I intend to insulation my timber framed shed/workshop with rockwool
insulation and would like to know if I should put a vapour barrier
between the insulation and the interior panelling, which will most
likely be plywood?


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

"Lawrence Zarb" wrote in message
news:41edd0ead54e2b6572d66e31803bbbc0.52329@mygate .mailgate.org

I intend to insulation my timber framed shed/workshop with rockwool
insulation and would like to know if I should put a vapour barrier
between the insulation and the interior panelling, which will most
likely be plywood?

........




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

On Sun, 11 Mar 2007 09:42:01 +0000 (UTC), "Lawrence Zarb"
wrote:

I intend to insulation my timber framed shed/workshop with rockwool
insulation and would like to know if I should put a vapour barrier
between the insulation and the interior panelling, which will most
likely be plywood?

Yes. However, do make sure that the space behind is ventilated and
that the outer layer isn't allowing rain to penetrate first.

A hose and sprinkler played on the outside wall are helpful to
determine this.


--

..andy

Thanks for the quick reply....This is a new build but I will check for
"leaks".

What should the thickness should the membrane be...can I use polythene
dust sheets, or should a get the "proper stuff" ?


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

Lawrence Zarb wrote:
Thanks for the quick reply....This is a new build but I will check for
"leaks".

What should the thickness should the membrane be...can I use polythene
dust sheets, or should a get the "proper stuff" ?

Get proper Damp Proofing Membrane - and plan for some left over, for
it's handy stuff to have around.


--
Ian White

On Sun, 11 Mar 2007 10:11:04 +0000 (UTC), "Lawrence Zarb"
wrote:

Thanks for the quick reply....This is a new build but I will check for
"leaks".

What should the thickness should the membrane be...can I use polythene
dust sheets, or should a get the "proper stuff" ?

The polythene dust sheets that I've seen are pretty thin, so I would
err towards the correct material - it's not expensive.

Alternatively, if you use Celotex/Kingspan rather than Rockwool, it
has a foil barrier anyway.




--

..andy

On Sun, 11 Mar 2007 10:22:49 +0000, Andy Hall
wrote:

On Sun, 11 Mar 2007 10:11:04 +0000 (UTC), "Lawrence Zarb"
wrote:

Thanks for the quick reply....This is a new build but I will check for
"leaks".

What should the thickness should the membrane be...can I use polythene
dust sheets, or should a get the "proper stuff" ?

The polythene dust sheets that I've seen are pretty thin, so I would
err towards the correct material - it's not expensive.

Be and queue sell varying thicknesses of plastic sheets and they are
all cheaper than the damp proof stuff they sell (its about £3 for a
fairly thick sheet i think)

Alternatively, if you use Celotex/Kingspan rather than Rockwool, it
has a foil barrier anyway.

I was discussing shed insulation with a mate last night. Can you use
polystyrene sheets as insulation as surely they are cheaper than
anything else - and does polystyrene work well?

In message lgate.org,
at 09:48:31 on Sun, 11 Mar 2007, Lawrence Zarb
wibbled
"Lawrence Zarb" wrote in message
news:41edd0ead54e2b6572d66e31803bbbc0.52329@mygat e.mailgate.org

I intend to insulation my timber framed shed/workshop with rockwool
insulation and would like to know if I should put a vapour barrier
between the insulation and the interior panelling, which will most
likely be plywood?

.......

Plywood is unlikely be hfrshy as a vapour barrier.

--
Pedt

The panelling will be plywood not the vapour barrier!


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

On Sun, 11 Mar 2007 11:32:23 +0000, Tom Woods
wrote:

On Sun, 11 Mar 2007 10:22:49 +0000, Andy Hall
wrote:

On Sun, 11 Mar 2007 10:11:04 +0000 (UTC), "Lawrence Zarb"
wrote:

Thanks for the quick reply....This is a new build but I will check for
"leaks".

What should the thickness should the membrane be...can I use polythene
dust sheets, or should a get the "proper stuff" ?

The polythene dust sheets that I've seen are pretty thin, so I would
err towards the correct material - it's not expensive.

Be and queue sell varying thicknesses of plastic sheets and they are
all cheaper than the damp proof stuff they sell (its about £3 for a
fairly thick sheet i think)

I wouldn't use B&Q as a price guide for anything. An enquiry to a
heavy side builders merchant should give more realistic prices.


Alternatively, if you use Celotex/Kingspan rather than Rockwool, it
has a foil barrier anyway.

I was discussing shed insulation with a mate last night. Can you use
polystyrene sheets as insulation as surely they are cheaper than
anything else - and does polystyrene work well?

You can use expanded polystyrene sheets, although there is the
question of fire risk. Vapour barrier is still needed.

