How Bodged is My Kitchen Extract

[Ivor Windybottom]

I don't really see the point of insulating an extractor duct. It will reduce the condensation but won't eliminate it, so you'll still need a condensate trap anyway. But if you have a trap then there's no need for insulation.

Rigid ducting and a condensate trap would be my preference. I managed to sneak my outlet pipe through the fascia into the gutter, but if it drips onto the ground that's probably not a big deal.

This the one I've used, works well...

Extractor Fan Condensation Trap With Overflow

Fit this Verplas extractor fan condensation trap into the ducting on the exit side of an extractor fan to capture any moisture running down the inside of the duct. It’s just the thing to prevent water caused by condensation collecting and causing a dripping fan or damp patches in the ceiling.The...

www.toolstation.com

It needs to be as close as possible to the top of the ceiling, while having enough height for the liquid to run somewhere under gravity. May need a little compromise. Uses standard dirt cheap 22mm toilet overflow pipe. The short length of duct below it would normally be surrounded by loft insulation anyway, so no need for insulated ducting.

Obviously you shouldn't have any low spots, as the current botch job has. That will gradually fill with water with nowhere to go. All ducting needs to flow into the trap.

 

[AkiraDIY]

Jubilee clips are rubbish on rectangular ducting.

My duct is circular so it's neither here nor there. The regs say "jubilee clip or similar" so it's your choice what mechanical fixing to use. The regs specifically state tape alone isn't the way to do it. So the strength, durability, brand, type of tape, etc is irrelevant. The regs are to be followed. They're not optional based on how lazy/incompetent the builder is, what materials they have on hand that day, or how much they believe they know better than the regs.

Don't let principles get in the way. Anyone who does the sort of job you've got shouldn't be allowed back through your door.

Live and learn, move on and find someone else who can do the job, or DIY.

If it's principles alone, I'd tell them to do one and never come back. Legally, I can't just withhold payment. I believe I have to give them a chance to fix their errors first. If it were that easy avoid paying, no trades person would get paid. Ideally, I'd just get them to clear the rubbish and I'll pay for materials cause the time spent isn't even worth a coffee.

Two 45 degree elbows, a condensate drain, and 2m of straight UPVC is all that's needed to finish it properly. Plus finding a suitable drain point. The eaves of my roof are very tight to the wall, pretty sure I can't sneak a drain past it. Think my best bet is to have it drop into my utility cupboard and tie it into the drain there. Relatively short run (5m total maybe) and can be kept out of sight.

 

[Ivor Windybottom]

Ah OK, I was assuming you'd already paid. Yes, give them a chance to rectify before telling them to do one I suppose. Although the chances of them doing it properly are pretty slim, if anyone thought that effort was acceptable then they obviously don't have a clue.

Hopefully if you tell them it's all substandard, building regulations etc then the end result will be that you'll never hear from them again. Then you can start again.