Fire rated circular dry lining box for mains fire alarms?

[frusc]

The mains powered, interlinked fire alarms in my house have started to fail so I picked up some Kidde KF1/2/3's to replace them. I couldnt find ones to match the originals and given they were interlinked, I thought it best to replace them all anyway.

The problem is the connector for the Kidde alarms is longer so it protrudes in the ceiling. Whereas the originals the connector didn't protrude past the mounting plate. As a result the sparky appears to have taken a shortcut, cut a small hole to allow the wire to pass through the ceiling, terminated with connector and then partially filled with some sort of intumescent material.

Kidde suggest using a dry lining box and most threads I've been reading suggest trying a circular dry lining box (so I can just use a hole saw, making it easier now I can't get access from above). But I can't find any fire rated circular boxes. My property is over 3 floors, so thus far all down lights/etc (even doors) I'v stuck to installing fire rated.

Any suggestions?

 

[OwainDIYer]

steel conduit box.

 

[flameport]

Normal box and fit one of these in it:
http://www.alertelectrical.com/prod/4488/aurora-fire-rated-intumescent-conduit-box-gasket-blue

 

[frusc]

Thanks for the replies.

I looked at the steel boxes but couldn't find any circular ones. Given I have no access from above, want to cut the smallest hole possible and have a hole saw would ideally like to use the circular type.

I think the Gasket looks like the best bet at this stage. Should have paid more attention when the alarms were originally installed, as I did with the lighting, speakers, etc Atleast the Gaskets are a relatively painless solution.

Going to pop down to screwfix and check their boxes to see if they'll work with one of the alarm back plates:

http://www.screwfix.com/p/round-dry...tracking url&gclid=CLme-NDUir4CFaoewwodND0AnQ

Has anyone tried their offerings for something like this?

 

[frusc]

Just to update this thread for those facing a similar issue:

I haven't found a perfect solution

The Appleby circular dry lining boxes coupled with the intumescent gasket is the closest I've got. The main issue is the screw centres on the Appleby boxes are about 8mm too close to allow me to fix the box to the Kidde KF1 mounting plate. (I picked up one to have a look).

I think I'm going to proceed with this solution none the less, as there is some recess space in parts of the Kidde mountain plate. So I can use some small batons in that space to fix the Appleby box to. Then use the supplied plugs and screws to fix the plate to the ceiling directly. Annoying as if the screw centres on the Appleby were just a little bigger I could have simply mounted the plate directly to them

 

[DaftPunk]

You can get steel fire rated 1 gang dry liners which a smoke alarm will cover

 

[EFLImpudence]

And purpose made pattress boxes for these alarms.

http://www.kiddefirex.co.uk/utcfs/T...te-54/0,8063,pageId=68560&siteId=5250,00.html

 

[securespark]

MT do them integrated into the boxes:

http://www.marshall-tufflex.com/pdfs/009.pdf

 

[frusc]

You can get steel fire rated 1 gang dry liners which a smoke alarm will cover

I've got several to install (big house) and it would be much easier using a hole saw then trying to cut holes to accommodate the square boxes (I don't have access from above anymore). Also its a slightly smaller hole, when using the round boxes.

 

[frusc]

And purpose made pattress boxes for these alarms.

http://www.kiddefirex.co.uk/utcfs/T...8063,pageId=68560&siteId=5250,00.html[/QUOTE]

They're already bigger then the old ones, I'm worried with the surface mount pattress they'll look massive. Although I guess its the most painless route.

 

[frusc]

MT do them integrated into the boxes:

http://www.marshall-tufflex.com/pdfs/009.pdf[/QUOTE]

Thanks I hadn't seen those, they might work well for me

 

[securespark]

Although they may have the same centres as the Appleby boxes...

 

[frusc]

Although they may have the same centres as the Appleby boxes...

Hopefully not, I've emailed them for further details.

Ideally don't want to use the Kidde Pattresses as the alarms are already bigger then what they're replacing. But I guess that would be the simplest solution :/

 

[OwainDIYer]

Thanks for the replies.

I looked at the steel boxes but couldn't find any circular ones.

http://www.tlc-direct.co.uk/Products/CO20BX1G.html

 

[frusc]

Well not a good start on the MT box router. None of the suppliers they pointed to hold them in stock. Online I can only find the MDCRB1 (version without intumescent material) and it appears to be £4.50 :/ If thats indicative of true cost, they'll end up costing almost as much as the alarms.

Oh and no indication on the distance between screw centres.