Holesaw sizing - pvc ceiling

[Gille]

Feeling a bit thick...

Looking to cut a 100mm hole in pvc bathroom ceiling for extractor vent to the loft and tile vent but unclear on holesaw size. I am presuming the standard 102mm that comes with most holesaw kits will cut a 100mm hole, is this right? I am presuming the holesaw has an external and internal measurement.

 

[rsgaz]

102mm that comes with most holesaw kits will cut a 100mm hole, is this right?

No, they come as 102mm, because that's 4 inches rounded up (101.6mm). It will cut a 102mm hole. Possibly slightly oversize, due to drilling vibration or the drill chuck/arbor not being dead on.

Check the manual for the fan though, my "100mm" extractors need a 110mm hole.

 

[SammyInnit]

Ventilation fittings come in standard diameters. 100mm, 125, 150, 160, 180, 200.

If your fan is (probably will be) 100mm, 102 should be snug around the OD. If it's ceiling mount and you're running a flex off the back of it is go 125 to avoid pinching.

 

[Gille]

Ventilation fittings come in standard diameters. 100mm, 125, 150, 160, 180, 200.

If your fan is (probably will be) 100mm, 102 should be snug around the OD. If it's ceiling mount and you're running a flex off the back of it is go 125 to avoid pinching.

It's an in-line fan in the loft, the hole in pvc ceiling is just for this bezel:

Ae235

• Gille
• 21 Jan 2018

extractor bezel

 

[SammyInnit]

It's an in-line fan in the loft, the hole in pvc ceiling is just for this bezel:

Ae235

• Gille
• 21 Jan 2018

extractor bezel

What's the outer diameter of the spigot side?