The second point is that Celotex has almost twice the insulating
property for a given thickness as compared with Jablite (polystyrene
normally used under floors)

I did the calculations for this when insulating my garage for use as a
workshop and the insulating property of the sheet material is the
major determinant in the amount of heat required to maintain a given
temperature.

Take a look at this document

http://www.celotex.co.uk/downloads/T...WallLining.pdf

On the first page, there is a list of the components which are used in
a full calculation of heat loss. The R values represent the thermal
resistance of each component. You can see that in this example, the
80mm Celotex has an R value of 3.4 m^2.K/W, with the next nearest
thing being the air cavity at 0.665 and another sheet of Celotex (if
used) at 0.5. All of the rest is almost insignificant in the
calculation.

If you were to use this method of construction, with all of these
components, you would end up with a U value (reciprocal of the sum of
the R values) of better than 0.25 (design goal for a house).

However, the point is clearly that the insulation is almost the sole
determinant.

However, for the application, I was not setting out to achieve house
values (it's not habitable space) and I was also looking at costs of
materials and running and also space taken up by the material itself,
which I wanted to mimimise.

I did some calculations based on using 50mm Celotex (R value is 2.15)
and worked out that I could reduce the heat requirement to around
2-3kW worst case from 12kW as it had been without insulation. A huge
difference. Reducing it further from that to under 2kW wasn't worth
it given the costs and pattern of use.

I also looked at the Jablite web site and to achieve the same
insulating property, one would need just under 100mm thick material.
I didn't want to waste that much space and I did feel that with the
convenience of built in vapour barrier, the Celotex was worth the
investment.


--

..andy

Tom Woods wrote:

I was discussing shed insulation with a mate last night. Can you use
polystyrene sheets as insulation as surely they are cheaper than
anything else - and does polystyrene work well?

The short answer is that polystyrene can work well... it depends a bit
on what you are aiming to achieve.

As Andy said, the PIR foam (Celotex etc) will give better insulation,
however the importance of that will vary with the size of the building
and the amount of use you plan to make of it. So if you heating
requirement with jablite is 1kW spending the extra to reduce it to 600W
may not be worth it in a building for occasional use.

(Having said that, since I built the workshop I have found a local
source of PIR foam at the same price as I paid the builders merchant for
jablite - so in that sense using the better stuff becomes a no brainer)

When I built my workshop (8' x 14'10') I used 50mm jablite in the walls
and the roof. I had decent quality 3/4" shiplap on the outside, and
relied on the jablite as a vapour barrier as well. I left a 1" airgap
(although I placed this on the inside so that it left a convienient
wiring cavity), and then lined the inside with 1/" ply.

I have been pleasantly surprised just how thermally efficient it is. I
have a wall mounted fan heater in there controlled by a thermostat. I
leave the fan heater set to its lowest power (800W) and the stat set to
about 5 just to keep any moisture and frost at bay. It very rarely kicks
in. When working in there in most weathers, I can have it a reasonable
temperature in under 10 mins just by turning the stat up and not
bothering to increase the power on the heater.

Some piccies he

http://www.internode.co.uk/workshop/phase3.htm

--
Cheers,

John.

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

The message lgate.org
from "Lawrence Zarb" contains these words:

I intend to insulation my timber framed shed/workshop with rockwool
insulation and would like to know if I should put a vapour barrier
between the insulation and the interior panelling, which will most
likely be plywood?

I'd stick it outside the insulation.

--
Skipweasel
We have always been at war with Iran. [George Orwell - almost]

Lawrence Zarb wrote:
"Lawrence Zarb" wrote in message
news:41edd0ead54e2b6572d66e31803bbbc0.52329@mygate .mailgate.org

I intend to insulation my timber framed shed/workshop with rockwool
insulation and would like to know if I should put a vapour barrier
between the insulation and the interior panelling, which will most
likely be plywood?

Vapour barriers should be between the insulation and the warm damp air.
There's probably not much point putting it inside the interior panelling
however so between the interior panelling and the insulation would be
favourite.

--
Malc

"Bother!" said Pooh, and hid Piglet's corpse
http://farcanal.biz/

On Sun, 11 Mar 2007 17:55:03 GMT, Guy King
wrote in :
The message lgate.org
from "Lawrence Zarb" contains these words:

I intend to insulation my timber framed shed/workshop with rockwool
insulation and would like to know if I should put a vapour barrier
between the insulation and the interior panelling, which will most
likely be plywood?

I'd stick it outside the insulation.

Nuh-uh. Probably not a real consideration here where the outside
temp is above freezing much of the year, but at Mawson in '80 the
insulation in the dongas was about 75% ice, in the outside layer, after
years of water vapour diffusing through the styrofoam and freezing when it
got to the outer bits. The one night we hit -33 C all the nailheads in
the wall of my donga sprouted flowers of hoarfrost because the ice had
reached the level of the tips of the nails. The new buildings that were
being built had vapour barriers over the insulation to prevent this.

