https://docs.google.com/drawings/d/1...it?usp=sharing

That's my shower room plan and cross section through floor.

I am wondering whether to connect the UFH or not.

Looking at how it's gone together, I'm concerned that we've let things
slip though lack of control of the process and effectively both drains
are coupled to the screed and/or finish tiles.

If we run UFH at 40C and assuming a 10C starting point, the thermal
coefficient of expansion of screed is around 0.02mm per m per C -

end result, the screed will expand by about 1-2 mm depending on
direction over the full heating cycle.

That's going to try to bend both drain pipes (110 PVC soil pipes) over a
height of 50mm so at worst a 1:25 shear (they can flex in the celotex
layer).



So I'm wondering if that presents a risk of cracking or weakening the pipes?

Low risk, high impact scenario (the type of scenario I really don't do
well with!). Breaking either one of those drains will be a disaster - we
lose drainage to one or both bathrooms, boiler and kitchen. Fixing means
digging it up.

What do you reckon? Anyone with experience of building UFH into a bathroom?

Losing the UFH will not be a disaster - more of a nice to have.


Cheers - Tim


How did we get he

Despite best efforts putting foam around the screed perimeter and one
drain pipe (the other got overlooked) we've also ended up with the tiles
grouted in hard around Drain 1. The tiles stop short of Drain 2 as it's
a mess of pipes and will be in the under basin cupboard anyway.

If I was laying the tiles, I would have probably noticed and stopped and
left room to silicone. However, this type of tiling exceeds my ability
and when you have a tiler whacking them down at full speed, details are
hard to manage...

(This was a "chance" UFH zone - we really wanted it for the
conservatory, but for other reasons we had to did this 3m2 section of
floor out so we chucked some spare pipe in on the offchance).

On 29/10/17 10:23, Tim Watts wrote:
https://docs.google.com/drawings/d/1...it?usp=sharing


That's my shower room plan and cross section through floor.

I am wondering whether to connect the UFH or not.

Looking at how it's gone together, I'm concerned that we've let things
slip though lack of control of the process and effectively both drains
are coupled to the screed and/or finish tiles.

If we run UFH at 40C and assuming a 10C starting point, the thermal
coefficient of expansion of screed is around 0.02mm per m per C -

end result, the screed will expand by about 1-2 mm depending on
direction over the full heating cycle.

That's going to try to bend both drain pipes (110 PVC soil pipes) over a
height of 50mm so at worst a 1:25 shear (they can flex in the celotex
layer).



dont worry. Just whack in hot water. 50C would be good.

Concrete will simply stress up rather than expand


--
Any fool can believe in principles - and most of them do!

On 29/10/17 11:09, The Natural Philosopher wrote:
On 29/10/17 10:23, Tim Watts wrote:
https://docs.google.com/drawings/d/1...it?usp=sharing


That's my shower room plan and cross section through floor.

I am wondering whether to connect the UFH or not.

Looking at how it's gone together, I'm concerned that we've let things
slip though lack of control of the process and effectively both drains
are coupled to the screed and/or finish tiles.

If we run UFH at 40C and assuming a 10C starting point, the thermal
coefficient of expansion of screed is around 0.02mm per m per C -

end result, the screed will expand by about 1-2 mm depending on
direction over the full heating cycle.


That's going to try to bend both drain pipes (110 PVC soil pipes) over
a height of 50mm so at worst a 1:25 shear (they can flex in the
celotex layer).



dont worry. Just whack in hot water. 50C would be good.

Concrete will simply stress up rather than expand



A relative has Underfloor Heating, a water system, in a number of rooms.
I confess I was 'dubious', as a teenager (in the 70s) I lived in a house
(well flat) with u/f electric heating. The only time is was actually
warm was when it was broken- the thermostat and the timer (it was
supposed to work on 'cheap' electricity (I'm not sure if it was called
Economy 7 back then). The block of flats was new when we moved in and
several, if not all, of the flats had the same, or similar, faults. The
new tenants thought it was great at first- most had moved (as we had)
from homes with no real central heating- just a coal fire and a couple
of radiators in two or three rooms 'powered' from it (this was in the
North East, so the winters were cold!).

