Ventilation Ducting through PIR Insulation...

[da3533]

Hello

My bathroom in my loft conversion needs an extractor fan. I will be using a remote inline fan.
See below. the red dot would be where the ventilation grill is. the red line is the 100mm ducting.
However, this can only go between the rafters where the PIR insulation board will be fit..... so do I cut a 100mm tunnel into the back of the insulated board, and use insulated ducting?


Thanks

 

[Swwils]

Why can't you put the vent grill lower?

 

[da3533]

Why can't you put the vent grill lower?

thought the higher it is, the better?

 

[Swwils]

thought the higher it is, the better?

For what reason?

Ideally you want the shortest possible ducting run from your bathroom vent, balanced with simplicity of install through your roof.

 

[da3533]

For what reason?

Ideally you want the shortest possible ducting run from your bathroom vent, balanced with simplicity of install through your roof.

thought the vents not allowed to be lower than 2m. But I guess that’s for non in-line fan…

 

[Swwils]

I am now very confused at what you are doing.

Isn't this just an extraction vent for wet air from the bathroom?

 

[da3533]

I am now very confused at what you are doing.

Isn't this just an extraction vent for wet air from the bathroom?

hi

Yes it is. It’s my bathroom up in my loft conversion. It will be situated above the bathtub. On the UK regs, it says that vent fans must be 2.10m from floor standing .
So I didn’t know I was allowed to put it lower towards the end side of the bath tub as that side is sloppier than the top hence the lower the fan is. I just don’t want the building officer to say it’s wrong and that I have to remove it and relocate it…

 

[cdbe]

You're going the wrong way, go up, out through the ridge! We all think you're on about a fan coming from the floor below!

 

[da3533]

You're going the wrong way, go up, out through the ridge! We all think you're on about a fan coming from the floor below!

my first initial post above states it’s a bathroom in my loft conversion, so the mentioning of an extractor can only relate to that.

I wanted to go through the ridge but not correct as I can’t plant the remote in-line fan on top of the ceiling of a room. The bathroom is in between to rooms

 

[cdbe]

Ok. So you don't have an area of flat ceiling in the apex of the loft with a void above it.

I would use flat channel ducting with a thinner layer of insulation.

 

[da3533]

I have like half a meter…

 

[IT Minion]

I have like half a meter…

View attachment 237437

That should be enough.

The grille should be directly above the shower for best performance, then your fan somewhere near an access hatch and the vent popping out the side of the roof.

 

[da3533]

That should be enough.

The grille should be directly above the shower for best performance, then your fan somewhere near an access hatch and the vent popping out the side of the roof.

hi

thanks

like this:

I will use a IP rated zone 1 extractor instead of inline. Then connect the other end to the roof vent