This weekends project, is to fit underfloor heating into my conservatory
project. I bought a kit from a UK supplier (eco-hometech), and it seems
to have everything I need.

The conservatory area is 18.6sqM and the supplier recommened 3 pipe
sections from the manifold/pump. I have arranged my pipes in a
counterflow pattern, with 100mm centres, and achieved pipe run lengths of
62m, 52m, and 55m

Does this pipe layout seem OK? (excuse the dodgy grid, as it seems Google
Sketchup is incapable of grids)

http://img84.imageshack.us/my.php?im...elayoutsq2.jpg

There are a couple of small runs where the hots run next to each other on
adacent sections, which are hard to avoid. I am asuming this will not be
a big deal.

I really only have one question.

I am clipping the pipes down directly onto celotex foil backed insulation.
I have taped the joins between the foil boards with foil tape. The kit I
have, has edge insulation, and the insulation handbook says the following:

"IMPORTANT: if you are going to use a liquid screed you need to use an
expansion strip with a thin polythene strip attached to it. The polythene
strip must be taped to the membrane that has been laid on top of the
insualtion with specialist floor screed tape to ensure a watertight seal".


Now all that seem quite scary and implies it's important... I will be
using a sand/cement screed, but unsure if this is classed as a "liquid
screed".

So my question is, do I need to do any additional taping/waterproofing
with a sand/cement screed? Or can I just pin the pipes down to the
celotex, and lay the insulation strip around the permiter. Or do I need to
do special stuff.

I think that's all for the moment. Hopefully I have everything prepared,
and I can get most of the kit down this weekend (I might not get the
manifold in, as it's going under the floor in the living room, and it
means lifting floors..)

Any other tips and knowledgable folks here can help with???

Many thanks.

On Fri, 22 Feb 2008 00:03:40 -0000
"Mark Gillespie" wrote:
snip

"IMPORTANT: if you are going to use a liquid screed you need to use an
expansion strip with a thin polythene strip attached to it. The polythene
strip must be taped to the membrane that has been laid on top of the
insualtion with specialist floor screed tape to ensure a watertight seal".


Now all that seem quite scary and implies it's important... I will be
using a sand/cement screed, but unsure if this is classed as a "liquid
screed".

So my question is, do I need to do any additional taping/waterproofing
with a sand/cement screed? Or can I just pin the pipes down to the
celotex, and lay the insulation strip around the permiter. Or do I need to
do special stuff.

I think that's all for the moment. Hopefully I have everything prepared,
and I can get most of the kit down this weekend (I might not get the
manifold in, as it's going under the floor in the living room, and it
means lifting floors..)

Any other tips and knowledgable folks here can help with???

Many thanks.

It's important that the expansion gap round the outside of the slab is
maintained. With a dry-ish screed the mix wont run under the
insulation band, but a slurry will.

If you don't maintain the expansion gap on a 18m2 slab, it will crack
due to expansion, and then the pipes may abrade as the pieces move.

I would just use, say gaffer-tape, to seal the edge insulation to the
celotex, that way your screed can't get into the gap. It doesn't
matter if the seal degrades later, the slab will be set.

The other important, nay VITAL, thing is to let the slab dry AND CURE
well before putting the heat into the pipes. Say 6-8 weeks. I also
pressurise the pipes with water to 6 bar while the screen is laid, and
then for a couple of days - to make sure the pipes don't get kinked or
crushed.

R.

On Fri, 22 Feb 2008 07:57:28 -0000, TheOldFellow
wrote:


It's important that the expansion gap round the outside of the slab is
maintained. With a dry-ish screed the mix wont run under the
insulation band, but a slurry will.

If you don't maintain the expansion gap on a 18m2 slab, it will crack
due to expansion, and then the pipes may abrade as the pieces move.

I would just use, say gaffer-tape, to seal the edge insulation to the
celotex, that way your screed can't get into the gap. It doesn't
matter if the seal degrades later, the slab will be set.

The other important, nay VITAL, thing is to let the slab dry AND CURE
well before putting the heat into the pipes. Say 6-8 weeks. I also
pressurise the pipes with water to 6 bar while the screen is laid, and
then for a couple of days - to make sure the pipes don't get kinked or
crushed.

