How to install inline ducted extraction fan?

[joshy1]

Hi.

My roof was leaking and it has been fully replaced. This time the roof has sarking when before it had no sarking.

The old bathroom fan just vented into the roof space and as it had no sarking there was a breeze in the roof so steam could vent out all the gaps in the concrete tile

Now the roof is more air tight as i have waterproof membrane installed. I was looking at a way to use a ducted fan to get the steamy air from the shower vented to the outside via the eves of the house.

Its a small bathroom so i was looking at this fan to do the job for a reasonable cost.

https://www.bunnings.com.au/ixl-170mm-ventair-easy-duct_p4449333

My question is, The instructions call for hanging the fan from the truss's via what it calls "strapping"

It doesn't say what strapping to use or how to fix it to the truss's

Here is a picture from the instructions

thanks for any help, joshy

[EricL]

Hello @joshy1 

Just a friendly reminder that any electrical works must be carried out by a licensed electrician for safety and compliance.

I believe its referring to this type of strap - Airco 30 x 1.0mm x 6m Structural Galvanised Strapping. 

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

[Nailbag]

Hi @joshy1 

The strapping @EricL linked is correct. You would fix it to the trusses with wood screws. Don't be too critical about height and how straight or level it is. The idea is it’s suspended to prevent vibration through the ceiling. 

You shouldn’t need to do any electrical work as the new fan will plug into to the old socket unless that was removed. In which case a sparky will need to put a new one in. If the fan cord is too short for the current socket just use the shortest white (internal) extension lead. 

Nailbag

[joshy1]

yes there is a socket it just plugs into. Does the ducting need to also be elevated ? or is it ok if it sits on top of the insulation ?

[JacobZ]

Hi @joshy1,

The ducting should also be elevated, as any contact with other surfaces can cause thermal transfer, which will result in moisture.

Let me know if you have any further questions.

Jacob

[Dave-1]

Good morning @joshy1 

@EricL and @Nailbag have both suggested the same type of strapping that I would The duct itself can stay resting across the trusses/ceiling. The fan just needsto be off the ceiling so there is no noise/movement transfered through to the actual ceiling and the room below.

Dave

[AlanM52]

Hi @joshy1,

I would use a luggage strap.

https://www.bunnings.com.au/search/products?page=1&q=luggage+straps&sort=BoostOrder

Cordless drill.

Scissors.

Panhead screws.

Cut off a length of strap.

Loop around and with one hand hold against the truss.

With the other hand adjust the height and hold that position - let go.

Add a bit more so you can fold over each end- cut off.

When mounting fold over the ends, bundle together and secure with a couple of panhead screws.

Cheers