When the electric bills arrived, there was hell to pay. The systems were
fixed and the flats were never really warm.

However, the system in my relatives house seems very effective.
Certainly the bathrooms etc in particular are very 'comfortable'.

I'm not sure about running costs, the relative's house is a lot larger
than most- larger than ours which isn't small. His 'boiler' is more
like something you would see in a small industrial unit.

On 29/10/17 11:41, Brian Reay wrote:
On 29/10/17 11:09, The Natural Philosopher wrote:


I'm not sure about running costs, the relative's house is a lot larger
than most-Â* larger than ours which isn't small. His 'boiler' is more
like something you would see in a small industrial unit.



I was heatinhg 2000 sq ft on a 12Kw boiler.

UFH is just a big radiator laid on its side...
what counts is insulation.

Heatloss from the hot floor to the cold ground can be very high unless
you have a lot of insulation under.

The other key issue is to have a lot of pipes in the floor, epecially if
the floor is covered in rugs and furniture.






--
€œit should be clear by now to everyone that activist environmentalism
(or environmental activism) is becoming a general ideology about humans,
about their freedom, about the relationship between the individual and
the state, and about the manipulation of people under the guise of a
'noble' idea. It is not an honest pursuit of 'sustainable development,'
a matter of elementary environmental protection, or a search for
rational mechanisms designed to achieve a healthy environment. Yet
things do occur that make you shake your head and remind yourself that
you live neither in Joseph Stalins Communist era, nor in the Orwellian
utopia of 1984.€�

Vaclav Klaus

On 29/10/2017 10:23, Tim Watts wrote:
https://docs.google.com/drawings/d/1...it?usp=sharing


That's my shower room plan and cross section through floor.

I am wondering whether to connect the UFH or not.

Looking at how it's gone together, I'm concerned that we've let things
slip though lack of control of the process and effectively both drains
are coupled to the screed and/or finish tiles.

If we run UFH at 40C and assuming a 10C starting point, the thermal
coefficient of expansion of screed is around 0.02mm per m per C -

end result, the screed will expand by about 1-2 mm depending on
direction over the full heating cycle.

That's going to try to bend both drain pipes (110 PVC soil pipes) over a
height of 50mm so at worst a 1:25 shear (they can flex in the celotex
layer).

In the case of pipe 1, its retained at the tile interfqace, but then
free to move through both the screen and the celotex, so you are
spreading that movement out over 125mm of pipe. Can't see that being an
issue. Also most movement will occur when the system is at an elevated
temperatures (if we assume it wall all built in the "cold" state). So
the pipe itself will be at its most plastic when subjected to any movement.

Pipe two looks like it is somewhat protected from longer runs of screed
etc by the notch in the screed, and the squint on the wall to its left.
So its at worst only really exposed to the expansion over the short axis
of the room (and half that will be toward the other wall)


So I'm wondering if that presents a risk of cracking or weakening the
pipes?

PVC 110mm soil pipe? Can't see there being any risk really - the stuff
is very robust... it would survive much higher stresses in a situation
where its buried, and the ground moves or subsides.

Low risk, high impact scenario (the type of scenario I really don't do
well with!). Breaking either one of those drains will be a disaster - we
lose drainage to one or both bathrooms, boiler and kitchen. Fixing means
digging it up.

What do you reckon? Anyone with experience of building UFH into a bathroom?

Over worrying on this one I think.


--
Cheers,

John.

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

On 29/10/17 12:48, John Rumm wrote:
On 29/10/2017 10:23, Tim Watts wrote:
https://docs.google.com/drawings/d/1...it?usp=sharing





In the case of pipe 1, its retained at the tile interfqace, but then
free to move through both the screen and the celotex, so you are
spreading that movement out over 125mm of pipe. Can't see that being an
issue. Also most movement will occur when the system is at an elevated
temperatures (if we assume it wall all built in the "cold" state). So
the pipe itself will be at its most plastic when subjected to any movement.

