Cooker Hood / Chimney

[phykell]

Hi,

I've read through the various cooker hood threads here on DIYNOT but I'm a bit unclear about what to do about ducting.

The ducting kits are what's really confusing me. I'm going to have my vent passing through the wall rather than through the ceiling. This way I can minimise the amount of effort required to fit it and reduce the length of the ducting. I looked at a kit in B&Q and it was over £25 for a simple wall plate, external duct cover and tube! Screwfix have this one:

http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=12850&id=17489

...and ToolStation have this one:

http://www.toolstation.com/index.html?code=47969

Price difference is unimportant really, but surely I need a duct cover fro the external wall and an internal wall plate for the internal wall (after I've made a mess opening a hole up). It all gets hidden by the chimney of course. The confusing thing is that the Screwfix kit doesn't seem to have an internal wall plate and uses a 1.5m metal hose while the Toolstation one has a 1.0m plastic hose. Neither kit seems to supply the hose between the internal wall plate and the chimney - I assume that the hose just goes from the chimney direct to the external duct cover? Am I better off going for the Screwfix kit as that has the metal hose? Does it make any difference?

 

[fido]

I think the idea is the chimney goes into the ceiling and has a spigot on the end for the hose, which runs in the gap between the ceiling and the floor above. You would remove floorboards above the chosen place to drill the wall and make a pilot hole using a long SDS masonary bit. You then drill the hole bigger from the outside with a core drill. In such cases you would not need an internal wall plate but if you are running the hose somewhere visible you could buy a wall plate. If the gap above the ceiling is restricted you could use the solid rectangular ducting.

 

[phykell]

The installation I was planning has the tube passing through the wall below the ceiling line as the chimney covers it anyway. The installation instructions don't actually specify going through the ceiling but they do show a relatively short run of hose turning 90 deg and through a wall. I suspect there is no minimum length before the bend hence why I can have the hose exit just above the chimney outlet. I'm just confused as I'd expect there to be an external cover and a wall-plate together with enough hose to pass from the chimney outlet to the wallplate and then from the wallplate to the external cover.

 

[fido]

I would suggest you forget the kits and just buy the individual bits to suit what you are planning. It looks like most of the Screwfix stuff is 100mm but if your outlet is 125mm it should still work OK stepped down to 100mm. If 3 metres of hose is too short you could do part of the run with the solid pipe.

 

[Thermo]

Ive done several with there components and they work a treat. Theres quite a bit of play in the joints so youve got room to manouvere before you glue them up. Order more bends etc than you think youll need, as youll need them!