Cooker hood vent through flat roof

[filipe]

Hi all,

I'm installing a cooker hood in the kitchen that can only output via the kitchen's flat roof.
The flat roof is made of tar an gravel.

The question is, can I use this kit? Is asphalt compatible with tar and gravel roofs?
https://www.roofingsuperstore.co.uk/product/oft-1a110-flat-roof-ventterminal.html

Note: I'm not going to install the vent myself, I'm going to contract someone. I just want to get all the material ready.

Thanks,
-Filipe

 

[ree]

Punching a hole in a flat roof is a fraught business that was traditionally done by experienced flat roofers using heat.

Besides the roof surface there is the matter of what kind of flat roof you have and how, or even if, its insulated.

Done improperly, you could be introducing condensation difficulties into the roof or, at worst, leaks.

 

[bernardgreen]

Used this method for a flue through a flat roof. Never had any leaks or problems with it.

 

[ree]

bernardgreen,

that sketch wont fly as advice, no "method" is indicated or explained:

1. What do the upstands refer to? As far as i can see you show the roof structure as an upstand, and the felt cover as an upstand - how is this achieved?

2. Any kind of felt seal being made on a "tar and gravel roof", or any kind of felt roof, is best done with heat. What does your blue "felt layer" refer to?

3. Is the original roof in the sketch a felt roof or an asphalt roof?

4. Based on the info supplied above its uncertain what kind of roof covering the OP actually has?

5. Without a pic we dont know the condition of the tar and gravel roof or even if the spot chosen for the vent terminal is in a dip/ponding area?

 

[foxhole]

I'm installing a cooker hood in the kitchen that can only output via the kitchen's flat roof.
Why? does the kitchen not have an external wall.?

 

[filipe]

Hi Ree,

Thanks for the info. Like I mentioned in the post I wouldn't do it myself but would contract a professional. My question was more towards the flue material itself.

 

[filipe]

Hi Foxhole,

3 of the walls are against: neighbour, dining room and bathroom.
The only external wall is opposite the cooker and has the lights wiring/box in the way.
I could try to remove the facia board to have a look in terms of room to run the flat pipe. I suspect I would have to remove quite a bit of insulation to make room for the pipe.

Thanks,
Filipe

 

[noseall]

You want a piece of this....

One of these....

One of these.......

A bit of this...

and a little bit of this....

a smidgen of this....

And a competent flat roofer too.