Best install method for Oak Floorboards

[PrinceCharles]

Chaps,

There seems to be a number of methods to fix new Oak flooring over existing boards, I am hoping that someone can clarify what would be best in my circumstances.

Room size - 4m x 4m
New boards are Solid Oak, Oiled, 120mm x 18mm, lengths 400mm to 1500mm.( existing boards are 150mm wide ).
New boards are to laid over existing 1930's boards which are all sound.
Existing floor is suspended with 12" gap between bottom of boards and blinding concrete. All air bricks are clear and subfloor ventilation is good.
I intend to lay new boards in line with existing rather than at 90deg. due to prevailing light from main window

Should I secret nail, screw ( ELKA Tri-Lock ) or glue?
Should I use a vapour barrier or underlayment?
If glued using an underlayment do I glue boards to the underlayment as well as the tongue & groove?

Thanks

HRH

 

[WoodYouLike]

Have look at one of our manuals in regards of installing a solid floor like you bought.
If you don't plan to install at 90 degrees of the existing boards you do need to overboard thirst

 

[PrinceCharles]

Thanks for the link, Wouldyoulike, a very handy resource. One thing that I can't quite understand though is that if you secret nail floorboards surely the boards are then fixed in position and can't then move due to expansion or contraction. What use would the expansion gaps around the edges be?

Also, is it true to say that boards will expand more across their width rather than along the grain?

Thanks

HRH

 

[WoodYouLike]

Wood works, no matter which method you use. So leave that expansion gap to prevent problems in the long run.

And yes, wood stops 'growing' once it is turned into a board It will expand in the width, hardly ever length ways

 

[PrinceCharles]

After much reading and research I have decided the on the following approach:


Lay a vapour barrier - I don't think it's 100% necessary but I'll do it anyway.
New 18mm Oak boards will be laid at 90deg to existing boards
New boards will be PVA glued along full length and width of grooves.
16mm expansion gaps all round
No secret nailing.

Does this sound acceptable or am I missing something really important??

Thanks

HRH

 

[WoodYouLike]

After much reading and research I have decided the on the following approach:

Lay a vapour barrier - I don't think it's 100% necessary but I'll do it anyway.

Does this sound acceptable or am I missing something really important??

Thanks

Don't put a vapour barrier on your existing floorboards! It's 100% guaranteed to cause problems later on with condensation - moist getting to your existing floorboards and even rotting of joists.

Use a foam underlayment without DPM, then install your new boards the way you described.

 

[salska]

I did my floors a couple of years ago. Nailed directly onto chipboard floors. The boards were a softer hardwood variety.

No vapour barrier used. Removed and trimmed all skirts once the boards were layed and left expansion around edges. No glue used. Results were amazing and no problems to date.

I did however leave the boxed boards in the house for 2 days to aclimatise prior to knocking em in. I should really have invested in a nail gun. But they are quite expensive and I wasn't sure if it would work so I just did it manually with a hammer and centre punch!!!!

Patience required. Have fun.