flexible ducting for heating and cooling?

[Spar]

I am putting in a basement bathroom and need to run venting for the ceiling exhaust fan.

I need to run the exhuasting duct perpendicular to the 8" Joists to the exterior wall. However, there is currently an 8-foot run of 5-inch round duct there running directly centre of the joints (running from a top takeoff from the main trunk duct to a floor register above).

This does not leave enough room for the fan housing nor the exhaust ducts.

Question: does Ontario code allow me to use some kind of flexible duct for the heating and cooling vents? That way I could splice flexible ducting to go around fan housing and then beside the exhaust duct? (I'm using low profile fan with ceiling dropped down 1.5 once below studs, so there would be room over it). If so, what is it? I can only find flexible ducts that say they are for dryers or bathroom exhaust

[Admin]

Look at the Thermaflex Pro Series Non-Insulated ST-L product.  Flexible duct will restrict airflow so if airflow is an issue buy a 6" flexible duct and use a 5" x 6" reducer to connect it to the existing 5" rigid duct.  It's good practice to increase the flex one size above the rigid duct size when used.

https://thermaflex.net/products/thermaflex-s-tl-flexible-duct/

[Porcupinepuffer]

Is there no way to do some offsets with some 5" elbows to move the duct over a bit? The easiest product to work with is the stuff the admin listed. If that's not easily available, you could get some flexible aluminum that you stretch out and bend to what you want. It stays solid once bent into position and isn't like the flimsy slinky dryer vent stuff.

[Spar]

Thanks to both!

I can't reach either of the takeoffs to put in some elbows.

If I can't find what admin mentions is this what you're referring to:

https://www.rona.ca/en/product/5-x-25-flexible-aps-duct-1224577

And there's no issues with flexible permanent ducting? I've worked in so many homes and have never seen it....but maybe I wasn't looking

[Porcupinepuffer]

The stuff I'm talking about is more like this https://www.boone.ca/en/products/hvac/ductwork/5-x-10-aluminum-flex-pipe-non-insulated/?keywords=aluminum+flex

I believe boone does sell to the general public and you don't need to be a contractor.

But as admin suggests, if it might cause too much of a reduction in airflow you can get a 6-5 adapter or two and increase the flex one size up to be on the safe side for that run. The corrugation in flex does cause less airflow for obvious reasons. There's also more restriction if there's a decent amount of bends from twists and turns.