Conservatory floor joist advice

[ipbr21054]

Hi,
I need to take up our floor joists as some i can put my finger through due to a water leak of which has know been fixed from the conservatory windows.

The new joists are 6 x 2 x 4.2mtr but my question is can i use 18mm OSB ontop then followed by lamiante flooring.
I have phoned around to see if there was say 22mm but dont seem to have any luck & most people can only supply 18mm OSB.

Can advise if 18mm is suitable.

Thanks

 

[^woody^]

Osb is crap as a floor deck.

An 18mm deck of other boards would need joists at no more than 400 centres

 

[ipbr21054]

Thanks,
I have ordered 22mm boards & joists are 400 apart

 

[Leofric]

18 or 22mm tongue and groove flooring grade chipboard. 150 x 50mm softwood joists at 400mm centres are over spanned at 4.2m (unless there is some intermediate support ) 200 x 50mm joists would be at the limit, or even slightly over, spanning 4.2m.

 

[ipbr21054]

Hi,
My mistake, it’s 3.6 Mtr NOT 4.2.
I am replacing what was there so I need to just put new down as no option.

So as this isn’t my field here is info again.
Joists as 6 x 2 x 3.6 mtr.

There is a length on wood fixed to the wall where one end of the hoist sits on & the conservatory end there are pockets in the wall which the joist enters and sits on.

Do I need to put say a length of wood under the joists in the middle to support / help it ?

If so please advise thanks.

 

[oldbutnotdead]

Put noggins or herringbone struts between the joists to stiffen the floor. You can prop on the centreline if you want but you shouldn't need to.

 

[Notch7]

Are you putting in insulation?

 

[ipbr21054]

yes i am to put noggins in.
no to insulation as insulation in walls already

 

[Leofric]

no to insulation as insulation in walls already

walls aren't floor Is this a ventilated suspended timber ground floor If so, honeycomb sleeper walls are usually used to reduce span of joists on these type of floors.

 

[ipbr21054]

Its a conservatory on the ground floor.
Ive put down some DPM i think its called and then put bricks around just to keep it in place.
Yes to ventilated as air bricks on house wall and on conservatory wall.
Floor is say 18 inches from the ground.
The wall on the conservatory wall has pockets for the joists but also say a full brick then half brick then a small gap.this pattern is staggered the length & height of the wall .