--
Ivan Reid, School of Engineering & Design, _____________ CMS Collaboration,
Brunel University. ] Room 40-1-B12, CERN
KotPT -- "for stupidity above and beyond the call of duty".

"Dr Ivan D. Reid" wrote in message
...
On Sun, 11 Mar 2007 17:55:03 GMT, Guy King
wrote in :
The message
lgate.org
from "Lawrence Zarb" contains these
words:

I intend to insulation my timber framed shed/workshop with
rockwool
insulation and would like to know if I should put a vapour
barrier
between the insulation and the interior panelling, which will
most
likely be plywood?

I'd stick it outside the insulation.

Nuh-uh. Probably not a real consideration here where the outside
temp is above freezing much of the year, but at Mawson in '80 the
insulation in the dongas was about 75% ice, in the outside layer,
after
years of water vapour diffusing through the styrofoam and freezing
when it
got to the outer bits. The one night we hit -33 C all the nailheads
in
the wall of my donga sprouted flowers of hoarfrost because the ice
had
reached the level of the tips of the nails. The new buildings that
were
being built had vapour barriers over the insulation to prevent this.

--
Ivan Reid, School of Engineering & Design, _____________ CMS
Collaboration,
Brunel University. ] Room
40-1-B12, CERN
KotPT -- "for stupidity above and beyond the call of duty".

Glad to see you are taking note of the experiences of my forebear Sir
Douglas G

There is a webcam at Mawson Sound so you can see for yourself how
taxing the weather is.

A W E Mawson

Dr Ivan D. Reid took things to extremes as usual:

On Sun, 11 Mar 2007 17:55:03 GMT, Guy King
wrote in :
The message lgate.org
from "Lawrence Zarb" contains these words:

I intend to insulation my timber framed shed/workshop
with rockwool insulation and would like to know if I
should put a vapour barrier between the insulation and
the interior panelling, which will most likely be plywood?

I'd stick it outside the insulation.

Nuh-uh. Probably not a real consideration here where the outside
temp is above freezing much of the year, but at Mawson in '80 the
insulation in the dongas was about 75% ice, in the outside layer,
after years of water vapour diffusing through the styrofoam and
freezing when it got to the outer bits. The one night we hit -33 C
all the nailheads in the wall of my donga sprouted flowers of
hoarfrost because the ice had reached the level of the tips of
the nails. The new buildings that were being built had vapour
barriers over the insulation to prevent this.

This moose suspects it all deep ends on the tempera chewers on the
two sides of the wall. We insulated our rifle range and put a
vapour barrier (molished of cut-up dustbin bags stapled to the
timber) on the outer wall (where rain was otherwise likely to
blow in, it being ancient and very terrible overlapping planks),
supported the insulation with stapled-up string, then added a
liner of marine 3-ply on the inside. It jbexed very well, until
the local scrotes burned the place down one night.....

It depends on where the vapour is coming from, and on if it can
evaporate from the insulation without waterlogging it.

Cadbury Moose.
--
"There are some complaints that money can't buy. For everything else,
there's *******Card. Accepted everywhere, especially with mallets."
-- Inquisitor in nan-ae

On Sun, 11 Mar 2007 19:44:29 -0000,
Andrew Mawson
wrote in :

"Dr Ivan D. Reid" wrote in message
...

Nuh-uh. Probably not a real consideration here where the outside
temp is above freezing much of the year, but at Mawson in '80 the
insulation in the dongas was about 75% ice, in the outside layer,
after
years of water vapour diffusing through the styrofoam and freezing
when it
got to the outer bits. The one night we hit -33 C all the nailheads
in
the wall of my donga sprouted flowers of hoarfrost because the ice
had
reached the level of the tips of the nails. The new buildings that
were
being built had vapour barriers over the insulation to prevent this.

Glad to see you are taking note of the experiences of my forebear Sir
Douglas G

The Home of the Blizzard. brr!

There is a webcam at Mawson Sound so you can see for yourself how
taxing the weather is.

Not sure if Mawson Sound is at Mawson Base or at Commonwealth Bay
where the original Mawson Expedition huts are -- Google finds very few
references. I was at Mawson Base which is nearly as windy as Commonwealth
Bay -- our average wind speed was around 33 knots so the monthly wind run
would have circumnavigated the Equator!

A W E Mawson

Is your nickname "Shock and"? ;-)

--
Ivan Reid, School of Engineering & Design, _____________ CMS Collaboration,
Brunel University. ] Room 40-1-B12, CERN
KotPT -- "for stupidity above and beyond the call of duty".

