Hi

[Preamble, Questions at end]

We're going to move in with my Dad next year - we're redoing bits of the
dormer loft conversion of his bungalow.

Now, upon inspection, the current insulation in the roof voids is manky
glass wool - yuk. Broken, falling away and very dusty.

I hate glass wool, partly as I a) have to get around the voids to fix some
electrics + install networking, and b) I'm going to use the voids as
supplimentary storage space for light items. I find it unpleasant and
a skin irritant. I also don't want the fibers going anywhere near my
baby daughter. Also, it's too knackered to be doing much good.

I also want to insulate the roof, not the floor as I want the voids to run
warm to protect the stuff I'm storing.

So I thought about using either Celotex/Kingspan to 50mm, leaving 50mm
breathing space in the rafters under the tiles - or rockwool slabs.

Rockwool in slab form is possibly less disgusting than glass wool
- at least once fitted (anyone care to comment?) but I believe from
reading around I'll get better insulation with Celotex or it's like at
50mm.

[Questions]

a) What's celotex like to cut - use a knife or a saw?

b) In a fire, does it pose any risk of giving off noxious fumes?

c) Does having an endothermic but still combustible material like
celotex packed around electric cables bother you?

Thanking you kindly :-)

Timbo

--
Tim Southerwood
Website: http://www.dionic.net/

"Tim S" wrote
| c) Does having an endothermic but still combustible material
| like celotex packed around electric cables bother you?

The electric cables will have to be derated for running within insulation.
Lighting cables on a 6A MCB are probably already fairly generously sized,
but 2.5 ring circuit cables willl almost certainly require replacing with
4mm or worse (bigger).

Owain

"Tim S" wrote in message
news
a) What's celotex like to cut - use a knife or a saw?

A read knife will do or the back of a saw ie any old thing.

b) In a fire, does it pose any risk of giving off noxious fumes?

It is widely used in this country which has very high safety regs. But
not trusting anything too carelessly will stand you in good stead.

c) Does having an endothermic but still combustible material like
celotex packed around electric cables bother you?

I would say electric cables are the more hazardous. "They" are still
telling porkies about radio masts. Radio is just the static produced
from electric circuits.

We are doomed. We're doooooooooomed!



--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

In article ,
Tim S writes:

a) What's celotex like to cut - use a knife or a saw?

I found a serrared breadknife was ideal.

b) In a fire, does it pose any risk of giving off noxious fumes?

I recognise the smell of cyanide componds (probably used to
foam it) when cutting it, so I would assume it gives off cyanide
when heated. Personally, I would not use it without a plasterboard
barrier between it and the house occupents. I tried lighting a
thin slither offcut and it burned. Others have said larger pieces
don't burn so well.

c) Does having an endothermic but still combustible material like
celotex packed around electric cables bother you?

Not if adiqately derated. I would not personally let PVC cables
come into contact with the expanded material incase there's any
long term degredation, not that I know of any. Where I've used
cable near Kingspan, I put it in PVC conduit, but that was more
for ease of rethreading cables if I wanted to chance the wiring
plan.

--
Andrew Gabriel

"Tim S" wrote in message
news

So I thought about using either Celotex/Kingspan to 50mm, leaving 50mm
breathing space in the rafters under the tiles - or rockwool slabs.

I have done same with Celotex - roof and walls behind plasterboard. It
insulates superbly (though you need a bit more than 50mm to meet latest
building regs if you have to) but it is a doddle to fit. Yes it does give
off fumes when ignited but does not sustain the flame on its own so it's as
safe as most other materials in the house.

If it isn't a new build contact "Seconds and Co" (use google) who supply
rejects - usually a mm or two too thin but a lot cheaper.

"Tim S" wrote in message
news
Hi

[Preamble, Questions at end]

We're going to move in with my Dad next year - we're redoing bits of the
dormer loft conversion of his bungalow.

Now, upon inspection, the current insulation in the roof voids is manky
glass wool - yuk. Broken, falling away and very dusty.

I hate glass wool, partly as I a) have to get around the voids to fix some
electrics + install networking, and b) I'm going to use the voids as
supplimentary storage space for light items. I find it unpleasant and
a skin irritant. I also don't want the fibers going anywhere near my
baby daughter. Also, it's too knackered to be doing much good.

I also want to insulate the roof, not the floor as I want the voids to run
warm to protect the stuff I'm storing.

So I thought about using either Celotex/Kingspan to 50mm, leaving 50mm
breathing space in the rafters under the tiles - or rockwool slabs.

Rockwool in slab form is possibly less disgusting than glass wool
- at least once fitted (anyone care to comment?) but I believe from
reading around I'll get better insulation with Celotex or it's like at
50mm.

[Questions]

a) What's celotex like to cut - use a knife or a saw?

b) In a fire, does it pose any risk of giving off noxious fumes?

c) Does having an endothermic but still combustible material like
celotex packed around electric cables bother you?

