Need correct answer on how to fit a large solid oak floor.

[jimsters]

I have had different advice from different suppliers and seed different methods on here.

Im installing a solid oak floor for a customer.
The room is roughly 8.6m long x 3.6m wide.
They want the flooring to run the length of the room from window to french doors.
The original floorboards also run the length of the room and they want the new flooring to go the same way.

From various suppliers ive been told to:

"secret screw" the boards using a 6mm thick foam underlay and go with the floorboards.
"secret screw or nail" at 90 degrees to floorboards with a dpm installed under it.
"install as floating floor"
"install 6mm wbp ply over floorboard first"


I want a proper answer on how to install this.
Do i ply the floor?
Can i actually go with the floorboards?
Do i need a dpm?
Do i nail it with a floor nailer, secret screw it, or glue it?
How much of an expansion gap is actually needed?
Im putting new skirting over it however MDF skirting is only 18mm thick.

thanks

 

[foxhole]

Usually cross the boards since any undulation in there length will be mirrored if you lay inline.Over-boarding will depend on the state of the current boards, if they are in a very poor state then board over.Timber over timber should not need a dpm.You can secret nail or self adhesive insulation is also an option, gives you a floating floor which will also even out slight undulation and has built in dpm even if not required.Can be a bit tricky to install in confined space or where there are lots of alcoves or doorways.Expansion gap is stipulated by manufacturer around 10mm .

 

[keenedge]

Why not suggest to the customer that they get someone who knows what to do.

 

[jimsters]

I was just wondering if there seems to be a set answer because each supplier suggests a different installation method.
Things should be installed how the suppliers recommend however they all recommend a different method so I thought i would have a look online.

There seems to be a mix of information floating around.

Expansion gap:
10mm is standard, however some say 3mm per m gap, some say 10mm gap upto 3m then 1mm extra per m etc etc.
With a length of 8.6m i can get 18mm from the new skirting and also probably close to 12mm from the plaster on the wall making 30mm. Ill have to allow an overhang for the skirting but i should easy get 20mm+ which seems good enough.

Installation method:
Here is where suppliers seem to differ on their advice.
Just as an example,
National Flooring Supplier 1 (removing name) says to screw through the tongue and to use a DPM over floorboards. No underlay is needed.
National Flooring Supplier 2 (removing name) says to use the fibre underlay mats of 6mm like laminate flooring and you can lay them any way you like.
Supplier 3 says use a floor nailer.

Now i would normally lay them at 90 degrees to the floorboards and fix with a floorboard nailer, however the customer wants them running with the boards and i admit that will look better in the room. I know the customer isnt always right so i thought i would make sure before i do it.

My original idea was to overboard with 6mm minimum wbp ply. Id only do this if the floorboards were in good condition and all fixed properly. This would take out any of the undulations and then the new flooring should sit ok running with the original floorboards. I would have thought using a floor nailer over this would be a good installation method.

Ive come on here to check before i do the job because of the different advice by suppliers.

I see there is also the self adhesive underlay which acts as a floating floor which also sounds ok. Ive never used this before so ill have a read up on it.

Anybody else got a view on going with the floorboards over a length of 8.6m?


Also one last thing.
The installation is the large room and also into a hallway.
The customer is happy using a threshold/doorbar between the room and the hall, however i could go straight through and do it all as one floor without splitting it up. This would look a lot better, BUT should this really be done? The split at the door will allow an extra expansion gap which is probably needed over this large floor, however doing it without will look much better. Should this be avoided?