"Dr Ivan D. Reid" wrote in message
...
On Sun, 11 Mar 2007 19:44:29 -0000,
Andrew Mawson
wrote in :

"Dr Ivan D. Reid" wrote in message
...

Nuh-uh. Probably not a real consideration here where the outside
temp is above freezing much of the year, but at Mawson in '80 the
insulation in the dongas was about 75% ice, in the outside layer,
after
years of water vapour diffusing through the styrofoam and
freezing
when it
got to the outer bits. The one night we hit -33 C all the
nailheads
in
the wall of my donga sprouted flowers of hoarfrost because the
ice
had
reached the level of the tips of the nails. The new buildings
that
were
being built had vapour barriers over the insulation to prevent
this.

Glad to see you are taking note of the experiences of my forebear
Sir
Douglas G

The Home of the Blizzard. brr!

There is a webcam at Mawson Sound so you can see for yourself how
taxing the weather is.

Not sure if Mawson Sound is at Mawson Base or at Commonwealth Bay
where the original Mawson Expedition huts are -- Google finds very
few
references. I was at Mawson Base which is nearly as windy as
Commonwealth
Bay -- our average wind speed was around 33 knots so the monthly
wind run
would have circumnavigated the Equator!

A W E Mawson

Is your nickname "Shock and"? ;-)

--
Ivan Reid, School of Engineering & Design, _____________ CMS
Collaboration,
Brunel University. ] Room
40-1-B12, CERN
KotPT -- "for stupidity above and beyond the call of duty".

Nice chilly view:

http://www.aad.gov.au/asset/webcams/mawson/default.asp

AWEM

What has all this got to do with inserting a vapour barrier in a shed?


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

The message lgate.org
from "Lawrence Zarb" contains these words:

What has all this got to do with inserting a vapour barrier in a shed?

You're the one who crossposted to the shed. What did you expect,
on-topic answers? (insert smiley of choice here)

--
Skipweasel
We have always been at war with Iran. [George Orwell - almost]

On Mon, 12 Mar 2007 07:52:33 -0000,
Andrew Mawson
wrote in :

Nice chilly view:

http://www.aad.gov.au/asset/webcams/mawson/default.asp

I barely recognise that -- we were building the Big Red Shed in '80
so that helps. Most of the coloured buildings are new, as is the wind
turbine[1]. And it's not chilly, it's -7 C -- that's nearly shorts-'n'-
shirts weather after nine months at -25.

[1] Went to a talk about renewable energy last week. In order to avoid
unreliable gearboxes, wind turbines now use PM generators and will be
using high-temperature superconductor coils by 2010, liquid-helium cooled.
I guess that'd be easier to do at Mawson!

--
Ivan Reid, School of Engineering & Design, _____________ CMS Collaboration,
Brunel University. ] Room 40-1-B12, CERN
KotPT -- "for stupidity above and beyond the call of duty".

On Mon, 12 Mar 2007 08:18:46 +0000 (UTC), "Lawrence Zarb"
wrote:



What has all this got to do with inserting a vapour barrier in a shed?

Obvious really.

The vapour barrier relates to the insulation which relates to the
shed. The purpose of the insulation in the shed is to make it a bit
more cosy when out there in the winter.

The references to expeditions are a means of testing that. Begin
with two people inside. After a short while, one says that he's
going outside and that he may be some time. One would like to know
how long that might be, in order to know whether to make two cups of
tea or just the one.


--

..andy

"Andy Hall" wrote in message
...
On Mon, 12 Mar 2007 08:18:46 +0000 (UTC), "Lawrence Zarb"
wrote:



What has all this got to do with inserting a vapour barrier in a
shed?

Obvious really.

The vapour barrier relates to the insulation which relates to the
shed. The purpose of the insulation in the shed is to make it a
bit
more cosy when out there in the winter.

The references to expeditions are a means of testing that. Begin
with two people inside. After a short while, one says that he's
going outside and that he may be some time. One would like to know
how long that might be, in order to know whether to make two cups of
tea or just the one.


--

.andy


...perhaps he was going to get more teabags? G

AWEM

In article , Andrew Mawson andrew@no_sp
am_please_mawson.org.uk writes
"Andy Hall" wrote in message
.. .
On Mon, 12 Mar 2007 08:18:46 +0000 (UTC), "Lawrence Zarb"
wrote:

What has all this got to do with inserting a vapour barrier in a
shed?

Obvious really.

The vapour barrier relates to the insulation which relates to the
shed. The purpose of the insulation in the shed is to make it a
bit
more cosy when out there in the winter.

The references to expeditions are a means of testing that. Begin
with two people inside. After a short while, one says that he's
going outside and that he may be some time. One would like to know
how long that might be, in order to know whether to make two cups of
tea or just the one.

..perhaps he was going to get more teabags? G

"I may get some Typhoo", he really said.
--
Roger Hunt