This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?

cheers

"Staffbull" wrote in message
oups.com...
This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?


Plaster does not attack copper so it is not necessary.

--
Mike W

Plaster does not attack copper so it is not necessary.

Although I would be tempted to use plastic for anything buried in a wall.

Christian.

VisionSet wrote:
"Staffbull" wrote in message
oups.com...
This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?


Plaster does not attack copper so it is not necessary.


What about expansion and contraction as the pipes heat up? Doesn't this
crack plaster?

R.

On 2006-10-04 12:35:55 +0100, "Staffbull" said:

This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?

cheers

It is better to sleeve it to allow for expansion; corrosion isn't an issue.

On a side note, have you verified that 10mm tube will carry the
necessary flow rate of water for the distance required and heat output
of the radiators?

Staffbull wrote:
This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?

cheers

Although I guess you probably should take some precautions (not sure what) -
this is what I did some 5 years ago - so far no problems and no cracking etc

Jon

Andy Hall wrote:
On 2006-10-04 12:35:55 +0100, "Staffbull" said:

This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?

cheers

It is better to sleeve it to allow for expansion; corrosion isn't an issue.

On a side note, have you verified that 10mm tube will carry the
necessary flow rate of water for the distance required and heat output
of the radiators?

Hi its 10mm that serve the rest of the house and there are longer runs
than the ones I will be putting in, so should be fine :-)

VisionSet wrote:
"Staffbull" wrote in message
oups.com...
This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?


Plaster does not attack copper so it is not necessary.

--
Mike W

Hi, forgot to mention that there will be 10mm sand cement coat first
then pink

On 2006-10-04 19:17:57 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 12:35:55 +0100, "Staffbull" said:

This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?

cheers

It is better to sleeve it to allow for expansion; corrosion isn't an issue.

On a side note, have you verified that 10mm tube will carry the
necessary flow rate of water for the distance required and heat output
of the radiators?

Hi its 10mm that serve the rest of the house and there are longer runs
than the ones I will be putting in, so should be fine :-)

OK... Have you sized the radiators for the heatloss of the room and
from that the flow required?

It may well all be OK, but it would be very prudent to do the sums
properly and check.

10mm would be OK for a larger number of smaller radiators, but if you
are hoping to have a single 3-4kW radiator, then it is important to
check.

You would be very tearful in a few weeks time if you discovered that
the radiators are not heating the space adequately because they are
undersized and that upgrading to the correct size meant pipes of 10mm

Apologies if I 'm teaching granny to suck eggs, but it wouldn't be the
first time that radiators had been guesstimated and found wanting.

Christian McArdle wrote:
Plaster does not attack copper so it is not necessary.

Although I would be tempted to use plastic for anything buried in a wall.

Christian.

I'd do the usual and wrap the pipe in closure tape before burying it.

Andy Hall wrote:
On 2006-10-04 19:17:57 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 12:35:55 +0100, "Staffbull" said:

This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?

cheers

It is better to sleeve it to allow for expansion; corrosion isn't an issue.

On a side note, have you verified that 10mm tube will carry the
necessary flow rate of water for the distance required and heat output
of the radiators?

Hi its 10mm that serve the rest of the house and there are longer runs
than the ones I will be putting in, so should be fine :-)

OK... Have you sized the radiators for the heatloss of the room and
from that the flow required?

It may well all be OK, but it would be very prudent to do the sums
properly and check.

10mm would be OK for a larger number of smaller radiators, but if you
are hoping to have a single 3-4kW radiator, then it is important to
check.

You would be very tearful in a few weeks time if you discovered that
the radiators are not heating the space adequately because they are
undersized and that upgrading to the correct size meant pipes of 10mm

Apologies if I 'm teaching granny to suck eggs, but it wouldn't be the
first time that radiators had been guesstimated and found wanting.