Good point - overlooked that...

Pipe two looks like it is somewhat protected from longer runs of screed
etc by the notch in the screed, and the squint on the wall to its left.
So its at worst only really exposed to the expansion over the short axis
of the room (and half that will be toward the other wall)


So I'm wondering if that presents a risk of cracking or weakening the
pipes?

PVC 110mm soil pipe? Can't see there being any risk really - the stuff
is very robust... it would survive much higher stresses in a situation
where its buried, and the ground moves or subsides.

Yes, I guess.


Low risk, high impact scenario (the type of scenario I really don't do
well with!). Breaking either one of those drains will be a disaster - we
lose drainage to one or both bathrooms, boiler and kitchen. Fixing means
digging it up.

What do you reckon? Anyone with experience of building UFH into a
bathroom?

Over worrying on this one I think.

As usual... That's why I come here I'm short of friends in real life
who have much of a clue about DIY stuff, especially specialist complex
stuff like this (though I have at least met you and Adam in person

You guys will have to come over when it's all done - been a long haul,
along with the rest of life, but it's looking good.

Can't wait to start landscaping the garden!



Probably the thing to do here is to power it up at a low temperature and
see if there is any perceivable movement (feeler gauge down the
wall/tile gaps or something.

On 29/10/2017 13:08, Tim Watts wrote:
On 29/10/17 12:48, John Rumm wrote:

What do you reckon? Anyone with experience of building UFH into a
bathroom?

Over worrying on this one I think.

As usual... That's why I come here I'm short of friends in real life
who have much of a clue about DIY stuff, especially specialist complex
stuff like this (though I have at least met you and Adam in person

You guys will have to come over when it's all done - been a long haul,
along with the rest of life, but it's looking good.

Yup it would be nice to see the end result - there was lots of work
there waiting to be done last time!

Can't wait to start landscaping the garden!

Shovel, or lots of man tools?

Probably the thing to do here is to power it up at a low temperature and
see if there is any perceivable movement (feeler gauge down the
wall/tile gaps or something.

Its good to run it up to full temp over some weeks anyway - gives
everything time to really dry out. (some boilers even have programs for
screed drying)


--
Cheers,

John.

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

In message , Tim Watts
writes
On 29/10/17 12:48, John Rumm wrote:
On 29/10/2017 10:23, Tim Watts wrote:

https://docs.google.com/drawings/d/1...BNZ31TcDI6KGA3
Z99rgeJqs/edit?usp=sharing



In the case of pipe 1, its retained at the tile interfqace, but then
free to move through both the screen and the celotex, so you are
spreading that movement out over 125mm of pipe. Can't see that being
an issue. Also most movement will occur when the system is at an
elevated temperatures (if we assume it wall all built in the "cold"
state). So the pipe itself will be at its most plastic when subjected
to any movement.

Good point - overlooked that...

Pipe two looks like it is somewhat protected from longer runs of
screed etc by the notch in the screed, and the squint on the wall to
its left. So its at worst only really exposed to the expansion over
the short axis of the room (and half that will be toward the other wall)

So I'm wondering if that presents a risk of cracking or weakening
the
pipes?
PVC 110mm soil pipe? Can't see there being any risk really - the
stuff is very robust... it would survive much higher stresses in a
situation where its buried, and the ground moves or subsides.

Yes, I guess.


Low risk, high impact scenario (the type of scenario I really don't

well with!). Breaking either one of those drains will be a disaster - we
lose drainage to one or both bathrooms, boiler and kitchen. Fixing means
digging it up.

What do you reckon? Anyone with experience of building UFH into a
bathroom?
Over worrying on this one I think.

As usual... That's why I come here I'm short of friends in real life
who have much of a clue about DIY stuff, especially specialist complex
stuff like this (though I have at least met you and Adam in person

You guys will have to come over when it's all done - been a long haul,
along with the rest of life, but it's looking good.

