Worrying noises from loft conversion

[Bert Coules]

A few years ago I had a (timber framed) loft conversion added to my
sixties semi-detached bungalow. The ceiling above the rear of the
bungalow was completely rebuilt to become also the floor of the major
part of the new loft room: timber joists, wet underfloor heating,
chipboard top layer, carpet.

For the past month or so I've been hearing worrying sounds coming from
this ceiling: sharp cracks, some of which are startlingly loud. They
don't appear to emanate from any particular part of the ceiling and
sometimes they occur in clusters with each individual sound from a
different place. They don't seem to be triggered by any particular
circumstances, just occurring at random.

There's been no cracking of the plastered ceiling and as far as I can
see, no movement of any of the structure, either in the lower room or
the loft extension. But the noises persist. What could be causing them?
Could it be the underfloor heating? And whatever the cause, what should
I do about it? Any thoughts would be very welcome. Thanks.

[Jack Harry Teesdale]

I would get a building surveyor to take a look at it, it doesn't sound good.

[alan_m]

On 28/01/2023 00:48, Bert Coules wrote:

>

> There's been no cracking of the plastered ceiling and as far as I can
> see, no movement of any of the structure, either in the lower room or
> the loft extension. But the noises persist. What could be causing them?
> Could it be the underfloor heating? And whatever the cause, what should
> I do about it? Any thoughts would be very welcome. Thanks.

If it was central heating piping wouldn't it be triggered by the delayed
timing of your ch controller?


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

[Theo]

It could be thermal expansion: if there's a change in temperature, two solid
things may have to move past each other to relieve expansion stress - that
would cause a nano-earthquake as all the stress is relieved at once,
resulting in a snap noise.

Typically this is the cause of pipes creaking when the heating turns on, but
it could cause timber-on-timber noises too. With UFH, presumably the entire
floor is a central heating pipe, and it could move with respect to the timber
structure it sits upon.

I would experiment with the heating controls: what happens if you turn off
the UFH completely for a day or two - does it change the frequency of the
noises?

Other possibilities: wind loading, structural stresses, failing fixings
(nails etc), water leakage...

Theo

[Davey]

On 28 Jan 2023 10:56:00 +0000 (GMT)

..imminent collapse....
--
Davey.

[Spike]

Just a thought, but we’ve had some cold North winds recently that have
brought low humidity Arctic air. In these circumstances wood can begin to
dry out, and make creaking, etc noises. Unfortunately, when normal humidity
returns, the process, with noises, is reversed. Our dining-room table seems
quite sensitive to this cycle.

--
Spike

[Tim Lamb]

In message <tr2tm4$2688k$1...@dont-email.me>, Jack Harry Teesdale
<noreply49...@yahoo.co.uk> writes

What temperature is the underfloor water? Most designs limit this to
50deg. C but yours may be branched off an existing radiator
installation.

--
Tim Lamb

[The Natural Philosopher]

On 28/01/2023 00:48, Bert Coules wrote:

I had such over the long hot summer, and I think one part of the house
may have subsided about 3mm due to clay shrinkage. After 20 years! one
bathroom door doesn't close right and a slight split in nearby tiles has
appeared.
The cracks are movement of one piece of wood against another.

Its possible that you have very slight structural shifting, or perhaps
wood shrinkage due to the low RH inside buildings at this time of year.

Unless you see visible signs of major movement, ignore it

--
If you tell a lie big enough and keep repeating it, people will
eventually come to believe it. The lie can be maintained only for such
time as the State can shield the people from the political, economic
and/or military consequences of the lie. It thus becomes vitally
important for the State to use all of its powers to repress dissent, for
the truth is the mortal enemy of the lie, and thus by extension, the
truth is the greatest enemy of the State.

Joseph Goebbels

[The Natural Philosopher]

Yes, for the first time in a year, one of my garden doors actually opens
and closes freely.

