Extraction fan query?

[lastbuilders]

Hi All,

In the kitchen of my self build I am having an island with a hob and extraction. We have not bought the extraction fan but are doing the slabbing in the next few weeks. I have run ducting from above the island to the outside terminating in a slate vent. The ducting is 4 inches in diameter. My query is how do I finish this so the extraction fan can be attached later after the slabbing is complete? Do I leave a space with no slabbing done so supports for the fan etc can be attached to joices later?

Lastbuilders

 

[Carpenter]

I would put in good timber grounds at the back of the plasterboard in the immediate location of you extractor. Ply would make a good grounds, saw out a 4 1/2" hole to allow your hose to drop down, fix the ply so that it's lower surface is level with the underside of your ceiling joists (with sw battens fixed to sides of joists to allow ply to be fixed in position). Your plasterboard slabs can now be fixed over the ply (cut out hole for hose to hang down) and installing the extract unit should be easy as you'll have a sound plywood ground behind the ceiling for fixing. Easy!