[Closed] Installing solid oak floor, do I need anything under it?

email trout off here.
he does it for a job.

I was hoping DD would chip in too...

What would be the purpose of the layer underneath? I'm no expert but I believe that an underlay of some sort is required as either a vapour barrier or to act as a thermal insulation. As neither of these will be applicable to an upstairs bedroom I wouldn't bother. Only other thing I can think of is something to act as an insulator of noise.

Only other thing I can think of is something to act as an insulator of noise.

Thats what I was thinking too. Most of the underlays seem to be for floating floors or self adhesive so you don't need glue but I don't want either. I've found a couple of websites that say you need an underlay with a nailer solid wood floor but they don't elaborate with what exactly you should buy. Noise transferring from one room to another isn't really a problem as it won't be used as a bedroom.

Probably not a bad idea to run a layer of builder’s paper underneath if you can get some. It’s hard work to get hold of these days. It’s two layers of thick brown paper with a layer of something like bitumen sandwiched between. Although, as it’s an upstairs room, I wouldn’t bother. Don’t use underlay of any kind - you’ll end up with a squeaky floor.

If it were me, I’d stick more to tongue-tites rather than nails - unless you’re pushed for time. Again, with a solid floor, over existing floorboards, you’re going to get the odd void here and there, which could lead to squeaks. Pre-drill your boards, otherwise the tts will split the oak. I think tts are 3.5mm, so buy yourself a little box of 2.5 or 3mm bits as you’ll no doubt snap one or two while doing it.

Any cupping of the boards will be due to relative humidity in the room. Being a first floor, there shouldn’t be any moisture coming from underneath.

Actually thinking about it, if you wanted something to help with noise, then lay with liquid batons - sausages of adhesive applied with a bulk gun. Then use tongue-tites every few rows (depending on width of boards) to pull it all together nice and tightly. Apply glue to every third board-ish (ie the boards underneath).

My understanding is to use a waxed paper underlayment with nail down to prevent floor squeeks between the subfloor and your oak.
Waxed builders paper that is.

Thanks DD. I have found it hard to find the builders paper so glad I don't have to use it!

Do you really have to predrill the boards? I was hoping I wouldn't have to but its not a large room so its not too onerous.

I already have the Portanailer and nails but if you think I don't need them I may sell them on, bought the nailer on ebay for a decent price and they seem to sell well.

I would pre-drill, yes. The tongue-tites will split the tongue away in solid oak. Well, they will and then sometimes they won’t. But best practice is to pre-drill when going into solid hardwood.

Personally, I’d go liquid batons and tongue-tites Although portnailing shouldn’t be a problem unless floor underneath is uneven (even slightly).

The floor is a bit uneven (old floorboards but I don’t have the height to underboard) so yes so I’ll stick with the screws.

Thanks very much for the help.

http://www.vanillawoodfloors.co.uk/products/798-bona-r850t-adhesive-sausage-20-x-600ml.aspx

Something like this for liquid batons. You could prob find it cheaper but this + gun is what you need. Generally 1ish tube will do 2ish sqm.

Personally I would use the Portanailer straight onto the boards as it pulls the boards together as you knock the nail in which screws don't always do. The first and last few rows can benefit from hand nailing the tongue using a 3.5mm pilot hole, sinking the nails home with a punch.

Something like this for liquid batons. You could prob find it cheaper but this + gun is what you need. Generally 1ish tube will do 2ish sqm.

Crikey that’s expensive stuff. I’m only doing about 6m2.

Thanks for the help DD

Plenty of places will sell it by the tube. (Search Bona R850T or Sika T52 Sausage.) Pretty sure tookstation do a cheapo bulk gun. And you’re welcome! 🙂

Btw, chickenman does make a good point - the portnailer can be useful to pull the floor together, but the tongue-rites should do it also as long as you’ve got a reasonably good angle on them ie shallower than 45 deg. If you are using the nailer, make sure you’ve got it set at an angle so that the nails don’t protrude through your floor boards, 2” nails at 45deg thru 18mm flooring probably will. There’s an angled shoe that fits on to send the nails through at 40ish degrees - either have one of those or use 1.5” nails.

I bought 38mm nails as I only have the shoe it came with - the extra shoes are very very expensive - as I bought it off eBay 2nd hand.

Good work!

DD - how do you apply that liquid baton? I can’t find how you use it. I didn’t think you could glue down solid wood floor onto floorboards I don’t really get how it works.

Click on

I can’t post the image.

I drew a diagram which I was trying to post which looks exactly like that! Thanks.

I am assuming that is you they took a picture of. 😀

Yeah that. Except better looking and shorter. 🙂

Sorry to be a real pain but I've looked at the instructions for that glue and it says it needs to be trowelled out (notched trowel) which I don't think is what you were saying. I can't see how if its just a glue that it'll do anything but stick the floor down and if thats all it does then why not just screw it down all the way?

Sorry if I'm being a dimwit.

Time to lay it isn't a problem, but cost is.