Can't wait to start landscaping the garden!



Probably the thing to do here is to power it up at a low temperature
and see if there is any perceivable movement (feeler gauge down the
wall/tile gaps or something.

I think you are over stressing on this:-)

If you look at the max allowed working temperature for vinyl flooring
(27 deg. C) and accept that this is going to successfully heat your
room, the potential inlet water temperature of 40-50C is not going to be
reached by any part of the floor or nearby piping.

--
Tim Lamb

On 30/10/17 09:07, Tim Lamb wrote:
In message , Tim Watts
writes
On 29/10/17 12:48, John Rumm wrote:
On 29/10/2017 10:23, Tim Watts wrote:

https://docs.google.com/drawings/d/1...BNZ31TcDI6KGA3
Z99rgeJqs/edit?usp=sharing



Â*In the case of pipe 1, its retained at the tile interfqace, but then
free to move through both the screen and the celotex, so you are
spreading that movement out over 125mm of pipe. Can't see that being
anÂ* issue. Also most movement will occur when the system is at an
elevatedÂ* temperatures (if we assume it wall all built in the "cold"
state). SoÂ* the pipe itself will be at its most plastic when
subjected to any movement.

Good point - overlooked that...

Pipe two looks like it is somewhat protected from longer runs of
screedÂ* etc by the notch in the screed, and the squint on the wall to
its left.Â* So its at worst only really exposed to the expansion over
the short axisÂ* of the room (and half that will be toward the other
wall)

So I'm wondering if that presents a risk of cracking or weakening the
pipes?
Â*PVC 110mm soil pipe? Can't see there being any risk really - the
stuffÂ* is very robust... it would survive much higher stresses in a
situationÂ* where its buried, and the ground moves or subsides.

Yes, I guess.


Low risk, high impact scenario (the type of scenario I really don't
well with!). Breaking either one of those drains will be a disaster
- we
lose drainage to one or both bathrooms, boiler and kitchen. Fixing
means
digging it up.

What do you reckon? Anyone with experience of building UFH into a
bathroom?
Â*Over worrying on this one I think.

As usual... That's why I come here I'm short of friends in real
life who have much of a clue about DIY stuff, especially specialist
complex stuff like this (though I have at least met you and Adam in
person

You guys will have to come over when it's all done - been a long haul,
along with the rest of life, but it's looking good.

Can't wait to start landscaping the garden!



Probably the thing to do here is to power it up at a low temperature
and see if there is any perceivable movement (feeler gauge down the
wall/tile gaps or something.

I think you are over stressing on this:-)

If you look at the max allowed working temperature for vinyl flooring
(27 deg. C) and accept that this is going to successfully heat your
room, the potential inlet water temperature of 40-50C is not going to be
reached by any part of the floor or nearby piping.

Unless you cover it with a duvet...



--
"It is an established fact to 97% confidence limits that left wing
conspirators see right wing conspiracies everywhere"

On Monday, 30 October 2017 10:10:54 UTC, The Natural Philosopher wrote:
If you look at the max allowed working temperature for vinyl flooring
(27 deg. C) and accept that this is going to successfully heat your
room, the potential inlet water temperature of 40-50C is not going to be
reached by any part of the floor or nearby piping.
Unless you cover it with a duvet...

I can envisage localised depressions caused by sleeping cat.

Owain

On 30/10/17 10:16, wrote:
On Monday, 30 October 2017 10:10:54 UTC, The Natural Philosopher wrote:
If you look at the max allowed working temperature for vinyl flooring
(27 deg. C) and accept that this is going to successfully heat your
room, the potential inlet water temperature of 40-50C is not going to be
reached by any part of the floor or nearby piping.
Unless you cover it with a duvet...

I can envisage localised depressions caused by sleeping cat.

Owain


pets will grovel at your feet for good UFH


--
Microsoft : the best reason to go to Linux that ever existed.