--
“Politics is the art of looking for trouble, finding it everywhere,
diagnosing it incorrectly and applying the wrong remedies.”
― Groucho Marx

[Brian Gaff]

I suspect something is drying out and warping, so it may be OK now but if it
gets worse then something structural may well come loose, assuming no rot
oof course There is another thought, Could here be a tiny leak in the
heating pips, as this could very quickly dampen timbers and they can rot.
This happened to my late uncle in Leads inside an enclosure round some pipes
running to the upstairs. He even had fungus inside when the panels were
removed.
Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
bri...@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Jack Harry Teesdale" <noreply49...@yahoo.co.uk> wrote in message
news:tr2tm4$2688k$1...@dont-email.me...

[Bert Coules]

Many thanks to everyone for the thoughts and suggestions.

Since the sounds have now been going on for eight weeks or so, and given
that there's no sign of any movement or cracking, I'd like to think
that, whatever's happening, it doesn't indicate a serious structural
problem. But of course I could be wrong.

To examine the timber structure of the floor would mean either lifting
the upstairs carpet, chipboard, and whatever the heating pipes are laid
in (or I suppose they could be clipped to the joists?) or removing the
downstairs ceiling. Either way it would be a pretty disruptive job.

There are no radiators, either upstairs or down, and in both zones the
wall thermostats are set at 24 degrees. I'll try turning the upstairs
one right down and see if that makes any difference.

[Jeff Gaines]

On 28/01/2023 in message

<hfCcnc4m4ZeOukj-...@brightview.co.uk> Bert Coules wrote:

>in both zones the wall thermostats are set at 24 degrees

Wow there's a young Swedish activist on her way to beat you over the head.
Do you realise your are ruining her childhood :-)

--
Jeff Gaines Dorset UK
I've been through the desert on a horse with no name.
It was a right bugger to get him back when he ran off.

[Bert Coules]

On 28/01/2023 14:14, Jeff Gaines wrote:

> Wow there's a young Swedish activist on her way to beat you over the
> head. Do you realise your are ruining her childhood :-)

Not that I care in the slightest, but what setting do you think she
would suggest?

[Jeff Gaines]

On 28/01/2023 in message

10 in the day and 5 at night :-)

--
Jeff Gaines Dorset UK

Though no-one can go back and make a new start, everyone can start from
now and make a new ending.

[Bert Coules]

On 28/01/2023 13:10, Brian Gaff wrote:
> Could here be a tiny leak in the

> heating pipes, as this could very quickly dampen timbers and they can rot.

Brian, thanks for the thought. There's been no indication of a leak,
though I suppose a very small one might not noticeably affect the
pressure indicator on the boiler.

Unfortunately I don't know enough about UFH to know how to check for a leak

[Bert Coules]

On 28/01/2023 13:09, The Natural Philosopher wrote:

> Unless you see visible signs of major movement, ignore it.

At its worse the sound is rather too loud to ignore, I'm afraid.

[Bert Coules]

On 28/01/2023 14:40, Jeff Gaines wrote:

> 10 in the day and 5 at night :-)

Hm. Some advice is perhaps best ignored.

[Nick Odell]

I only mean this semi-frivolously but: are you absolutely sure that
your delightful next-door neighbours (uk.d-i-y passim) have nothing to
do with this?

Nick

[Tim Lamb]

In message <hfCcnc4m4ZeOukj-...@brightview.co.uk>, Bert
Coules <ma...@bertcoules.co.uk> writes

Oh. I assumed that the loft conversion heating would be an addition to
existing rather than a whole house upgrade.

I installed three different wet underfloor systems here. For solid
floors, expanded polystyrene panels with shallow slots for the pipes
each having Aluminium foil thermal spreaders. Thin foam sheet to allow
movement and then conventional chipboard flooring with very careful nail
positioning!

Screeded floor had the pipes clipped to the foam insulation prior to
screed laying.

Suspended floor had 18mm pre grooved chipboard laid across the joists
with Aluminium grooved spreaders laid in prior to pipe fitting. Foam
sheet and chip floor as above.

Two multiway manifolds and circulation pumps controlled by individual
roomstats allow local control.

