MVHR 2nd Fix

[richo106]

Good Morning

 

I have first fixed all my MVHR and now have majority of ceilings boarded with the MVHR outlets sticking through.

 

My question is when is the best time to trim them level? After skimming?

 

I have 2 parts left ( see attached pics) and to be honest I’m not sure when/how to install them. If anyone could advise it would be greatly appreciated 

 

 

[jfb]

Presumably the grey bit pushes into the duct and then you screw the cowl on?

check it and see.

plasterers going to be happy if it is cut back so can plaster without restriction

[richo106]

2 hours ago, jfb said:

Presumably the grey bit pushes into the duct and then you screw the cowl on?

check it and see.

plasterers going to be happy if it is cut back so can plaster without restriction

Thank you @jfb I’ll trim my outlets about 3mm below plasterboard level. Then once they have skimmed I’ll push the grey bit in ready to install cowl

[Andehh]

Push the grey bit in and scim up to it so it flush with finished ceiling, then the cap just screws in tight. The foam you will see on the back of the white suck/blow plates compress against your paint work. 

 

Screwing the suck/blow plates on takes a bit of faff to get the hang of it, line up the prongs with the grooves to help. 

 

I had exactly the same confusion!! 

Edited August 26, 2023 by Andehh

[jfb]

19 hours ago, richo106 said:

 I’ll trim my outlets about 3mm below plasterboard level.

Definitely don’t leave 3mm below plasterboard level, just cut it level or slightly recessed. Much easier to plaster and makes no difference to vent going in.

[MikeGrahamT21]

+1 for flush, would be a nightmare plastering round the duct

Edited August 27, 2023 by MikeGrahamT21

[richo106]

Thanks all for the comments, do I push the grey bit in before or after skimming? 
 

Many Thanks 

[eandg]

We have just had our second fix done after decoration - didn't see any value in taking them off before and the capped ducts prevent any construction stoor getting into the system before it's commissioned. 

[MikeGrahamT21]

12 hours ago, richo106 said:

Thanks all for the comments, do I push the grey bit in before or after skimming? 
 

Many Thanks 

The grey metal part goes on after skimming, and screws into the ceiling, then the white bit screws into the grey bit right at the end.

[catrionag]

14 hours ago, richo106 said:

Thanks all for the comments, do I push the grey bit in before or after skimming? 
 

Many Thanks 

Our supplier recommended a bead of fireproof sealant on the outside of the grey bit before pushing it in. Then we secured with a self tapping screw at around 45 degrees. White bits just screw in at the end - the two different profiles are for supply and extract, can't remember which is which off the top of my head but hopefully someone will be able to tell you!

All this was after decoration etc.

[Andehh]

The large disk is your vent (blow), the small inset disk one is your extract (suck). 

 

Also the paint scratches very easily... So handle them with care. 

Edited August 28, 2023 by Andehh

[richo106]

Thank you all!

 

Much appreciated