Fitting integrated extractor hood to a unit with back panel

[jacoscar]

Can't see the photograph.

You may need to cut away more of the back than you suspect - your upstand is 20mm thick, but the service void is 17mm and the back is 8mm thick (so 25mm). Standard batten is ex-2 x 1in softwood (so 44 x 22mm from many merchants). I'm concerned at how you think you are going to cut out such a large chunk of the bottom of the cabinet and then replace it by such a thin piece of MFC(?). Your sequencing is all wrong - you need to put the strengthening in firstt, I think it will need to be more than 30mm(?) and the bottom shouldn't be cut out before the new front stretcher is fixed in. TBH with a need to accommodate hinge cut-outs and a front cut-out I think you are looking at 125 to 150mm tall for it to be strong enough. I am also left wondereing how you will get that extractor in there, as the cabinet plus doors is 320mm deep, but you lose 20mm for battens (leaving 300mm to the face of the doors) whilst the manufacturers instructions calls for a service depth of 307mm (which will leave your extractor sticking out 7mm at the front) - see below:

View attachment 268138

Seems to me that having a 20mm thick splashback without taking the extractor into account is a bit of a design error on the grounds that you are trying to fit a quart into a pint pot so to speak. Maybe you need to consider making up timber grounds to pull all the tap cabinets forward by 20mm or so to overcome this issue

BTW, my original drawings weren't intended to be a worked through design, just an idea which shows how such installations are approached. For a fully worked example I charge!

307mm is the depth of the section of the extractor that sits below the unit (where the filters are), the section that goes inside is only 273mm
The bottom is not meant to be flush with the unit

 

[jacoscar]

I made a bit of progress on the installation and I’ve come to realise the two wall screws at the back of the unit might be some kind of safety measure or just to make the installation easier (?) as they tell you to fit them at a certain height, which would result in the extractor not being flat with the bottom of the unit; and if I raise them to a height where they can support it and leave it flush, then it’s impossible to install because you need to hook on to them from the top

 

[Deleted member 174758]

As far as I can recall many of the extractors I've seen (installed) are hung off the back wall - the back wall is often masonry, or at least has a pattress in it, so it will carry the load - or off the ceiling (there were a couple of downdraughts, but they are a different can of worms). There were (recirculatory) units at one time that fixed to the sides of adjacent cabinets, but even they used to call for fixings into the wall behind. Ideally you don't want to support the weight off the units

 

[jacoscar]

As far as I can recall many of the extractors I've seen (installed) are hung off the back wall - the back wall is often masonry, or at least has a pattress in it, so it will carry the load - or off the ceiling (there were a couple of downdraughts, but they are a different can of worms). There were (recirculatory) units at one time that fixed to the sides of adjacent cabinets, but even they used to call for fixings into the wall behind. Ideally you don't want to support the weight off the units

I’ll try to have fixings into the wall, but will probably have to fit the screws after the extractor

 

[jacoscar]

I ended up screwing some timber to the wall and then hanging the extractor with screws onto the timber; the weird thing is that I had to put the extractor in place BEFORE fitting the screws (you cannot lift it up and then drop it because it clashes against the cabinet itself; whoever wrote the instructions must have been high)

Anyway, this is how it looks