Plywood floor support

[Rollin]

I'm laying a new plywood floor in a kitchen. There is a gap between the brick internal wall and last joist, which is parallel to it, of about 4 inches.
Do I need to support the board at the wall as it's going to be a pain to attach some timber there.
Plywood is going to be either 18mm or 22mm. The unsupported edge is under kitchen cabinets also.

[B'stard Child]

Rollin said:

I'm laying a new plywood floor in a kitchen. There is a gap between the brick internal wall and last joist, which is parallel to it, of about 4 inches.
Do I need to support the board at the wall as it's going to be a pain to attach some timber there.
Plywood is going to be either 18mm or 22mm. The unsupported edge is under kitchen cabinets also.

If I've understood what you are describing - this is normally where the flooring went down before the internal wall went up and you've removed the original floor at the wall edge

Can you not sister a support to the last joist of 4 inches to fill the gap and create the support

[JoshSm]

You don't have to fully support it, just enough to not leave the board hanging.

A bit of 2x4 (or 3x4) alongside glued & screwed through the existing joist in a few places would likely be plenty. Doesn't need to act as a full joist or add load capacity, just provide a bit of extra support for the edge.

It'd likely work without anything extra but if you can why not.

[Rollin]

B'stard Child said:

Rollin said:

I'm laying a new plywood floor in a kitchen. There is a gap between the brick internal wall and last joist, which is parallel to it, of about 4 inches.
Do I need to support the board at the wall as it's going to be a pain to attach some timber there.
Plywood is going to be either 18mm or 22mm. The unsupported edge is under kitchen cabinets also.

If I've understood what you are describing - this is normally where the flooring went down before the internal wall went up and you've removed the original floor at the wall edge

Can you not sister a support to the last joist of 4 inches to fill the gap and create the support

Yes, it's an old house. I removed the knackered floor boards and a rotten joist. The floorboard weren't supported on the edge either

[Chumley.mouse]

Clamp a length of 3/4x2 between the joist and wall , then just screw through into it.

[Rollin]

Thanks all