18mm T&G Chipboard with odd joist spacing

[KillianFrancis]

Hi all.

I’ve resolved my bouncy floor by packing it out so moving on to replacing the old damaged floorboards in preparation for laying laminate.

The joists are spaced anywhere between 250mm to 370mm apart, clearly consistency wasn’t a thing when the builder put this floor together back in the 30s.

I’m wanting to lay (ideally) 18mm tongue and groove chipboard or OBS but I appreciate 22mm will offer a higher degree of stability and reduce any unwanted sound.

I’m trying to minimise the floor raising above the pre existing tiles in the dinning room to create a flush finish not only for the look but also the previous owners installed lovely solid oak bifold doors which open and close the living room off from the rest of the house. If there is a height difference it prevents the doors from closing fully.

So to come to my question.

Given how most of the joists are so close together, will 18mm t&g OBS or chipboard be appropriate or do I need to rethink my approach? (Gaps between joists are listed below)

Left to right joist gap lengths (cm)
5
35
37.9
30.9
31
29.9
33.5
33
26.3
33
27
25
8.5


Thanks!!

 

[endecotp]

I’m wanting to lay (ideally) 18mm tongue and groove chipboard or OBS but I appreciate 22mm will offer a higher degree of stability and reduce any unwanted sound.

My recollection, and this is not something I’ve needed to understand recently, is that 18mm OSB is equivalent to 22mm chipboard in terms of its strength for flooring usage.

 

[KillianFrancis]

My recollection, and this is not something I’ve needed to understand recently, is that 18mm OSB is equivalent to 22mm chipboard in terms of its strength for flooring usage.

So you’d be saying then that the following would be suitable?

Wickes - TG4 Roof & Flooring OBS 3 Sheet - - 18mm 2400mm by 595mm

If so, that was my first port of call

 

[big-all]

to keep it easier to understand everything is talked off in centres for sheet material as in the centre off one joist to another never ever use "between joists" as it serves no actual purpose as boards should be joined on joist or timber centres
the joists at beginning and end off run can be half a joist less so the flooring reaches the edge and this will be planned in but centres still used for all other timbers to get maximum use and minimum waste on sheet material
370 will be 406/16" centres if you look at your tape it will probably have diamonds /dots or triangles at 16"---400mm increments for centres for marking out sheet material centres