Design pipe spacing and relatively low water temperature (50 C max) make
the system slow to respond but fine for geriatric 24 hour occupation.

I can't remember where the idea/need for the 3mm foam isolator came from
but retrofit would have been horrendous:-(
>

--
Tim Lamb

[Jeff Gaines]

On 28/01/2023 in message

Absolutely, although she may offer to keep you warm at night since I
suspect she lacks opportunities in that area.

My programmable hall stat is set at 21 in the day and 16 overnight.

--
Jeff Gaines Dorset UK

Here we go it's getting close, now it's just who wants it most.

[Bert Coules]

On 28/01/2023 14:48, Nick Odell wrote:

> I only mean this semi-frivolously but: are you absolutely sure that
> your delightful next-door neighbours (uk.d-i-y passim) have nothing to
> do with this?

Nick, what a memory you have. The possibility hadn't even occurred to
me, largely because (I'm pleased to be able to tell you) all conflict
and unpleasentness is now a thing of the past, and cordial relations
have been resumed.

Don't ask me how it came about because I don't know: it just happened
one day, with no action whatsoever on my part: Next Door initiated a
most cordial conversation over the garden fence, culminating a handshake.

So no, the cause lies elsewhere...

[Tim+]

24? That just willy waving that is. ;-)

Tim

--
Please don't feed the trolls

[Bert Coules]

On 28/01/2023 15:00, Tim Lamb wrote:

> Oh. I assumed that the loft conversion heating would be an addition to
> existing rather than a whole house upgrade.

Sorry, I should have made that clear. Yes, the work done was extensive
and involves, among other things, the removal of all the existing
ceilings and old radiator-based heating.

> Design pipe spacing and relatively low water temperature (50 C max) make
> the system slow to respond but fine for geriatric 24 hour occupation.

According to the rotary thermostat valves situated close to the
manifolds, the upstairs system is set to 45 degrees, the downstairs 50.

Since turning the upstairs wall stat very low (16 degrees) there's been
no repetition of the cracking sounds. But whether this is a permanent
state of affairs remains to be seen, and even if it is, I don't know if
the resultant temperature once the space cools down will be comfortable.
"Geriatric 24 hour occupation describes the situation here perfectly,
I'm afraid.

[Tim+]

At 16 degrees it will not be comfortable! Try 20, and if that’s too cool
for you, 21.

[Spike]

The Natural Philosopher <t...@invalid.invalid> wrote:

> I had such over the long hot summer, and I think one part of the house
> may have subsided about 3mm due to clay shrinkage. After 20 years! one
> bathroom door doesn't close right and a slight split in nearby tiles has
> appeared.

My previous house was built on clay subsoil, and to prevent this kind of
thing I used to water the foundations from late spring to early autumn,
along with the garden plants.

I also used to water the (1.8m) garden wall foundations, much to the
amusement of one of my neighbours. Until his wall fell over…

Was on ‘rateable value’ water in those days, though.


--
Spike

[ARW]

That made me smile.

[Nick Odell]

I'm delighted to learn that peace has broken out across the garden
fence. Disagreements with neighbours are such a drain on energy,
happiness and contentment (DAMHIKT)

I hope you find the source of this problem soon.

Nick

[Mark Carver]

On 28/01/2023 00:48, Bert Coules wrote:
> A few years ago I had a (timber framed) loft conversion added to my
> sixties semi-detached bungalow. The ceiling above the rear of the
> bungalow was completely rebuilt to become also the floor of the major
> part of the new loft room: timber joists, wet underfloor heating,
> chipboard top layer, carpet.

We had a new roof on our bungalow three years ago. For the first few
months (Summer 2020) there were random 'crack' sounds. They all settled
down, and stopped.
However they started again when we had the December 2022 cold snap.

No sign of cracks in any ceilings or walls. They seem to happen when the
CH is turned on, and after it turns off.

Haven't had any for a few days now, and of course the weather has warmed
up.....