R.



Many thanks for that! How do you pressurise the system to 6 bar, without
running it? Do I need to buy special kit to do this? I was thinking of
fashioning a valve into a bit of copper pipe and soldering it in, so I can
pump it up to 6 bar of air, with a foot pump. Is there a better way?

--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

I also
pressurise the pipes with water to 6 bar while the screen is laid, and
then for a couple of days - to make sure the pipes don't get kinked or
crushed.

Wouldn't it be easier to keep a dry test gauge on?

http://www.screwfix.com/prods/72940/...ssure-Test-Kit

(pressurise with a car foot pump)

On Fri, 22 Feb 2008 00:31:15 -0800 (PST)
" wrote:

I also
pressurise the pipes with water to 6 bar while the screen is laid, and
then for a couple of days - to make sure the pipes don't get kinked or
crushed.

Wouldn't it be easier to keep a dry test gauge on?

http://www.screwfix.com/prods/72940/...ssure-Test-Kit

(pressurise with a car foot pump)

Well, I have a Rothenberger test-pump that fills and pressurises with
water, then it's already full when you connect it up I guess 6 bar
is 6 bar, though, so an dry test would seem to me to be OK.

Remember I'm a DIYer, not a plumber, though.

R.

On Feb 22, 12:03*am, "Mark Gillespie"
wrote:
This weekends project, is to fit underfloor heating into my conservatory *
project. *I bought a kit from a UK supplier (eco-hometech), and it seems *
to have everything I need.

The conservatory area is 18.6sqM and the supplier recommened 3 pipe *
sections from the manifold/pump. *I have arranged my pipes in a *
counterflow pattern, with 100mm centres, and achieved pipe run lengths of *
62m, 52m, and 55m

Does this pipe layout seem OK? (excuse the dodgy grid, as it seems Google *
Sketchup is incapable of grids)

http://img84.imageshack.us/my.php?im...elayoutsq2.jpg

There are a couple of small runs where the hots run next to each other on *
adacent sections, which are hard to avoid. *I am asuming this will not be *
a big deal.

I really only have one question.

I am clipping the pipes down directly onto celotex foil backed insulation. *
I have taped the joins between the foil boards with foil tape. *The kit I *
have, has edge insulation, and the insulation handbook says the following:

"IMPORTANT: if you are going to use a liquid screed you need to use an *
expansion strip with a thin polythene strip attached to it. *The polythene *
strip must be taped to the membrane that has been laid on top of the *
insualtion with specialist floor screed tape to ensure a watertight seal".

Now all that seem quite scary and implies it's important... *I will be *
using a sand/cement screed, but unsure if this is classed as a "liquid *
screed".

So my question is, do I need to do any additional taping/waterproofing *
with a sand/cement screed? *Or can I just pin the pipes down to the *
celotex, and lay the insulation strip around the permiter. Or do I need to *
do special stuff.

I think that's all for the moment. *Hopefully I have everything prepared, *
and I can get most of the kit down this weekend (I might not get the *
manifold in, as it's going under the floor in the living room, and it *
means lifting floors..)

Any other tips and knowledgable folks here can help with???

Many thanks.

I used the Eco-hometec wet UFH system about 2 yrs ago - and it's still
working!

Unless they've changed their pipework, I'd say some of the angles in
your layout are unachievable. The pipe they used to supply (16mm IIRC)
is really quite stiff, and I don't think you'll get a radius any less
than 50cm.You *really* don't want to put a kink in it. Some of the
acute angles you have in your layout, are too sharp, I think.

Don't worry about tape etc. The clips will hold the pipe in place just
fine. And the screed will hold the edge insulation in place too. Just
make sure whoever does the screed for you doesn't remove it!

Alos, I'd plan to leave a bit of pipe left over. One of the most
stressful times in my project was when I was laying the pipework the
day before the guys were coming to lay the screed. Somehow I was 5m
short. Had to get some more sent by courier, which inevitably was
late. They started laying the screed, and the extra pipe and coupler
arrived just as they got to the bit I was working on.

