Boxing in a 6" dia outlet

[Nthkentman]

The final phase (Albeit 3 months later than planned) of completing the kitchen refit I need to box in the outlet for the cooker hood. Said hose is one of the expandable convoluted aluminium type stretched to suit the distance between the walls. The hood chucks through 720 cu/ft a min when full on hence the diameter required.

From one side across to the other side outer wall it disappears through a through a nice outlet and the entire shebang is clipped to the adjacent wall. Span is only 77".

2 x 2 is already in place as a framework on wall and ceiling, and I'll probably add whatever reinforcing where required, so my question is

1) Plasterboard and paint over. 3/8ths?

2) Plywood and paint over. 1/8th ? or 3) What?

Opinions?

[newshound]

Personally I would use plywood (or MDF, if I had that to hand) but probably 9 or 12 mm: easier to work and fit, more rigid so should not vibrate and will look nicer. With 6 mm you need a batten on the inside and probably a moulding on the outside to make it look tidy.

You *do* already have a sawboard, I trust? If not, see wiki.

[fred]

In article , Nthkentman writes

The ply will be easier as the long edges wont need extra finishing (as long as you put a small lap on the horizontal to cover the sides).

[Nthkentman]

Personally I would use plywood (or MDF, if I had that to hand) but probably 9 or 12 mm: easier to work and fit, more rigid so should not vibrate and will look nicer. With 6 mm you need a batten on the inside and probably a moulding on the outside to make it look tidy.

You *do* already have a sawboard, I trust? If not, see wiki.

Nope.... But the local "Shed" I am V V friendly with has a lovely wall mounted saw unit..... Amazing what a bottle of wine will help with

[newshound]

Well, that's OK if you have flat walls. Mine are wavy, so often the first job is to scribe and cut an oversized board to fit the wall, then you markup the other (outside) edge at each end where you want it to be, then cut with the sawboard. That lets you construct square structures which fit into irregular spaces.

But really, for speed of accurate construction of stuff out of sheet I cannot recommend a sawboard too highly.