Cheers, what I'm going off isn't science :-). The furthest fed rad in
the house is the lounge, its a 5ft double and fed off 10mm, with the
trv open and the boiler on "tickover" you cant put your hand on it!.
The upstairs rad will be no issue as it will be an extension (extra 2m)
of an exisiting rad thats been removed from the hall where I knocked
through. The downstairs will be a little bit more hit and miss as it
will be tee'd off an existing rad and will be 6m "downstream". With me
tee'ing off I'm stuck with using the 10mm feed off the exisiting rad (
small 2ft double) both new rads are 4ft doubles. At the moment I have
the trv's set at 2 and the boiler is on its first quater ( if that
makes sense?) and it's fine so I've a long way left to "pump it up".

If I'm way off the mark I'd be glad for any advice.

Ta

On 2006-10-04 20:13:45 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 19:17:57 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 12:35:55 +0100, "Staffbull" said:

This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?

cheers

It is better to sleeve it to allow for expansion; corrosion isn't an issue.

On a side note, have you verified that 10mm tube will carry the
necessary flow rate of water for the distance required and heat output
of the radiators?

Hi its 10mm that serve the rest of the house and there are longer runs
than the ones I will be putting in, so should be fine :-)

OK... Have you sized the radiators for the heatloss of the room and
from that the flow required?

It may well all be OK, but it would be very prudent to do the sums
properly and check.

10mm would be OK for a larger number of smaller radiators, but if you
are hoping to have a single 3-4kW radiator, then it is important to
check.

You would be very tearful in a few weeks time if you discovered that
the radiators are not heating the space adequately because they are
undersized and that upgrading to the correct size meant pipes of 10mm

Apologies if I 'm teaching granny to suck eggs, but it wouldn't be the
first time that radiators had been guesstimated and found wanting.

Cheers, what I'm going off isn't science :-). The furthest fed rad in
the house is the lounge, its a 5ft double and fed off 10mm, with the
trv open and the boiler on "tickover" you cant put your hand on it!.

So far so good.

The upstairs rad will be no issue as it will be an extension (extra 2m)
of an exisiting rad thats been removed from the hall where I knocked
through.

OK, so a larger one than was previously in the hall?



The downstairs will be a little bit more hit and miss as it
will be tee'd off an existing rad and will be 6m "downstream". With me
tee'ing off I'm stuck with using the 10mm feed off the exisiting rad (
small 2ft double) both new rads are 4ft doubles.

Do you know that they will provide adequate heat for the space?


At the moment I have
the trv's set at 2 and the boiler is on its first quater ( if that
makes sense?) and it's fine so I've a long way left to "pump it up".

Unfortunately that's not really the issue. Having a 5ft radiator on a
long run and having adequate heat for the room from it, probably means
that you are OK in terms of being able to feed a 5ft radiator anywhere
in the house. However, a radiator can be very hot on the top, and
because of low flow rate, almost cold on the return pipe. This means
it won't be prviding full output and therefore may not be enough to
warm the room if you have used manufacturer data to choose radiator
size.

The question is whether that radiator size or the 4ft one you propose
will adequately heat the space.
If it doesn't and you needed to go for a 6ft one for example, in order
to get enough heat for the space, then 10mm may not be enough.

Let me give you a simple example. In my conservatory, I have a 5kW
radiator - a large double panel job with fins. All of the other
radiators in the house are connected via 8mm microbore. However,
because of good insulation, none of those are larger than 1500W output.
You can calculate the volume of water required to achieve the output.
It is proportional to the temperature drop across the radiator (12
degrees for a conventional boiler and 20 for a condensing boiler) and
the rate of flow. The important point is that the flow rate must be
enough to maintain the correct temperature drop or the heat output will
be less than that rated. Copper tube can support a maximum flow rate
of 1.5m/sec without becoming noisy. Resistance gets worse with longer
lengths as well. You can calculate the pipe size required to
transport the volume of water needed to provide the heat for the
radiator.

To cut a long story short, because I was short of time, a heating
engineer was hired to connect the radiator. He insisted on using 8mm
tube because that had been used elsewhere and refused to listen to my
arguments that it would be inadequate. When put into operation, the
radiator became hot at the top but the return temperature, was only 50
degrees when it should have been 70. Heating was inadequate. He was
therefore asked to do the job again in the correctly sized 15mm tube.
This cost him half a day and £30 in Fernox.