Everyone says you should pressurise the system. I must admit, I filled
it, but didn't pressurise it. I really didn't see the point. The pipe
is *so* tough. You can stand on it, no problem. And 4 inches of
concrete just ain't that heavy. As you say, pressurising it is a pain.

when it's done though...lovely! :-)

Jon.

In article ,
"Black Shuck" writes:

Many thanks for that! How do you pressurise the system to 6 bar, without
running it? Do I need to buy special kit to do this? I was thinking of
fashioning a valve into a bit of copper pipe and soldering it in, so I can
pump it up to 6 bar of air, with a foot pump. Is there a better way?

I did that using a dry pressure test kit on all the sections of
my heating system before I let any water in.
http://www.screwfix.com/prods/72940/...ssure-Test-Kit
(Part 72940 if that link doesn't work)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Mark Gillespie wrote:
This weekends project, is to fit underfloor heating into my conservatory
project. I bought a kit from a UK supplier (eco-hometech), and it seems
to have everything I need.

The conservatory area is 18.6sqM and the supplier recommened 3 pipe
sections from the manifold/pump. I have arranged my pipes in a
counterflow pattern, with 100mm centres, and achieved pipe run lengths
of 62m, 52m, and 55m

Does this pipe layout seem OK? (excuse the dodgy grid, as it seems
Google Sketchup is incapable of grids)

http://img84.imageshack.us/my.php?im...elayoutsq2.jpg

There are a couple of small runs where the hots run next to each other
on adacent sections, which are hard to avoid. I am asuming this will
not be a big deal.

I really only have one question.

I am clipping the pipes down directly onto celotex foil backed
insulation. I have taped the joins between the foil boards with foil
tape. The kit I have, has edge insulation, and the insulation handbook
says the following:

"IMPORTANT: if you are going to use a liquid screed you need to use an
expansion strip with a thin polythene strip attached to it. The
polythene strip must be taped to the membrane that has been laid on top
of the insualtion with specialist floor screed tape to ensure a
watertight seal".


Now all that seem quite scary and implies it's important... I will be
using a sand/cement screed, but unsure if this is classed as a "liquid
screed".


No. What they are saying is 'take precautions to prevent any screed
getting behind the expansion strip'


So my question is, do I need to do any additional taping/waterproofing
with a sand/cement screed? Or can I just pin the pipes down to the
celotex, and lay the insulation strip around the permiter. Or do I need
to do special stuff.

I think that's all for the moment. Hopefully I have everything
prepared, and I can get most of the kit down this weekend (I might not
get the manifold in, as it's going under the floor in the living room,
and it means lifting floors..)

Any other tips and knowledgable folks here can help with???

Many thanks.

wrote:
I also
pressurise the pipes with water to 6 bar while the screen is laid, and
then for a couple of days - to make sure the pipes don't get kinked or
crushed.

Wouldn't it be easier to keep a dry test gauge on?

http://www.screwfix.com/prods/72940/...ssure-Test-Kit

(pressurise with a car foot pump)

Far more dangerous. Air is compressible and contains energy when
compressed. Water is not and doesn't, largely.


I hired my gauge and hydraulic pump for a fiver or so for the day it
took to lay the screed..leave pressure on about 24 hrs.

Letting screed dry is a good idea, but its not necessary that its DRY,
its necessary that its fully set. 6-8 weeks is 'proper' but I think you
would get away with one in practice.

Tournifreak wrote:
On Feb 22, 12:03 am, "Mark Gillespie"
wrote:
This weekends project, is to fit underfloor heating into my conservatory
project. I bought a kit from a UK supplier (eco-hometech), and it seems
to have everything I need.

The conservatory area is 18.6sqM and the supplier recommened 3 pipe
sections from the manifold/pump. I have arranged my pipes in a
counterflow pattern, with 100mm centres, and achieved pipe run lengths of
62m, 52m, and 55m

Does this pipe layout seem OK? (excuse the dodgy grid, as it seems Google
Sketchup is incapable of grids)

http://img84.imageshack.us/my.php?im...elayoutsq2.jpg

There are a couple of small runs where the hots run next to each other on
adacent sections, which are hard to avoid. I am asuming this will not be
a big deal.

