Re: Hot walls
Ian Stirling
> Hi,
>
> I've moved into a house and had a couple of jobs done (in this
> order)...
>
> 1) Got cavity wall insulation fitted
> 2) Replaced the electric fire with a gas fire
>
> Both jobs have been done by "professionals".
>
> The gas fire uses a pre-cast flue which is connected to a raised roof
> tile on the top of the house.
>
> Recently, when the gas fire is on at over 50%, I've noticed the wall in
> front of the metal flue is getting extremely hot. So much in fact, the
> paint is starting to blister, and the walls are too hot to touch.
>
> I'm a bit stuck at what to do next, other than not use the fire. Any
> suggestions?
I assume you've paid the 'professional' that fitted the fire?
Call them up. "I've got a flue the paint is blistering over, is this
normal, or can you come along and fix it".
"Oh, you put it in, now get here pronto before I call Trading Standards" ?
big...@meeow.co.uk
> Hi,
>
> I've moved into a house and had a couple of jobs done (in this
> order)...
>
> 1) Got cavity wall insulation fitted
> 2) Replaced the electric fire with a gas fire
>
> Both jobs have been done by "professionals".
>
> The gas fire uses a pre-cast flue which is connected to a raised roof
> tile on the top of the house.
>
> Recently, when the gas fire is on at over 50%, I've noticed the wall
in
> front of the metal flue is getting extremely hot. So much in fact,
the
> paint is starting to blister, and the walls are too hot to touch.
>
> I'm a bit stuck at what to do next, other than not use the fire. Any
> suggestions?
Where is the problem exactly? If its the paint, you should use heat
resistant paint, stripping off whats there now first.
NT
Gaz
Thanks for the replies. Yep - I paid for the work to be done. I've
called the company who installed the fire. Hopefully I'll be hearing
from them tomorrow.
The paint is flaking off on the wall between the fire surround and the
ceiling. Also noticed that in the upstairs room above the fire, the
plaster has a hairline crack in it. I guess the flue is at the other
side of the cracked plaster. The plaster is not new.
If worse comes to worse, I'll get the "company" to do a deal and
replace the gas fire with an electric one.
big...@meeow.co.uk
very odd.
BigWallop
<gary....@dsl.pipex.com> wrote in message
news:1116320493.8...@g47g2000cwa.googlegroups.com...
> Hi,
>
> I've moved into a house and had a couple of jobs done (in this
> order)...
>
> 1) Got cavity wall insulation fitted
> 2) Replaced the electric fire with a gas fire
>
> Both jobs have been done by "professionals".
>
> The gas fire uses a pre-cast flue which is connected to a raised roof
> tile on the top of the house.
>
> Recently, when the gas fire is on at over 50%, I've noticed the wall in
> front of the metal flue is getting extremely hot. So much in fact, the
> paint is starting to blister, and the walls are too hot to touch.
>
> I'm a bit stuck at what to do next, other than not use the fire. Any
> suggestions?
>
>
If the wall is getting that hot, then something needs to be done before it gets
worse. The pre-cast flue is made of what? Is it an old chimney stack?
big...@meeow.co.uk
> If the wall is getting that hot, then something needs to be done
before it gets
> worse. The pre-cast flue is made of what? Is it an old chimney
stack?
I must be in a brain warp here: as I see it, a hot stack is a _good_
thing, it means youre recovering more of the heat out of the appliance,
making its heating more effective, more powerful, reducing gas cost and
emissions.
If your paint cant take the heat, use some that can. The coal burner I
used at one place made the metal stack roasting hot, lovely, all that
heat. Luxury. It was finished in high temp paint, black to maximise IR
radiation.
Its no more of a safety isseu than having a kettle, those get hot too.
No idiot touches it twice. I'm assuming the house construction is in
line with the 1924 build regs, with struc woodwork not touching the
chimney stack. Pre 1924 properties noramlly are, as its basic common
sense.
NT
Gaz
In the loft, the flue looks like it's made out of metal. I'm not sure
if the metal goes down to the fire, or if it's something else.
The hot stack is getting too much heat. The wall above the fire
surround has paint blistering off the plaster. The room upstairs has a
gloss skirting board that's too hot to touch. It seems like a fire
waiting to happen.
