Kidde ones on TLC website use a mounting plate [provided with alarm];
this has knockouts for standard dry lining boxes[round or square];
this of course assumes you have the ceiling void access available to
you.

They have loose battery back up or sealed in Lithium with 10 Year
Guarantee too; well worth extra cost.

If not, you'd need the surface pattress too; this is fixed to ceiling,
and accepts mini trunking entry; the pattress has 4 way terminal block
in.
Cable harness with alarm plugs into back of alarms, and flying leads
{3] go into terminal block.

With drylining recessed box you provide the term block; Regs demand
this must be fixed; ensure your dry lining box has peg in for term
block to slide onto.

More guidance at:
www.smoke-alarms.co.uk

At least TLC's are well known brand, from a UK company..unlike unknown
ones on Screwfix..that's if you can even access web site.

TLC sell ceiling rose type, but thats not Kitemarked [essential with
safety products] and is only in Ionisation type.

wrote in message ...
I'm aiming to buy quite a few smoke (and probably heat) alarms in the
coming week or so. These are for a duplex flat and for our house.

It's very difficult looking at web pages of suppliers to work out which
ranges are compatible regarding interconnection etc. The Screwfix web
site (and catalogue) are hopeless on this front. TLC is better but
still not perfect.

It's also not at all clear how they're mounted in many cases. I can
understand the requirement for the pattress if they're surface mounted
but how do you mount them if they're not surface mounted? Do they
mount on 'standard' electrical back boxes?

So I'd appreciate some help in choosing a suitable range.

For the flat I want one Ionisation detector, one optical detector and
(maybe) a heat detector. If it's possible to get the two smoke
detectors as the type that doubles as a ceiling rose for a light
fitting that would be ideal.

For the house I want at least two of each type of smoke detector and
one heat detector, I might decide to add some more smoke detectors for
the more 'out of the way' bedrooms. What's the best type for
bedrooms, I'd guess optical rather than ionisation, is that right?

Oh, and I think I'm going to go for lithium battery backed up mains
devices.


Any recommendations for good ranges of compatible alarms would be very
welcome. E.g. I need (if possible) a range of mains alarms with
lithium battery backup which includes:-

Optical smoke detector
Ionisation smoke detector
Heat Alarm

I'd like to be able to mix and match different mounting types and have
some which are 'pseudo ceiling rose' alarms.