cooker hood extractor venting

[craigsparky]

i am venting a cooker hood up through the loft and out the soffit. i have some standard 4" soil pipe and bends. if it fits the hood can i use them or do i need to use special ducting?

 

[scarypants]

I'd be if they did fit usually bigger than that, about 150mm.
but don't see any reason why they can't be used as the last kit I put together had flexy plastic extension for outlet.

 

[ban-all-sheds]

Check with the maker of the hood - too long a run and too many bends might stop it working.

 

[craigsparky]

ok cheers. but as far as the type of ducting? standard soil pipe ok aslong as it fits the hood?

 

[scarypants]

Check with the maker of the hood - too long a run and too many bends might stop it working.

That's a good point why are we not going out through wall?

 

[scarypants]

ok cheers. but as far as the type of ducting? standard soil pipe ok aslong as it fits the hood?

No expert but can't see why not if they use flexible plastic ones!

 

[craigsparky]

good point, cheers mate

 

[ban-all-sheds]

Aside from the fact that scarypants is almost certainly right - 4" won't fit.

 

[galco]

Check diameter of cooker hood outlet - best practice (where possible) is to keep ducting the same size throughout. Soilpipe is usually 110mm. Most powerful cookerhoods these days are usually 125 or 150mm. Using anything smaller and your going to build up resistance and probably create a noisier cooker hood - like: http://www.diynot.com/forums/viewtopic.php?t=179329
For quick guidance on plastic ducting see: http://www.i-sells.co.uk/ducting-plastic - they do the larger sizes in rigid and flexible.
If cooker hood is 100mm then soil pipe not a problem just make sure that join is good