I really only have one question.

I am clipping the pipes down directly onto celotex foil backed insulation.
I have taped the joins between the foil boards with foil tape. The kit I
have, has edge insulation, and the insulation handbook says the following:

"IMPORTANT: if you are going to use a liquid screed you need to use an
expansion strip with a thin polythene strip attached to it. The polythene
strip must be taped to the membrane that has been laid on top of the
insualtion with specialist floor screed tape to ensure a watertight seal".

Now all that seem quite scary and implies it's important... I will be
using a sand/cement screed, but unsure if this is classed as a "liquid
screed".

So my question is, do I need to do any additional taping/waterproofing
with a sand/cement screed? Or can I just pin the pipes down to the
celotex, and lay the insulation strip around the permiter. Or do I need to
do special stuff.

I think that's all for the moment. Hopefully I have everything prepared,
and I can get most of the kit down this weekend (I might not get the
manifold in, as it's going under the floor in the living room, and it
means lifting floors..)

Any other tips and knowledgable folks here can help with???

Many thanks.

I used the Eco-hometec wet UFH system about 2 yrs ago - and it's still
working!

Unless they've changed their pipework, I'd say some of the angles in
your layout are unachievable. The pipe they used to supply (16mm IIRC)
is really quite stiff, and I don't think you'll get a radius any less
than 50cm.You *really* don't want to put a kink in it. Some of the
acute angles you have in your layout, are too sharp, I think.

Don't worry about tape etc. The clips will hold the pipe in place just
fine. And the screed will hold the edge insulation in place too. Just
make sure whoever does the screed for you doesn't remove it!

Alos, I'd plan to leave a bit of pipe left over. One of the most
stressful times in my project was when I was laying the pipework the
day before the guys were coming to lay the screed. Somehow I was 5m
short. Had to get some more sent by courier, which inevitably was
late. They started laying the screed, and the extra pipe and coupler
arrived just as they got to the bit I was working on.

Everyone says you should pressurise the system. I must admit, I filled
it, but didn't pressurise it. I really didn't see the point. The pipe
is *so* tough. You can stand on it, no problem. And 4 inches of
concrete just ain't that heavy. As you say, pressurising it is a pain.

when it's done though...lovely! :-)

Jon.

In your cae you should have, simply because it sounds like you committed
the cardinal sin of joining a pipe under the floor.

You should do your runs to the manifold carefully as a complete run of
pipe. If that means you have a load of 20m or so lengths left over, so
be it.

Pressurising may not be necessary, but if you have - say - a pinhole
leak in a pipe, its a small price to pay as against having to rip up all
the screed after its gone down..

On Feb 22, 8:55*am, Tournifreak wrote:

I used the Eco-hometec wet UFH system about 2 yrs ago - and it's still
working!

Unless they've changed their pipework, I'd say some of the angles in
your layout are unachievable. The pipe they used to supply (16mm IIRC)
is really quite stiff, and I don't think you'll get a radius any less
than 50cm.You *really* don't want to put a kink in it. Some of the
acute angles you have in your layout, are too sharp, I think.


Yep, I anticipate this, I was being lazy when I drew it out. The
handbook says 90cm radius I recall. I just means my runs are slightly
shorter than I planned. But I will work around this as I lay it.

Don't worry about tape etc. The clips will hold the pipe in place just
fine. And the screed will hold the edge insulation in place too. Just
make sure whoever does the screed for you doesn't remove it!

Alos, I'd plan to leave a bit of pipe left over. One of the most
stressful times in my project was when I was laying the pipework the
day before the guys were coming to lay the screed. Somehow I was 5m
short. Had to get some more sent by courier, which inevitably was
late. They started laying the screed, and the extra pipe and coupler
arrived just as they got to the bit I was working on.

Screeder is not booked yet, I am going to wait until it's down, and I
can afford it!!! :-)

Everyone says you should pressurise the system. I must admit, I filled
it, but didn't pressurise it. I really didn't see the point. The pipe
is *so* tough. You can stand on it, no problem. And 4 inches of
concrete just ain't that heavy. As you say, pressurising it is a pain.

