Cooker Hood Extraction into the loft

[Sprogginz]

Hi,

I've already read a few threads about extracting into the loft and can see that it is doable so apologies if this seems repetitive but I'm looking for something a little more specific.

Once I've made the required hole into the loft, can it just be a simple case of squeezing the end of the duct into the open gap at the end of the joists so that it protrudes out slightly?

I know this sounds crude but I'm looking for the simplest option yet works as it should.

There is already a pipe going out of the roof for the bathroom extractor and someone said that I can join it to this but I need things like a back flow vent etc. This sounds a bit precarious especially if both of them are being used at the same time. I don't fancy the possibility of having the smell of fried fish in the bathroom.

Are there legal points to take into consideration such as angles and maximum length (I'd need about 2 metres of duct in the loft)?

Thanks very much and hope you can help.

BTW, my cooker is not on the outside wall otherwise I'd make a hole in the wall.

 

[Burnerman]

Forgive me, but you aren't intending just to vent into the loft void, are you
By all means continue the ducting into the loft, and then to the outside through the roof shell (with appropriate pipe flashing) or through a convenient gable end....its also known to return the duct back through a soffit, but this is less desirable - especially if there is a window near by.
John

 

[Sprogginz]

Thanks for your reply, I really appreciate it.

I'm not intending to vent into the loft void! Basically, I want to somehow have the end of the vent meeting the outside without having to make a hole anywhere or with minimum alterations. I know you might be thinking why I can't just do it properly but at the moment I can't or shouldn't make any alterations to the outside structure. I would like to have it vented out of the roof shell eventually but for now, the simpler the better.

The vent would be between 2 windows that are about 2 metres apart. Would that be enough?

Thanks very much.

 

[Burnerman]

So whats your plan now then......you've got the extractor pipe up into the loft, but are you heading down and out through the soffit - or through a wall?
Either way, solid ducting is better than flexible, and if there is likely to be any moisture in the pipe, keep the pipe steadily going down hill to the vent.
John

 

[rjm2k]

Thanks for your reply, I really appreciate it.

I'm not intending to vent into the loft void! Basically, I want to somehow have the end of the vent meeting the outside without having to make a hole anywhere or with minimum alterations. I know you might be thinking why I can't just do it properly but at the moment I can't or shouldn't make any alterations to the outside structure. I would like to have it vented out of the roof shell eventually but for now, the simpler the better.

The vent would be between 2 windows that are about 2 metres apart. Would that be enough?

Thanks very much.

In the loft space you have 3 options,

1 take the pipe out of the soffit (after making a hole in the soffit and fitting an external grill for the vent)

2. take the pipe out of a gable end wall (after making a hole in the wall and fitting an external grill for the vent)

3. take the pipe out of a vent tile (after replacing a normal tile with an appropriate vent tile)

 

[Sprogginz]

Thanks again for the advice, I'm hoping my plan is viable now

So my plan now would be to attach, as suggested, a hard vent to the vent coming out of the kitchen ceiling using a 90 degree bend where it's slightly raised off the loft floor so the hard vent will run with a slight decline to the soffit.

From there is it possible to attach some kind of end-vent that is smaller than the hard vent so that it will fit through the soffit?

Hope that's clear and viable. Thanks again.

 

[Sprogginz]

...In the loft space you have 3 options,

1 take the pipe out of the soffit (after making a hole in the soffit and fitting an external grill for the vent)

2. take the pipe out of a gable end wall (after making a hole in the wall and fitting an external grill for the vent)

3. take the pipe out of a vent tile (after replacing a normal tile with an appropriate vent tile)

Sorry, I had already posted a reply before seeing your post.

Option 1 seems to be the easiest. It's the one I'm planning especially because it leaves room for any screw-ups by yours truly.

I'll crawl up to the soffit soon to see just how the vent will fit so I have a better understanding of exactly how it reaches the outside and where exactly to fit any grille if I have to.

Thank you.

 

[Sprogginz]

After crawling around in the loft and hanging out my kitchen window on the 2nd floor, I think there's no room to fit a vent out of the soffit since there isn't really one!

Does anyone know how much it would cost for a tradesman just to simply install a vent out of the roof tiles?

There are two other options which is to have a suspended galvanised duct across the kitchen ceiling (might look nice) and out through the existing wall extractor [after removing that, it's rubbish anyway) or joining the duct to the existing one in the loft [See photo] which goes through the roof. This duct seems to be for the bathroom extractor fan and possibly not just for my bathroom but the flat below too. Is it viable and simply a matter of cutting and joining into it or do I need to other stuff like a condensation trap?

Here is a photo of it:

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• Sprogginz
• 1 Aug 2013
• 1