I remember a few years ago we stayed in a large wooden house in Canada,
that was about 10 years old. There were no end of bangs and cracks all
the time.
The owner said they made her jump at first, but after a while she didn't
notice them.

[The Natural Philosopher]

-5°C

--
"The most difficult subjects can be explained to the most slow witted
man if he has not formed any idea of them already; but the simplest
thing cannot be made clear to the most intelligent man if he is firmly
persuaded that he knows already, without a shadow of doubt, what is laid
before him."

- Leo Tolstoy

[The Natural Philosopher]

Well if you have CH pipes in contact with joists, thermal expasnion can
cause them to slip.

[Bert Coules]

On 28/01/2023 17:14, Mark Carver wrote:

> We had a new roof on our bungalow three years ago. For the first few
> months (Summer 2020) there were random 'crack' sounds. They all settled
> down, and stopped.
> However they started again when we had the December 2022 cold snap.

Thanks for that. In my case the noises started for the time some three
years after the work was completed, though the cause could still be
same, I imagine.

[Bert Coules]

On 28/01/2023 17:09, Nick Odell wrote:

> I'm delighted to learn that peace has broken out across the garden
> fence. Disagreements with neighbours are such a drain on energy,
> happiness and contentment (DAMHIKT)

My word, I can certainly agree with you on that.

> I hope you find the source of this problem soon.

Thanks, Nick.

[Bert Coules]

On 28/01/2023 16:13, Tim+ wrote:

> At 16 degrees it will not be comfortable! Try 20, and if that’s too cool
> for you, 21.

The upstairs wall stat is currently (6:43pm) registering 23.5: the area
does benefit greatly from the heat of downstairs, and the new roof and
walls, being new, are extremely well insulated. The situation tomorrow
should reflect the change of setting more accurately.

[Bert Coules]

On 28/01/2023 15:23, Jeff Gaines wrote:

> Absolutely, although she may offer to keep you warm at night...

Surely, given the stance that it's global warming that's the real
problem, she'd be more likely to suggest a way of doing the exact opposite?

Either way, and meaning no offence to the lady, I believe I'd politely
decline.

Thanks for giving your thermostat settings.

[Bert Coules]

On 28/01/2023 18:33, Bert Coules wrote:

> In my case the noises started for the time some three

> years after the work was completed...

Damnation. For the *first* time, I meant. Apologies.

[Animal]

Take vitamin B tablets and halve your bills.

[jim.gm4dhj]

that's ok us Sherlocks figured that out....tee hee

[Bert Coules]

On 29/01/2023 10:29, jim.gm4dhj wrote:

> that's ok us Sherlocks figured that out....tee hee

Ha! Nice one. Thanks.

[The Natural Philosopher]

I run downstairs at 19°C and dint have any regular heating upstairs
except where I work.

This is generally OK for general living, and if I want more I can light
a fire.

--
The biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations
into what the world ought to be, whilst we fail utterly to deal with
what it actually is.

[Bert Coules]

On 29/01/2023 10:47, The Natural Philosopher wrote:

> I run downstairs at 19°C and dint have any regular heating upstairs
> except where I work.

Perhaps it's because the whole ground floor of my house (with the
exception of a small bathroom) is completely open plan, or perhaps it's
just me, but I find that in cold weather any setting below 24C is very
uncomfortable. And even at 24C I frequently have to boost things with a
separate fire.

[Tim Lamb]

In message <qqecnRqY38zGxUv-...@brightview.co.uk>, Bert
Coules <ma...@bertcoules.co.uk> writes

Underfloor heating is *laggy* in that it has to re-heat the thermal mass
of your floor material before adding anything to the air temperature.
With the current energy cost concerns, most of our room stats are 18C or
lower. The warmest places are the airing and cloaks cupboards where the
heating manifolds live!

--
Tim Lamb

[The Natural Philosopher]

On 29/01/2023 11:28, Bert Coules wrote:
> On 29/01/2023 10:47, The Natural Philosopher wrote:
>
>> I run downstairs at 19°C and dint have any regular heating upstairs
>> except where I work.
>
> Perhaps it's because the whole ground floor of my house (with the
> exception of a small bathroom) is completely open plan,

So is mine largely.

