stuff, allows for movement, great for reclaimed floors and older properties, or you can secret nail onto battens.

Toby

 

[Zebra]

I'm starting to lay the timber battens on the concrete floor, level them up and screw them down, as per middi's instructions, ready for laying the floorboards. There, how long did that take? Almost three months, good going!

 

[Toby Newell]

For a strip floor, gluing may be easier direct to the concrete over a liquid dim.

Anyway, best of luck.

T

 

[Zebra]

Thanks Toby, but as I stated in my original post, I can't do that because then where would I put the central heating pipes.
And anyway I have a dpm already, under the concrete.

 

[Toby Newell]

Of course XD sorry, my mistake.

I would still apply a liquid dpm to the concrete surface as the surface is hydroscopic! and will hold more moisture than the surrounding air.

Hire a portanailer, they are very good. You can epoxy the batters to the concrete, but this is quite a bit more expensive than screwing (although maybe easier)

 

[middi]

If your central heating pipes, wires or subsequent services need to be under the floorboards, I still maintain that fixing with screws countersank at 45 % through the tongue is the best option. In case of pipe leaks or any other reason why you need access to below boards the screws are easily removed, the board "squeezed" away from the adjoining board tongue and lifted out without the risk of much damage. the process is repeated for every board until the problem area is reached. The boards can then be refitted with the same screws , and if you are lucky, in the same holes.
It has to appreciated that where fully carpeted floors are desired, softwood or manufactured boards are used and these are fixed in the fastest way possible as the fixings points will not be visible, also if one damaged one of these boards in case it needs to be removed there is not much hardship if it gets a bit damaged, usually, it can be refitted or easily replaced.
Unfortunately where exposed ( and more expensive !!) floorboard are used the fixing has to be a little more " tedious" to allow for removal and " good looks".

Middi

 

[Toby Newell]

:/

countersinking screws into the tongue of strip oak?

:/

sounds quite splitty.

Pipes, in general do not leak.

If there is an important junction or valve that cannot be moved then making a nice access panel is the proper way to go.

Screw heads are too large and are liable to split the coarse grain of the hard oak when driven below the surface, that is why serrated nails are used.

Also.

Serrated nails are designed to allow the oak to move slightly which will help evenly distribute any localised dimensional stresses for example where there are heated pipes underneath (which will contract as they expire moisture compared to adjacent boards that will remain expanded)

Screws are a much firmer fixing and are not designed to be used through the tongue in this way.

Just saying