Gas flue in catio

QrizB

Thanks for the photos - I must admit I'd assumed the flue was above the catio roof, not below it!

I agree with the poster above: a hole in the roof and a plume kit would seem a likely solution.

cathymaker

WIAWSNB said:

Well done - and good photos. 

I never realised a catio could be such a beautiful addition to a home. cough

There is a bargeboard immediately above the poly roof, and a plume flue bracket could almost certainly be attached easily to that. Only the shortest of flues would be needed. The awkward bit is getting access to it!

A nice clearance hole through your roof to take the pipe - it's only 3" dia - with a flexible rubber gasket to prevent rain coming through.

Could a crawl board be paced along that roof, supported at each end by the timber frame? I guess it must be possible, as how else did they secure these roof panels down?

Or, perhaps the builder of that amazing construction could remove the required roof panel, allow the flue pipe to be fitted, and then replace it with a suitably-size U-slot cut. It obviously mustn't make contact with the pipe, and you'd have to clear this option with the GS first.

I see you're jealous of my catio 😅 The catio installer want me to pay them for the privilege of rectifying the mess they've got me into so I won't be going back to them. But thank you ever so much for your advice. I shall speak to my gas engineer and my niece, who seems able to build anything, and take it from there. The other solution is, would you like 2 cats? Seriously though, really appreciate your help 😊

FreeBear

A short plume kit going straight up through the roof would work. Fix a piece of timber on top of the roof screwed through the polycarb sheet in to the horizontal timber closest to the wall. The plume kit can then be secured to this new bit of timber.

The hole through the polycarb sheet can either be a U shaped slot, or a ~75mm round hole. Debatable if you really need any flashing around the hole - Depends on how much water you can tolerate coming through. Only issue I see is clearance between wall & joist. I suspect that you would struggle to get a 90° elbow in, so that length of timber may well need to be moved a few inches.

P.S. Wanna cat - Got one that has developed a taste for warm flesh. Human flesh.

QrizB

FreeBear said:

Debatable if you really need any flashing around the hole - Depends on how much water you can tolerate coming through.

Problem is you'll get water into the hollow parts of the polycarb sheet, then you'll get algae and moss, and before very long you'll have an unplanned in-roof garden. Which will be a pain in the neck to do anything about.

FreeBear said:

P.S. Wanna cat - Got one that has developed a taste for warm flesh. Human flesh.

Remember that people keep dogs, but cats keep people 😉

cathymaker

FreeBear said:

A short plume kit going straight up through the roof would work. Fix a piece of timber on top of the roof screwed through the polycarb sheet in to the horizontal timber closest to the wall. The plume kit can then be secured to this new bit of timber.

The hole through the polycarb sheet can either be a U shaped slot, or a ~75mm round hole. Debatable if you really need any flashing around the hole - Depends on how much water you can tolerate coming through. Only issue I see is clearance between wall & joist. I suspect that you would struggle to get a 90° elbow in, so that length of timber may well need to be moved a few inches.

P.S. Wanna cat - Got one that has developed a taste for warm flesh. Human flesh.

Thank you. That's very helpful as earlier my gas engineer said he'd actually ruled out the plume kit as nothing to attach it to.  I've also thought of just setting the cats free now they've caused me so much hassle so, much as a flesh eating one is tempting 😅  I'd best say no thanks!

Lorian

I am not a gas safe engineer but I'm almost certain you cannot fit a plume management kit and leave the intake below that roof and the exhaust above it.

QrizB

Lorian said:

I am not a gas safe engineer but I'm almost certain you cannot fit a plume management kit and leave the intake below that roof and the exhaust above it.

I'm not one either, see what the OPs fitte .has to say!

Lorian

QrizB said:

Lorian said:

I am not a gas safe engineer but I'm almost certain you cannot fit a plume management kit and leave the intake below that roof and the exhaust above it.

I'm not one either, see what the OPs fitte .has to say!

Indeed.

A little surprised OP hasn't end up with an at-risk notice

FreeBear

Lorian said:

I am not a gas safe engineer but I'm almost certain you cannot fit a plume management kit and leave the intake below that roof and the exhaust above it.

From the WB document I linked to earlier -

The exhaust terminal [of a plume management kit] can also be routed through the roof of the carport providing 25mm clearance is provided around the flue pipe to any flammable material and that it extends at least 300mm above the roof.

If the exhaust terminates within the footprint of the carport then the carport must have at least two sides completely open.

Looking at the images, the exhaust terminal is too close to the polycarb roof (min 75mm clearance) and the window (1200mm min).

WIAWSNB

FreeBear said

From the WB document I linked to earlier -

The exhaust terminal [of a plume management kit] can also be routed through the roof of the carport providing 25mm clearance is provided around the flue pipe to any flammable material and that it extends at least 300mm above the roof.

Thanks for the details.
I'm going to speculate, then, that the GS was effectively saying there was nothing to attach a plume flue to from within the catio. He didn't have - didn't want - the option of getting access to above the roof for this. If he had, then I think the bargeboard would be suitable for mounting a bracket(s).
I'm also going to speculate that, since the catio isn't a permanent construction, any 'plume' solution will have to effectively avoid contact with it. Ie, it cannot be set up so that anyone dismantling the structure - as is bound to occur at some point - could disturb the flue. That part may come down to the judgement of individual GS's, but I wouldn't blame them if they made that call. So, a solution that allows the roof to completely avoid the flue - eg an open-ended cutout with plenty clearance, and no flashing that joins them, is I think more likely to be acceptable.
That would mean a small amount of rain will get through, but I'm guessing that this wouldn't be a problem?
Cathy, can you recall how the builder managed to get access to the roof to attach it down? Were they up on top?