So I would say, do at least check the heat loss. At a minimum, look
at radiator sizings in other rooms and then scale them according to
floor area for the extension areas. If these make sense and you feel
you have sized radiators adequately and they are less than existing,
then you should be OK.

If undersized, you would have to add more radiators, with pipes home
run back to the manifolds or go for larger radiators and possibly
larger pipes. Realise that if the flow is inadequate, opening the TRVs
won't help. You could improve flow a little by reducing that through
other radiators, but with 10mm pipe the effect of doing that is not as
marked as with 15mm and there is a limit to what can be done.





If I'm way off the mark I'd be glad for any advice.

Ta

Andy Hall wrote:
On 2006-10-04 20:13:45 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 19:17:57 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 12:35:55 +0100, "Staffbull" said:

This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?

cheers

It is better to sleeve it to allow for expansion; corrosion isn't an issue.

On a side note, have you verified that 10mm tube will carry the
necessary flow rate of water for the distance required and heat output
of the radiators?

Hi its 10mm that serve the rest of the house and there are longer runs
than the ones I will be putting in, so should be fine :-)

OK... Have you sized the radiators for the heatloss of the room and
from that the flow required?

It may well all be OK, but it would be very prudent to do the sums
properly and check.

10mm would be OK for a larger number of smaller radiators, but if you
are hoping to have a single 3-4kW radiator, then it is important to
check.

You would be very tearful in a few weeks time if you discovered that
the radiators are not heating the space adequately because they are
undersized and that upgrading to the correct size meant pipes of 10mm

Apologies if I 'm teaching granny to suck eggs, but it wouldn't be the
first time that radiators had been guesstimated and found wanting.

Cheers, what I'm going off isn't science :-). The furthest fed rad in
the house is the lounge, its a 5ft double and fed off 10mm, with the
trv open and the boiler on "tickover" you cant put your hand on it!.

So far so good.

The upstairs rad will be no issue as it will be an extension (extra 2m)
of an exisiting rad thats been removed from the hall where I knocked
through.

OK, so a larger one than was previously in the hall?



The downstairs will be a little bit more hit and miss as it
will be tee'd off an existing rad and will be 6m "downstream". With me
tee'ing off I'm stuck with using the 10mm feed off the exisiting rad (
small 2ft double) both new rads are 4ft doubles.

Do you know that they will provide adequate heat for the space?


At the moment I have
the trv's set at 2 and the boiler is on its first quater ( if that
makes sense?) and it's fine so I've a long way left to "pump it up".

Unfortunately that's not really the issue. Having a 5ft radiator on a
long run and having adequate heat for the room from it, probably means
that you are OK in terms of being able to feed a 5ft radiator anywhere
in the house. However, a radiator can be very hot on the top, and
because of low flow rate, almost cold on the return pipe. This means
it won't be prviding full output and therefore may not be enough to
warm the room if you have used manufacturer data to choose radiator
size.

The question is whether that radiator size or the 4ft one you propose
will adequately heat the space.
If it doesn't and you needed to go for a 6ft one for example, in order
to get enough heat for the space, then 10mm may not be enough.

Let me give you a simple example. In my conservatory, I have a 5kW
radiator - a large double panel job with fins. All of the other
radiators in the house are connected via 8mm microbore. However,
because of good insulation, none of those are larger than 1500W output.
You can calculate the volume of water required to achieve the output.
It is proportional to the temperature drop across the radiator (12
degrees for a conventional boiler and 20 for a condensing boiler) and
the rate of flow. The important point is that the flow rate must be
enough to maintain the correct temperature drop or the heat output will
be less than that rated. Copper tube can support a maximum flow rate
of 1.5m/sec without becoming noisy. Resistance gets worse with longer
lengths as well. You can calculate the pipe size required to
transport the volume of water needed to provide the heat for the
radiator.

To cut a long story short, because I was short of time, a heating
engineer was hired to connect the radiator. He insisted on using 8mm
tube because that had been used elsewhere and refused to listen to my
arguments that it would be inadequate. When put into operation, the
radiator became hot at the top but the return temperature, was only 50
degrees when it should have been 70. Heating was inadequate. He was
therefore asked to do the job again in the correctly sized 15mm tube.
This cost him half a day and £30 in Fernox.