I've been having a chat with a few people at work, and it seems like
the air vent at the top of the fire is too big. The vent on my fire is
about A4 in size. Most people's fires seem to have smaller vents. I
think the bigger the vent, the more heat is getting chucked up the
flue, rather than into the room.
Does that make sense?
BigWallop
"Gaz" <gary....@dsl.pipex.com> wrote in message
news:1116409510.5...@g44g2000cwa.googlegroups.com...
It all makes sense alright, but the fire was fitted professionally, wasn't it?
It could be that the flue liner, the metal stack you talk about, is far to close
to the surface for the type of gas fire you have, but it was fitted
professionally, right?
I think it's time you showed the installer what is happening, not just talking
to them on the phone. Tell them you want an engineer to come round and take a
look, or have a feel in this case, and work out exactly what the problems are.
If it is getting as hot as you're saying, then the surrounding areas of the flue
are, in my opinion, getting close to combusting. Get them back to have a feel.
John
"Gaz" <gary....@dsl.pipex.com> wrote in message
news:1116409510.5...@g44g2000cwa.googlegroups.com...
>
> In the loft, the flue looks like it's made out of metal. I'm not sure
> if the metal goes down to the fire, or if it's something else.
If it is a flueblock flue then a change to "double" skinned metal flue pipe
within the loft is normal
>
> The hot stack is getting too much heat. The wall above the fire
> surround has paint blistering off the plaster. The room upstairs has a
> gloss skirting board that's too hot to touch. It seems like a fire
> waiting to happen.
Have you posted details of what the fire actually is? Also is it suitable
for the fuel in use, i.e. if it is running on LPG is it an LPG model or is
it a Natural Gas model with larger injectors (jets) which would produce a
much bigger flame (and heat) than it should have.
>
> I've been having a chat with a few people at work, and it seems like
> the air vent at the top of the fire is too big. The vent on my fire is
> about A4 in size. Most people's fires seem to have smaller vents. I
> think the bigger the vent, the more heat is getting chucked up the
> flue, rather than into the room.
>
> Does that make sense?
It might but your description of a "vent" requires clarification. Are you
talking about an overfire flue break which will admit "lots" of cooling air
and thus could be expected to actually cool the flue products rather than
overheat the flue.
The construction of the flue may not be to standard. Has the flue been used
for a gas fire before this?
I think you should speak to the manufacturers technical department
>
big...@meeow.co.uk
> In the loft, the flue looks like it's made out of metal. I'm not sure
> if the metal goes down to the fire, or if it's something else.
so far so good. Check how close the woodwork gets up there if youve any
doubts.
> The hot stack is getting too much heat.
That makes little sense
> The wall above the fire
> surround has paint blistering off the plaster.
so use suitable paint, or use a big metal hood.
> The room upstairs has a
> gloss skirting board that's too hot to touch. It seems like a fire
> waiting to happen.
Just how hot is it? What is the temp required for spontaneous
combustion to occur? I think youll find those 2 temps are miles away.
If not, you must have quite a furnace in there. Not an industrial
monster is it?
> I've been having a chat with a few people at work, and it seems like
> the air vent at the top of the fire is too big. The vent on my fire
is
> about A4 in size. Most people's fires seem to have smaller vents. I
> think the bigger the vent, the more heat is getting chucked up the
> flue, rather than into the room.
>
> Does that make sense?
I doubt it. You havent told us which air stream goes thru the vent, so
we really dont know whats there.
I really think you dont know what whats going on yet, a good idea might
be to draw us a diagram or pic so we know what this vent is about, and
what the layout of the various bits is, including how far woodwork is
from the flue.
I presume you have a single walled metal flue, not double wall as is
common with gas appliances. But I've still heard nothing to indicate
that there is a safety problem. All I hear is its nice and hot when you
expected it to be cool...
NT
Gaz
Thanks for all the advice. A few answers (and a result?)
Yep - the fire was professionally fitted by a company.
I have been told a fire was originally installed. Although it's dubious
why the last owners replaced the fire with an eletric one.
The wall is too hot to touch.
The fire uses natural gas, with injectors I think. Not sure if any of
the previous fires used injectors.
I read the installation book that the fitter left behind last night. It
appears that I have a pre-cast flue, meaning that I've got a load of
concrete blocks with a hole in them going to the loft. Once it's at the
loft, I've got a metal pipe going to the raised roof tile. The plaster
has been applied directly to the concrete block, with no insulation.