> or perhaps it's
> just me, but I find that in cold weather any setting below 24C is very
> uncomfortable.  And even at 24C I frequently have to boost things with a
> separate fire.

You have a health problem.
I am comfortable with just a T-shirt and jeans on at 21°C.

--
"First, find out who are the people you can not criticise. They are your
oppressors."
- George Orwell

[RJH]

Good grief. Rarely above 18C here. 15C in the day is fine.

Temperature tolerance is a strange thing given we're (mostly) the same species
in the same UK climate.

Apparently as we get older we're less able to feel cold, yet more susceptible
to its ill effects.
--
Cheers, Rob, Sheffield UK

[The Natural Philosopher]

We lose sensation, but we are so much lower at a metabolic rate that we
actually get colder.

My late mother ended up in hospital (fell and broke her hip), where she
complained of 'being cold'. I asked why?, and the doctor said' because
she *is* cold, and we are not sure why'.

At home she had been running the CH very hot.

I think she was put on thyroid pills for an underactive thyroid. Not
uncommon in older people.

It might be a way to save on heating bills - Take Thyroxin!


--
The theory of Communism may be summed up in one sentence: Abolish all
private property.

Karl Marx

[SteveW]

On 29/01/2023 12:57, The Natural Philosopher wrote:
> On 29/01/2023 11:28, Bert Coules wrote:
>> On 29/01/2023 10:47, The Natural Philosopher wrote:
>>
>>> I run downstairs at 19°C and dint have any regular heating upstairs
>>> except where I work.
>>
>> Perhaps it's because the whole ground floor of my house (with the
>> exception of a small bathroom) is completely open plan,
>
> So is mine largely.
>
>  > or perhaps it's
>> just me, but I find that in cold weather any setting below 24C is very
>> uncomfortable.  And even at 24C I frequently have to boost things with
>> a separate fire.
>
> You have a health problem.
> I am comfortable with just a T-shirt and jeans on at 21°C.

I agree. Our living room is set at 20°C. When I an WFH, I am sat in it,
in jeans and tee-shirt, no shoes and no socks, with laminate flooring.
As my WFH days keep changing, the timer is not set for those days and so
I tend to turn the heating back on (each room is independent) when it
drops to below 18°C (assuming that I have noticed that it is cold by then).

[Bert Coules]

On 29/01/2023 12:57, The Natural Philosopher wrote:

> You have a health problem.

Possibly so.

> I am comfortable with just a T-shirt and jeans on at 21°C.

In which case I envy you.

[Rod Speed]

On Sun, 29 Jan 2023 23:57:30 +1100, The Natural Philosopher
<t...@invalid.invalid> wrote:

> On 29/01/2023 11:28, Bert Coules wrote:
>> On 29/01/2023 10:47, The Natural Philosopher wrote:
>>
>>> I run downstairs at 19°C and dint have any regular heating upstairs
>>> except where I work.
>> Perhaps it's because the whole ground floor of my house (with the
>> exception of a small bathroom) is completely open plan,
>
> So is mine largely.
>
> > or perhaps it's
>> just me, but I find that in cold weather any setting below 24C is very
>> uncomfortable. And even at 24C I frequently have to boost things with
>> a separate fire.
>
> You have a health problem.

Nope, just different preferences.

> I am comfortable with just a T-shirt and jeans on at 21°C.

I'm not and never have been.

[Bert Coules]

On 29/01/2023 17:31, Rod Speed wrote:

>> You have a health problem. > > Nope, just different preferences.

Thank you.

[Peeler]

On Mon, 30 Jan 2023 04:31:37 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

<FLUSH the abnormal trolling senile cretin's latest trollshit unread>

--
Norman Wells addressing trolling senile Rodent:
"Ah, the voice of scum speaks."
MID: <g4t0jt...@mid.individual.net>

[The Natural Philosopher]

Bert, don't trust me, go and get your thyroid tested. If one pill a day
makes you feel warm again, its cheaper than burning oil or gas.