So I would say, do at least check the heat loss. At a minimum, look
at radiator sizings in other rooms and then scale them according to
floor area for the extension areas. If these make sense and you feel
you have sized radiators adequately and they are less than existing,
then you should be OK.

If undersized, you would have to add more radiators, with pipes home
run back to the manifolds or go for larger radiators and possibly
larger pipes. Realise that if the flow is inadequate, opening the TRVs
won't help. You could improve flow a little by reducing that through
other radiators, but with 10mm pipe the effect of doing that is not as
marked as with 15mm and there is a limit to what can be done.



Thanks, the rad sizes are around the same for similar rooms in the
house, apart from the lounge which the heating engineer fitted a 6ft
double ( I said 5 ft in the last post but its 6ft) so in effect a 12ft
rad !! I usually have this on one on the trv as it gets too warm !
Lounge is 5m X 4m, two of the bedrooms are the same size and are heated
very adequately on twin 4 footers, I never really like the house too
warm and we never really get "the freeze" as bad as the rest of the
country as we seem to have our own microclimate on Anglesey and it
helps in the winter being on a small island warmed by the sea !!

On 2006-10-04 21:21:01 +0100, "Staffbull" said:


Thanks, the rad sizes are around the same for similar rooms in the
house, apart from the lounge which the heating engineer fitted a 6ft
double ( I said 5 ft in the last post but its 6ft) so in effect a 12ft
rad !! I usually have this on one on the trv as it gets too warm !
Lounge is 5m X 4m, two of the bedrooms are the same size and are heated
very adequately on twin 4 footers, I never really like the house too
warm and we never really get "the freeze" as bad as the rest of the
country as we seem to have our own microclimate on Anglesey and it
helps in the winter being on a small island warmed by the sea !!

Good. Sounds OK.

However, I once went walking in February near Amlwch and it sleeted
horizontally. ;-)

Should have known better, I suppose. That was in the days when a
bus ride to Llandudno Junction was necessary to find an open pub on a
Sunday.

Staffbull wrote:
VisionSet wrote:
"Staffbull" wrote in message
oups.com...
This weekends fun will be placing the pipes for the two rads in the
extension, will it be OK just to clip the microbore (10mm) to the
surface of the blocks and then just plaster over them or will they
require conduit?

Plaster does not attack copper so it is not necessary.

Hi, forgot to mention that there will be 10mm sand cement coat first
then pink


!!! that's a totally different situation, as sand-cement isn't plaster,
and cement *does* attack copper. So yes, you should definitely wrap
them in 'denso' tape or enclose them in conduit.

David

Andy Hall wrote:
On 2006-10-04 21:21:01 +0100, "Staffbull" said:


Thanks, the rad sizes are around the same for similar rooms in the
house, apart from the lounge which the heating engineer fitted a 6ft
double ( I said 5 ft in the last post but its 6ft) so in effect a 12ft
rad !! I usually have this on one on the trv as it gets too warm !
Lounge is 5m X 4m, two of the bedrooms are the same size and are heated
very adequately on twin 4 footers, I never really like the house too
warm and we never really get "the freeze" as bad as the rest of the
country as we seem to have our own microclimate on Anglesey and it
helps in the winter being on a small island warmed by the sea !!

Good. Sounds OK.

However, I once went walking in February near Amlwch and it sleeted
horizontally. ;-)

Should have known better, I suppose. That was in the days when a
bus ride to Llandudno Junction was necessary to find an open pub on a
Sunday.

Snow never seems to stay for long, probably the salt in the air. Not
quite 24 hr drinking here now but not far off !!

On 2006-10-05 10:28:20 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 21:21:01 +0100, "Staffbull" said:


Thanks, the rad sizes are around the same for similar rooms in the
house, apart from the lounge which the heating engineer fitted a 6ft
double ( I said 5 ft in the last post but its 6ft) so in effect a 12ft
rad !! I usually have this on one on the trv as it gets too warm !
Lounge is 5m X 4m, two of the bedrooms are the same size and are heated
very adequately on twin 4 footers, I never really like the house too
warm and we never really get "the freeze" as bad as the rest of the
country as we seem to have our own microclimate on Anglesey and it
helps in the winter being on a small island warmed by the sea !!

