11mm or 18mm OSB for temporary floating floor.

[epsilonGreedy]

Further to my other thread seeking advice on screeding a small section of floor (11 m2) ahead of the main house floor screeding I am now following @Mr Punter's suggestion to create a temporary floating floor capped with wooden sheet.

 

The width of the floor space is a round 2.4m which is convenient so I am looking at 1 x 3.3 sheets of wood (OSB or Ply) sitting over 100mm thick expanded polystyrene insulation sheet. I will probably  batten around the periphery of the floor to shop the sheets shuffling around and back in the old thread @PeterWsuggested joining the sheets with thin offcuts..

 

Given this outline design what material should I choose OSB or Ply and 11 or 18mm? The floor might have to deal with 18 months a regular foot traffic as the primary house entrance.

 

[Mr Punter]

I would use flooring grade T&G chipboard 18mm.  The sheets glue together with pva and are 0.6m x 2.4m (1.44m2)

 

Best to lay some thin polythene over the insulation first so it does not abrade.

[MortarThePoint]

Will you have an opportunity to reuse the OSB later on? For example flooring in an attic space. If so bear that use in mind and I suspect the 11mm may fall short of what you'd need for the other use.

[ProDave]

I used 13mm OSB as a temporary floor.  Not so bad downstairs (400mm joist centres) but upstairs (600mm joist centres) it was a bit springy, but nobody fell through it.

 

It all got re used, mostly cut into strips that laid in the bottom of the I joists to support the insulation, and as the first layer over the joists to support the UFH biscuit mix.

[epsilonGreedy]

Thanks both, I am coming around to @Temp's suggestion of using floor grade tongue & groove chipboard. I have 2 sheets left over from the first floor decking, I think it is caber deck (the board with a grey laminate textured surface). This will cost a few more £££ than OSB but as this will need to cope with 1st and 2nd fix foot traffic for many months it feels worthwhile.