I might invest in one of the screwfix jobbies, and then sell it on
afterwards, or have a poke around on ebay tonight....


when it's done though...lovely! :-)

Jon.


PS. I am posting from my Google Groups account, so I don't know what
my display name is, but I have already noticed by laptop and desktpp
PC have different usenet names// Black Shuck == Mark Gillespie ==
Whatever this comes out as!!!


Thanks to all for the advice. Wish me luck :-) I;m going in....

On Fri, 22 Feb 2008 09:41:20 +0000
The Natural Philosopher wrote:


Letting screed dry is a good idea, but its not necessary that its DRY,
its necessary that its fully set. 6-8 weeks is 'proper' but I think you
would get away with one in practice.

I'm not a concrete chemist, but my father (88) is. He says that the
full strength of the screed won't be developed until significant
crystallisation has taken place, and that takes some weeks. In fact
concrete keeps getting stronger for centuries!

OK, if you are only going to walk on the slab, or maybe spend a week
or so laying tile or stone or laminate, a week will be OK. But not to
put point-loads on it, chair legs for instance. It really depends on
what you plan to do next.

R.

On 22 Feb, 09:45, The Natural Philosopher wrote:
Tournifreak wrote:
On Feb 22, 12:03 am, "Mark Gillespie"
wrote:
This weekends project, is to fit underfloor heating into my conservatory
project. I bought a kit from a UK supplier (eco-hometech), and it seems
to have everything I need.

The conservatory area is 18.6sqM and the supplier recommened 3 pipe
sections from the manifold/pump. I have arranged my pipes in a
counterflow pattern, with 100mm centres, and achieved pipe run lengths of
62m, 52m, and 55m

Does this pipe layout seem OK? (excuse the dodgy grid, as it seems Google
Sketchup is incapable of grids)

http://img84.imageshack.us/my.php?im...elayoutsq2.jpg

There are a couple of small runs where the hots run next to each other on
adacent sections, which are hard to avoid. I am asuming this will not be
a big deal.

I really only have one question.

I am clipping the pipes down directly onto celotex foil backed insulation.
I have taped the joins between the foil boards with foil tape. The kit I
have, has edge insulation, and the insulation handbook says the following:

"IMPORTANT: if you are going to use a liquid screed you need to use an
expansion strip with a thin polythene strip attached to it. The polythene
strip must be taped to the membrane that has been laid on top of the
insualtion with specialist floor screed tape to ensure a watertight seal".

Now all that seem quite scary and implies it's important... I will be
using a sand/cement screed, but unsure if this is classed as a "liquid
screed".

So my question is, do I need to do any additional taping/waterproofing
with a sand/cement screed? Or can I just pin the pipes down to the
celotex, and lay the insulation strip around the permiter. Or do I need to
do special stuff.

I think that's all for the moment. Hopefully I have everything prepared,
and I can get most of the kit down this weekend (I might not get the
manifold in, as it's going under the floor in the living room, and it
means lifting floors..)

Any other tips and knowledgable folks here can help with???

Many thanks.

I used the Eco-hometec wet UFH system about 2 yrs ago - and it's still
working!

Unless they've changed their pipework, I'd say some of the angles in
your layout are unachievable. The pipe they used to supply (16mm IIRC)
is really quite stiff, and I don't think you'll get a radius any less
than 50cm.You *really* don't want to put a kink in it. Some of the
acute angles you have in your layout, are too sharp, I think.

Don't worry about tape etc. The clips will hold the pipe in place just
fine. And the screed will hold the edge insulation in place too. Just
make sure whoever does the screed for you doesn't remove it!

Alos, I'd plan to leave a bit of pipe left over. One of the most
stressful times in my project was when I was laying the pipework the
day before the guys were coming to lay the screed. Somehow I was 5m
short. Had to get some more sent by courier, which inevitably was
late. They started laying the screed, and the extra pipe and coupler
arrived just as they got to the bit I was working on.

Everyone says you should pressurise the system. I must admit, I filled
it, but didn't pressurise it. I really didn't see the point. The pipe
is *so* tough. You can stand on it, no problem. And 4 inches of
concrete just ain't that heavy. As you say, pressurising it is a pain.

when it's done though...lovely! :-)

Jon.