Seriously, 24°C, if genuine, is right at the limits of 'normal'.

[The Natural Philosopher]

Why should you be happy with that?

If you genuinely have a health problem, all that will do is make you in
denial of it, which is dangerous.

Particularly since an underactive thyroid is very easily fixed.

[Bert Coules]

An update: with the upstairs wall thermostat turned down to 16C and the
UFH thus effectively switched off, the cracking noises seemed to have
stopped altogether, but then there was an isolated couple of them (not
as loud as the worst of before) quite late in the evening. I couldn't
see or discover any specific triggering cause.

The temperature in the two rooms in the loft conversion dropped as
expected, stabilising around 21C thanks to the heat from downstairs.
This was just about tolerable for the bedroom but definitely not so for
the bathroom, which unfortunately wasn't given a separate zone of its own.

This evening I returned the stat to 23C and it wasn't too long before
the noises returned, almost exactly as before. I don't know if I'm
conveying just how loud and startling they can be: I'd record them and
post an audio file but without a reference level I'm not convinced it
would mean anything.

So, the experiment established that it's the heating which is causing
the problem; now I have to decide what to do about it.

[Peeler]

On Mon, 30 Jan 2023 04:31:37 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

<FLUSH the abnormal trolling senile cretin's latest trollshit unread>

--

gfre...@aol.com addressing nym-shifting senile Rodent:
"You on the other hand are a heavyweight bullshitter who demonstrates
his particular prowess at it every day."
MID: <rufg9ep6ggjdt3uek...@4ax.com>

[jim.gm4dhj]

turn down to 18C

[The Natural Philosopher]

On 30/01/2023 23:36, Bert Coules wrote:

Do you have UFH in a wooden structure floor/ceiling? Is it made of
copper or plastic pipes?

--
Socialism is the philosophy of failure, the creed of ignorance and the
gospel of envy.

Its inherent virtue is the equal sharing of misery.

Winston Churchill

[Tim Lamb]

In message <trao93$3oocj$1...@dont-email.me>, The Natural Philosopher
<t...@invalid.invalid> writes

>On 30/01/2023 23:36, Bert Coules wrote:
>> An update: with the upstairs wall thermostat turned down to 16C and
>>the UFH thus effectively switched off, the cracking noises seemed to
>>have stopped altogether, but then there was an isolated couple of
>>them (not as loud as the worst of before) quite late in the evening. 
>>I couldn't see or discover any specific triggering cause.
>> The temperature in the two rooms in the loft conversion dropped as
>>expected, stabilising around 21C thanks to the heat from downstairs.
>>This was just about tolerable for the bedroom but definitely not so
>>for the bathroom, which unfortunately wasn't given a separate zone of
>>its own.
>> This evening I returned the stat to 23C and it wasn't too long
>>before the noises returned, almost exactly as before.  I don't know
>>if I'm conveying just how loud and startling they can be: I'd record
>>them and post an audio file but without a reference level I'm not
>>convinced it would mean anything.
>> So, the experiment established that it's the heating which is
>>causing the problem; now I have to decide what to do about it.
>>
>Do you have UFH in a wooden structure floor/ceiling? Is it made of
>copper or plastic pipes?

You could try lowering the heating water temperature. 50C is good for
rapid response and probably boiler efficiency/fuel consumption but not
necessary for 24 hour occupation in a well insulated house.
>

--
Tim Lamb

[R D S]

On 28/01/2023 13:09, The Natural Philosopher wrote:
>
> I had such over the long hot summer, and I think one part of the house
> may have subsided about 3mm due to clay shrinkage. After 20 years! one
> bathroom door doesn't close right and a slight split in nearby tiles has
> appeared.

Our house plainly did some slight shifting during a long hot dry summer
then a cold winter a few years ago.
It was shortly after some building work too so I was particularly concerned.
It seems to have settled since.

