Ply lining a floor. 6mm x two sheets or 1 x 12mm

[Restoration man]

I am putting down safety flooring in a bathroom. The original floor is 3in wide tandg floor boards. House is 100 year old.

I was planning to ply sheet so the lines don't over time show through the flooring. The safety flooring manufacturer agreed with this and advised 6mm ply.

You obviously lay the ply perpendicular to the original floor but there will also be lines between the ply sheet joins.

Would it be worthwhile laying 6mm ply perpendicular to the original floor and then a second layer perpendicular or 45deg to the first layer?

Also I've read two schools of thought on butting the sheets. 1 says butt them together. Other says leave an expansion gap and silicone the gap?

Cheers guys.

 

[dazlight]

Butt together then feather finish screed the joints.

 

[Restoration man]

What's your thoughts on double sheeting with 6mm laid perpendicular

Vs

Single sheet of 12mm

Cheers

 

[dazlight]

I never had mate. If floor is a bit unlevel we use 9mm plywood.
Just ring nail the plywood down every 6” and 4” on joints.

 

[Doggit]

No point in doing 2 layers, as you'll still get the same effect on the top one. Good tips from Dazlight, but make sure the floor is secure and solid before you start nailing.

 

[Restoration man]

Thanks guys

 

[Restoration man]

Another thought I've had is using modern chip board flooring 8 x 2 sheets which are tongue and grooved.

This way I would be able to butt these up tight glued and screwed and there would be no issues with lines showing through the safety flooring over time?