I am planning a loft conversion in the next year or two and will get plans
drawn up nearer the date but I am doing some homework of my own to check if
the idea if feasible/ affordable.
I have looked at the building regulations and have a couple of questions

1. in the old regs there was a table of joist sizes for various spans, in
the new regs this is now a trada publication (you have to buy separately)
does any one know the figures have changed or would I just be paying 17-50
for tables I already have.

2. Smoke alarms have to be mains powered and linked, my house will end up 3
storeys high so can I use t&e or have to use pyro.

Thanks

Andy

"Andrew Carr" wrote in message
...
I am planning a loft conversion in the next year or two and will get plans
drawn up nearer the date but I am doing some homework of my own to check
if
the idea if feasible/ affordable.
I have looked at the building regulations and have a couple of questions

1. in the old regs there was a table of joist sizes for various spans, in
the new regs this is now a trada publication (you have to buy separately)
does any one know the figures have changed or would I just be paying 17-50
for tables I already have.


Might this help?
http://www.ilevel.com/literature/UK1001.pdf


2. Smoke alarms have to be mains powered and linked, my house will end up
3
storeys high so can I use t&e or have to use pyro.

How long will T & G last in an inferno?

"Andrew Carr" wrote in message
...
I am planning a loft conversion in the next year or two and will get plans
drawn up nearer the date but I am doing some homework of my own to check
if
the idea if feasible/ affordable.
I have looked at the building regulations and have a couple of questions

1. in the old regs there was a table of joist sizes for various spans, in
the new regs this is now a trada publication (you have to buy separately)
does any one know the figures have changed or would I just be paying 17-50
for tables I already have.

2. Smoke alarms have to be mains powered and linked, my house will end up
3
storeys high so can I use t&e or have to use pyro.

Thanks

Andy

Smoke alarms are wired in 3 core and earth 1.00mm T and earth cable. each
alarm has it's own standby battery.By the time the alarms melt and stop
working with the 'heat' you will no longer be alive !

On Tue, 26 Dec 2006 11:49:54 -0000, Robbo wrote:

How long will T & G last in an inferno?

IMHO long enough for the smokes to have been triggered and everyone out.
Seems rather pointless using pyro for a pure alarm in a small property.
Now alarms or maintained lighting in a large place is another matter...

--
Cheers
Dave. pam is missing e-mail

john wrote:

Smoke alarms are wired in 3 core and earth 1.00mm T and earth cable. each
alarm has it's own standby battery.By the time the alarms melt and stop
working with the 'heat' you will no longer be alive !

Although sensible, IIUC there is no actual requirement for the alarms to
have a battery backup. They should have their own circuit however.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Dave Liquorice" wrote in message
ll.com...
On Tue, 26 Dec 2006 11:49:54 -0000, Robbo wrote:

How long will T & G last in an inferno?

IMHO long enough for the smokes to have been triggered and everyone out.
Seems rather pointless using pyro for a pure alarm in a small property.
Now alarms or maintained lighting in a large place is another matter...

Very true, and there are probably more legal implications to those areas as
well.

Given the choice, and a few extra seconds for escape I would plum for the
Pyro.

"Robbo" wrote in message
...

"Dave Liquorice" wrote in message
ll.com...
On Tue, 26 Dec 2006 11:49:54 -0000, Robbo wrote:

How long will T & G last in an inferno?

IMHO long enough for the smokes to have been triggered and everyone out.
Seems rather pointless using pyro for a pure alarm in a small property.
Now alarms or maintained lighting in a large place is another matter...

Very true, and there are probably more legal implications to those areas
as well.

Given the choice, and a few extra seconds for escape I would plum for the
Pyro.


I reckon you will change your mind once you see he cost of the materials and
the cost of the labour time to install it.

Owain wrote:

AIUI alarms on their own circuit do not need back-up.

Alarms on a shared (eg lighting) crcuit do need back-up - although on
some it's provided by a whopping big capacitor.

My preference is for a shared circuit with back-up, because if the
lights go out it's more obvious the MCB's tripped.

The local building inspector asks for battery back up mains interlinked
detectors in the Mids. He might be wrong but given that they only cost
marginally more and you will probably only need three, I would
recommend that these are used. Perhaps he is just covering his back as
he would not no if they are on a ddicated circuit.
With regards to the joist spans I would ring building control and ask
them what they would be happy with for a given span, centres of joists.
I have found certain inspectors to be very helpful. The old tables were
a very good guide so you could always look up the recommendations on
those. That way you could ask if 8 by 2 was still alright for a 3.9m
span and at least the inspector will know that you have made some
effort.
Regards
Legin

Owain wrote:
John Rumm wrote:
Smoke alarms are wired in 3 core and earth 1.00mm T and earth cable.
each alarm has it's own standby battery.By the time the alarms melt
and stop working with the 'heat' you will no longer be alive !
Although sensible, IIUC there is no actual requirement for the alarms
to have a battery backup. They should have their own circuit however.

AIUI alarms on their own circuit do not need back-up.

Alarms on a shared (eg lighting) crcuit do need back-up - although on
some it's provided by a whopping big capacitor.

Both correct; as stated in 2000 building regs (Part B). Can't see any
point in not always having the battery backup TBH.

My preference is for a shared circuit with back-up, because if the
lights go out it's more obvious the MCB's tripped.

Yes - it does seem odd to me that on a dedicated alarm circuit you
*don't* need backup, exactly for the above reason. With a numpty
householder the MCB could be permanently switched off and/or tripped and
numpty would never be any the wiser.

David

On Tue, 26 Dec 2006 18:43:53 -0000 Robbo wrote :
Given the choice, and a few extra seconds for escape I would plum for
the Pyro.

Or check out the first option on

http://www.buildingdesign.co.uk/elec...i/pirelli.html

Prysmian FP200 Gold®

A unique fire resistant cable incorporating hard skin Insudite™
insulation. The right choice for fire alarms and emergency lighting
with minimum installed costs. The original, easy to install alternative
to MICC with unmatched combination of rigidity and ease of bending.

I only know about this through seeing the offcuts in next door's skip a
few months back.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

My alarms chrip every so often if the mains power is switched off and
they're running on backup battery only. Useful feature which probably
should be a requirement.