[Bert Coules]

On 31/01/2023 09:50, The Natural Philosopher wrote:

> Do you have UFH in a wooden structure floor/ceiling? Is it made of > copper or plastic pipes?

Yes, the floor/ceiling is wood and the pipes are flexible plastic. I
don't know the exact details of the structure, though from a small
exposed section by the manifold it appears that the pipes are in a
screed of some sort, which presumably must in turn be supported by a
solid surface, probably chipboard. So perhaps the total "sandwich" is
(bottom to top) chipboard - screed containing pipes - chipboard - carpet.

I have wondered if the noises could be generated by the heating system
alone, not by structural movement at all.

[Bert Coules]

On 31/01/2023 10:10, Tim Lamb wrote:

> You could try lowering the heating water temperature. 50C is good for > rapid response and probably boiler efficiency/fuel consumption but
not > necessary for 24 hour occupation in a well insulated house.

Thanks for the thought. The current setting is 45C but I could try
taking down even further.

[Bert Coules]

On 31/01/2023 06:13, jim.gm4dhj wrote:

> turn down to 18C

Thanks for the thought.

[jim.gm4dhj]

the wife still listens to your stuff when cutting the lawn....quality

[The Natural Philosopher]

I suspect not if you have plastic -in - screed.
What is far more likely is that there is wood movement due to
excessively dry air under call for heat conditions.
Normal softwood will move 3-5% summer to winder across the grain and
about 1% along the grain, whereas chipboard is far more stable

>
>
>

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

[Theo]

I wonder if it's caused by boiler cycling. The boiler turns on and off
based on the heating (thermostat) demand. When the boiler is off, the water
in its flow output goes cold. The UFH manifold is mixing 'hot' boiler water
with 'cold' return water to make the 'warm' water that goes around the UFH
circuit. But with the boiler off there's no 'hot' water, so the UFH loop
goes cold. Then the boiler kicks it and starts making hot water again, so
the UFH goes warm again.

That means the water temp in the UFH cycles regularly. Every time the UFH
cycles there's expansion or contraction in the floor which makes the noises.

Is there any kind of buffer or volumiser in the system - ie a tank that
contains a volume of warm central heating water in it (which is different
from a pressure vessel)? A great volume would help to smooth out the
cycling because there's always a reservoir of 'hot' water to deal with, even
if the boiler is off, and so the UFH temp doesn't change so much.

If you can adjust the boiler and UFH mixer temps to bring them closer
together, you might find the boiler runs for longer and the UFH stays at a
more constant temperature. You could try it and see if it reduces the
regularity of the noises.

Theo

[Bert Coules]

On 31/01/2023 13:53, The Natural Philosopher wrote:

> What is far more likely is that there is wood movement due to > excessively dry air under call for heat conditions.> Normal softwood
will move 3-5% summer to winder across the grain and > about 1% along

the grain, whereas chipboard is far more stable.

Thanks for that, but would movement in a softwood structure generate the
sort of sounds I'm hearing? Groaning or creaking I could understand,
but the sharp cracks are very distinctive and sometimes extremely loud.

A piece of small-section timber snapping in two might produce something
of the sort (though not the volume) but surely if any structural members
are being that severely damaged the signs would be obvious?

I think I should find an underfloor heating specialist and get her or
his thoughts.

[Bert Coules]

On 31/01/2023 15:13, Theo wrote:

> I wonder if it's caused by boiler cycling.

Thanks for the thought; I'll investigate.

> Is there any kind of buffer or volumiser in the system?

No, nothing of that sort that I can see.

[Bert Coules]

On 31/01/2023 13:41, jim.gm4dhj wrote:

> the wife still listens to your stuff when cutting the lawn....quality

Please pass on my thanks. I hope she's moved to mow with increased energy.

[Bert Coules]

Apologies for the wayward formatting in my replies; I'm not used to
Thunderbird and suspect I've set something up incorrectly.