Good. Sounds OK.

However, I once went walking in February near Amlwch and it sleeted
horizontally. ;-)

Should have known better, I suppose. That was in the days when a
bus ride to Llandudno Junction was necessary to find an open pub on a
Sunday.

Snow never seems to stay for long, probably the salt in the air. Not
quite 24 hr drinking here now but not far off !!

I see. Beaumaris?

Andy Hall wrote:
On 2006-10-05 10:28:20 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 21:21:01 +0100, "Staffbull" said:


Thanks, the rad sizes are around the same for similar rooms in the
house, apart from the lounge which the heating engineer fitted a 6ft
double ( I said 5 ft in the last post but its 6ft) so in effect a 12ft
rad !! I usually have this on one on the trv as it gets too warm !
Lounge is 5m X 4m, two of the bedrooms are the same size and are heated
very adequately on twin 4 footers, I never really like the house too
warm and we never really get "the freeze" as bad as the rest of the
country as we seem to have our own microclimate on Anglesey and it
helps in the winter being on a small island warmed by the sea !!

Good. Sounds OK.

However, I once went walking in February near Amlwch and it sleeted
horizontally. ;-)

Should have known better, I suppose. That was in the days when a
bus ride to Llandudno Junction was necessary to find an open pub on a
Sunday.

Snow never seems to stay for long, probably the salt in the air. Not
quite 24 hr drinking here now but not far off !!

I see. Beaumaris?

or if you want to take your life in your hands, have a drink in
Holyhead ;-)

On 2006-10-05 10:54:45 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-05 10:28:20 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 21:21:01 +0100, "Staffbull" said:


Thanks, the rad sizes are around the same for similar rooms in the
house, apart from the lounge which the heating engineer fitted a 6ft
double ( I said 5 ft in the last post but its 6ft) so in effect a 12ft
rad !! I usually have this on one on the trv as it gets too warm !
Lounge is 5m X 4m, two of the bedrooms are the same size and are heated
very adequately on twin 4 footers, I never really like the house too
warm and we never really get "the freeze" as bad as the rest of the
country as we seem to have our own microclimate on Anglesey and it
helps in the winter being on a small island warmed by the sea !!

Good. Sounds OK.

However, I once went walking in February near Amlwch and it sleeted
horizontally. ;-)

Should have known better, I suppose. That was in the days when a
bus ride to Llandudno Junction was necessary to find an open pub on a
Sunday.

Snow never seems to stay for long, probably the salt in the air. Not
quite 24 hr drinking here now but not far off !!

I see. Beaumaris?

or if you want to take your life in your hands, have a drink in
Holyhead ;-)

It seems to have all the trappings of a sea port. :-)

Is that where you are?

Andy Hall wrote:
On 2006-10-05 10:54:45 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-05 10:28:20 +0100, "Staffbull" said:


Andy Hall wrote:
On 2006-10-04 21:21:01 +0100, "Staffbull" said:


Thanks, the rad sizes are around the same for similar rooms in the
house, apart from the lounge which the heating engineer fitted a 6ft
double ( I said 5 ft in the last post but its 6ft) so in effect a 12ft
rad !! I usually have this on one on the trv as it gets too warm !
Lounge is 5m X 4m, two of the bedrooms are the same size and are heated
very adequately on twin 4 footers, I never really like the house too
warm and we never really get "the freeze" as bad as the rest of the
country as we seem to have our own microclimate on Anglesey and it
helps in the winter being on a small island warmed by the sea !!

Good. Sounds OK.

However, I once went walking in February near Amlwch and it sleeted
horizontally. ;-)

Should have known better, I suppose. That was in the days when a
bus ride to Llandudno Junction was necessary to find an open pub on a
Sunday.

Snow never seems to stay for long, probably the salt in the air. Not
quite 24 hr drinking here now but not far off !!

I see. Beaumaris?

or if you want to take your life in your hands, have a drink in
Holyhead ;-)

It seems to have all the trappings of a sea port. :-)

Is that where you are?

no, I'm "east coast"