Thanking you kindly :-)

Timbo

Have from the inside: plasterboard and a vapour barrier under. between the
vapour barrier and the rafters have a layer of Celotex. Between the rafter
have Celotex. Between the Celotex and the tiles/felt have a 25mm
ventilation gap. This arrangement must continue down to the eves, so air can
enter the ventilation gap, but not into the loft space.

Have the internal plaster, VB and insulation form a flat section at the top
of the loft, leaving a triangular section inside the loft at the apex.
Then, if two gable walls, install a vent in each gable at each end of the
triangular section. Then air from the eaves rises up the between the
rafters, enters the triangular section out via the ends through the gable
vents. If no gable ends then have ridge tile vents.

Have the loft "sealed" from air ingress via the ventilation. A highly
insulated loft should result, without any fear of condensation occurring
anywhere.

On Sun, 11 Apr 2004 20:38:58 +0100, G&M wrote:


"Tim S" wrote in message
news

So I thought about using either Celotex/Kingspan to 50mm, leaving 50mm
breathing space in the rafters under the tiles - or rockwool slabs.

I have done same with Celotex - roof and walls behind plasterboard. It
insulates superbly (though you need a bit more than 50mm to meet latest
building regs if you have to) but it is a doddle to fit. Yes it does give
off fumes when ignited but does not sustain the flame on its own so it's as
safe as most other materials in the house.

If it isn't a new build contact "Seconds and Co" (use google) who supply
rejects - usually a mm or two too thin but a lot cheaper.

Fortunately Building Regs don't matter here - the Seconds and Co is a
useful tip - I'll check them out. At 30 quid a sheet, Celotex is normally
an expensive option.

Cheers

Tim

--
Tim Southerwood
Website: http://www.dionic.net/

On Mon, 12 Apr 2004 14:01:33 +0100, Tim S wrote:

On Sun, 11 Apr 2004 20:38:58 +0100, G&M wrote:


"Tim S" wrote in message
news

So I thought about using either Celotex/Kingspan to 50mm, leaving 50mm
breathing space in the rafters under the tiles - or rockwool slabs.

I have done same with Celotex - roof and walls behind plasterboard. It
insulates superbly (though you need a bit more than 50mm to meet latest
building regs if you have to) but it is a doddle to fit. Yes it does give
off fumes when ignited but does not sustain the flame on its own so it's as
safe as most other materials in the house.

If it isn't a new build contact "Seconds and Co" (use google) who supply
rejects - usually a mm or two too thin but a lot cheaper.

Fortunately Building Regs don't matter here - the Seconds and Co is a
useful tip - I'll check them out. At 30 quid a sheet, Celotex is normally
an expensive option.

Cheers

Tim

You can get 50mm from a builder's merchant for £15-18 if you squeeze
them a bit....






..andy

To email, substitute .nospam with .gl

On Sun, 11 Apr 2004 16:14:45 +0000, Andrew Gabriel wrote:

In article ,
Tim S writes:

a) What's celotex like to cut - use a knife or a saw?

I found a serrared breadknife was ideal.


That sounds easy :-)

b) In a fire, does it pose any risk of giving off noxious fumes?

I recognise the smell of cyanide componds (probably used to
foam it) when cutting it, so I would assume it gives off cyanide
when heated. Personally, I would not use it without a plasterboard
barrier between it and the house occupents. I tried lighting a
thin slither offcut and it burned. Others have said larger pieces
don't burn so well.


I am thinking of a thin plasterboard finish, even in the loft. My thinking
is, if it doesn't give out fumes until a fire is well established, that's
good enough, because I'll be toast by then anyway. For my daughter's and
wife's benefit, I'll probably put in a good interlinked fire alarm system
too, including smoke detectors in the voids.

c) Does having an
endothermic but still combustible material like
celotex packed around electric cables bother you?

Not if adiqately derated. I would not personally let PVC cables come
into contact with the expanded material incase there's any long term
degredation, not that I know of any. Where I've used cable near
Kingspan, I put it in PVC conduit, but that was more for ease of
rethreading cables if I wanted to chance the wiring plan.

Fortunately, electrics are my strong point, and all the buried cables will
be lighting. The rest will go on cable trays on the surface. The loft void
is continuous around the permimeter, which is a dream for routing cables
and pipes.

Many thanks

Timbo

--
Tim Southerwood
Website: http://www.dionic.net/

Many thanks to everyone for comments. Celeotex sounds OK so I'll probably
go for it.

Cheers

Timbo

--
Tim Southerwood
Website: http://www.dionic.net/

On Tue, 13 Apr 2004 13:31:04 +0100, "tom patton"
wrote:


If you are planning to board the roof with Cellotex--do nt plan to stay in
the house!!.
I own a 1970s bungalow boarded in Cellotex--its a disaster!!.
Water plus cardboard--tears at bedtime!.



That's curious. considering that it consists of polyisocyanurate foam
and aluminium foil.

I think that you might be thinking of something else.....


..andy

To email, substitute .nospam with .gl

If you are planning to board the roof with Cellotex--do nt plan to stay in
the house!!.
I own a 1970s bungalow boarded in Cellotex--its a disaster!!.
Water plus cardboard--tears at bedtime!.