[The Natural Philosopher]

On 31/01/2023 16:20, Bert Coules wrote:
> On 31/01/2023 13:53, The Natural Philosopher wrote:
>
>> What is far more likely is that there is wood movement due to  >
>> excessively dry air under call for heat conditions.> Normal softwood
> will move 3-5% summer to winder across the grain and > about 1% along
> the grain, whereas chipboard is far more stable.
>
> Thanks for that, but would movement in a softwood structure generate the
> sort of sounds I'm hearing?

Yes.

>Groaning or creaking I could understand,
> but the sharp cracks are very distinctive and sometimes extremely loud.
>

They are.

> A piece of small-section timber snapping in two might produce something
> of the sort (though not the volume) but surely if any structural members
> are being that severely damaged the signs would be obvious?
>

Well what tends to happen is if tow pieces are nailed together it
creaks. If they are well screwed together, you get a sharp crack.

> I think I should find an underfloor heating specialist and get her or
> his thoughts.
>

I think you should live with it., I had such in the very hot summer,.
There seemed to have been some movement, but its over now.
>

--
You can get much farther with a kind word and a gun than you can with a
kind word alone.

Al Capone

[Bert Coules]

On 31/01/2023 18:23, The Natural Philosopher wrote:

> Well what tends to happen is if two pieces are nailed together it > creaks. If they are well screwed together, you get a sharp crack.> I
think you should live with it. I had such in the very hot summer...>
There seemed to have been some movement, but it's over now.

Thanks. It's not an easy thing to live with, even though I'm used to it
by now, but I'll consider giving it a go.

[Theo]

Bert Coules <ma...@bertcoules.co.uk> wrote:
> Thanks for that, but would movement in a softwood structure generate the
> sort of sounds I'm hearing? Groaning or creaking I could understand,
> but the sharp cracks are very distinctive and sometimes extremely loud.
>
> A piece of small-section timber snapping in two might produce something
> of the sort (though not the volume) but surely if any structural members
> are being that severely damaged the signs would be obvious?

You can get snapping noises when two items under friction slip past each
other. Friction makes movement limited, so stresses build up (the material
compresses) until suddenly the energy is released as the pieces slip
abruptly. That's the same idea as an earthquake.

For example, imagine your wooden UFH board and the substrate board
(chipboard?) are sandwiched together. Your UFH board gets warm and wants to
expand. The chipboard is cold and doesn't. The UFH wants to stretch but
can't, so it just compresses itself. Eventually the expansion gets too
much, it can't compress any further and it just has to move. The movement
is abrupt and there's a good chunk of energy released, which is why it's
a short loud noise.

I would expect UFH installers to fix the UFH with room to account for
expansion (so the floor isn't bending), but perhaps if fixed too tightly you
could get expansion noises. If it was looser the UFH board could move
freely without compressing itself, and so without noise.

Theo

[Bert Coules]

On 31/01/2023 20:44, Chris Hogg wrote:
> While I wouldn't disagree with any of what's been said before about > timbers moving, I have a radiant heater in the bathroom, one of
those> with a long silica tube with a heater coil down the inside. It
makes> extremely loud and alarming clicking noises when the metal
casing> contracts as it cools. The casing seems to act like a sounding
board> and amplify the sound. I suppose what I'm saying is not to
ignore> other possibilities, especially something metallic.
Thanks for that. I suppose the only way to really get an idea of what's
going on is to lift the carpet and at least an area of the chipboard to
expose the UFH pipes, but even that might not actually tell me anything.

[Andy Burns]

Bert Coules wrote:

> Perhaps it's because the whole ground floor of my house (with the

> exception of a small bathroom) is completely open plan, or perhaps it's

> just me, but I find that in cold weather any setting below 24C is very
> uncomfortable.  And even at 24C I frequently have to boost things with a
> separate fire.

Does it actually reach 24°C and cut the heating off, or is that what its
set for, but never really achieves it?

[Bert Coules]

On 07/02/2023 16:37, Andy Burns wrote:

> Does it actually reach 24°C and cut the heating off, or is that what its
> set for, but never really achieves it?

Sorry, I've only just seen your question. The temperature does indeed
reach 24C at which point the boiler switches off.