In your cae you should have, simply because it sounds like you committed
the cardinal sin of joining a pipe under the floor.

You should do your runs to the manifold carefully as a complete run of
pipe. If that means you have a load of 20m or so lengths left over, so
be it.

Pressurising may not be necessary, but if you have - say - a pinhole
leak in a pipe, its a small price to pay as against having to rip up all
the screed after its gone down..

Thinking back, I did do a quick leak test - pressurised that run for a
few minutes. The join I used was quite impressive. Not like anything
I've seen before. A sort of compression joint on steroids.

You're right - ideally I should have replaced the whole run. But the
screeders had already started laying screed over the other side of the
room! You live and learn I guess. Always buy a good length more pipe
than you calculate you'll need.

Jon.

TheOldFellow wrote:
On Fri, 22 Feb 2008 09:41:20 +0000
The Natural Philosopher wrote:


Letting screed dry is a good idea, but its not necessary that its
DRY, its necessary that its fully set. 6-8 weeks is 'proper' but I
think you would get away with one in practice.

I'm not a concrete chemist, but my father (88) is. He says that the
full strength of the screed won't be developed until significant
crystallisation has taken place, and that takes some weeks. In fact
concrete keeps getting stronger for centuries!

Someone told me that the reason the WW2 Pill Boxes that are scattered around
haven't been demolished, is that the 50 year old concrete is so tough & they
would be difficult to knock down.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

The message
from "The Medway Handyman" contains
these words:

I'm not a concrete chemist, but my father (88) is. He says that the
full strength of the screed won't be developed until significant
crystallisation has taken place, and that takes some weeks. In fact
concrete keeps getting stronger for centuries!

Someone told me that the reason the WW2 Pill Boxes that are scattered
around
haven't been demolished, is that the 50 year old concrete is so tough
& they
would be difficult to knock down.

I think it is a matter of cost. Reinforced concrete that may be several
feet thick takes time and a good deal of effort. When I was a child back
in the 50s there was a corner site on the sea front that was partly
occupied by a large concrete pill box where we used to play. A prime
site for housing so eventually the pill box was demolished.

A rather more questionable clean-up operation was the removal of a
series of concrete cube tank traps that used to line one side of a
school playing field. The concrete pill box across the way is still
there but with its entrance blocked up as are a few more tank traps that
weren't within the school perimeter.

Just in case anyone wants to know the locations the first pill box was
located on the corner of Beach Road and Lower Marine Parade, Dovercourt,
Essex and the demolished tank traps along the boundary between what is
now The Harwich School and Half Acre Lane. The second pill box and the
remaining tank traps are close to the junction between Half Acre Lane
and Squat Lane.

Nearby on the former Allfields allotments someone had a brick built pill
box in their garden but I cna't now locate it on Google Earth. Given
that my last sighting of this must have been while walking my dog some
10 years ago it could have since been demolished or it could be
conpletely shaded by trees.

--
Roger Chapman

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Mark Gillespie"
saying something like:

Does this pipe layout seem OK? (excuse the dodgy grid, as it seems Google
Sketchup is incapable of grids)

http://img84.imageshack.us/my.php?im...elayoutsq2.jpg

Fine, allowing for the limitations of the etch-a-sketch google app.
There's on thing I would change and that's the rightmost loop. Reverse
it, so the hot goes along the outside wall first and then continues
inwards. The other two loops are fine that way.
--

Dave

Grimly Curmudgeon wrote:

Fine, allowing for the limitations of the etch-a-sketch google app.
There's on thing I would change and that's the rightmost loop. Reverse
it, so the hot goes along the outside wall first and then continues
inwards. The other two loops are fine that way.

I'm very puzzled by this, and since none of the plumbers here have
complained, it must be me.

The first thing all of the circuits do is to run a hot feed next to a
cold return, and for a good long length.

If I was designing a system to transfer heat between two fluids, that's
exactly what I'd do. It looks like a great way of transferring heat
from the incoming hot to the outgoing cold. As this is obviously not
the intent of the system, why doesn't this happen?

Andy