According to the installation book, a new standard BS EN 1858 (i think)
published in 2003 says pre-cast flues must have insulation between the
concrete and plaster. It also says if it doesn't have this insulation,
no gas fire is suitable for the flue. (does this mean no gas fire with
injectors?). Looks like I'll have to opt for a balanced flue fire, or a
electric fire.
As the installer fitted the wrong type of fire for our house (although
it would be difficult to tell if the plaster is applied directly to the
concrete during the survey), I imagine I'd be able to "do a deal" on
the replacement fire.
Anyone know if it's common for pre-2000 houses to have pre-cast flues
with plaster stuck directly to them?
Gaz
This appliance has been tested for use in a pre-cast block flue
complying with BS 1289. In accordance with BS
1289 part 1, pre-cast flues built with directly plastered faces (front
or rear) are not correctly installed as to ensure
proper operation with any type of gas fire. In some instances of this
flue construction, temperature cracking of
the surface plaster may occur through no fault of the appliance. An air
gap or some form of insulation material
should be installed to prevent normal flue temperatures from damaging
wall surfaces.
BigWallop
"Gaz" <gary....@dsl.pipex.com> wrote in message
news:1116495061....@z14g2000cwz.googlegroups.com...
Then you've answered the question. The flue doesn't suit any gas fire, of any
type, model or structure. Either get the flue fixed, or go for an alternative
means of heating.
big...@meeow.co.uk
> "Gaz" <gary....@dsl.pipex.com> wrote in message
> news:1116495061....@z14g2000cwz.googlegroups.com..
> > This is what the problem is... i quote...
> >
> > This appliance has been tested for use in a pre-cast block flue
> > complying with BS 1289. In accordance with BS
> > 1289 part 1, pre-cast flues built with directly plastered faces
(front
> > or rear) are not correctly installed as to ensure
> > proper operation with any type of gas fire. In some instances of
this
> > flue construction, temperature cracking of
> > the surface plaster may occur through no fault of the appliance. An
air
> > gap or some form of insulation material
> > should be installed to prevent normal flue temperatures from
damaging
> > wall surfaces.
> Then you've answered the question. The flue doesn't suit any gas
fire, of any
> type, model or structure. Either get the flue fixed, or go for an
alternative
> means of heating.
I cant agree with your conclusion. Just because a new standard says new
installs should be done this way to prevent any chance of the plaster
cracking doesnt mean its no good. Very little in old houses meets new
build regs, and they dont need to.
The OP should stop getting his knickers in a twist and get on with
life. Your plaster has a slight chance of craking. Oh no, not the
dreaded small chance of using polyfilla!
You might be able to get some money back off the fitter if its not
fitted to the latest regs, enough to have it 'fixed' but why youd 'fix'
it I dont know. What same person chooses to have more heat go up the
chimney for no benefit? Ignorant customers can be a royal pita.
NT
John
"Gaz" <gary....@dsl.pipex.com> wrote in message
news:1116494845....@z14g2000cwz.googlegroups.com...
>
> Thanks for all the advice. A few answers (and a result?)
>
> Yep - the fire was professionally fitted by a company.
CORGI Registered I presume?
>
> I have been told a fire was originally installed. Although it's dubious
> why the last owners replaced the fire with an eletric one.
It may well be for the same reason as you will have to change yours
>
> The wall is too hot to touch.
>
> The fire uses natural gas, with injectors I think. Not sure if any of
> the previous fires used injectors.
Injector is the term for the jet or nozzle which the gas passes through. In
general all gas appliances have them
>
> I read the installation book that the fitter left behind last night. It
> appears that I have a pre-cast flue, meaning that I've got a load of
> concrete blocks with a hole in them going to the loft. Once it's at the
> loft, I've got a metal pipe going to the raised roof tile. The plaster
> has been applied directly to the concrete block, with no insulation.
Therein lies your problem. You now have a decision to make. either change
from a flued gas fire to one with a balanced or power flue or have the
chimney breast replastered using plasterboard with dot and dab to provide an
air break between the hot blockwork and the finish.
>
> According to the installation book, a new standard BS EN 1858 (i think)
> published in 2003 says pre-cast flues must have insulation between the
> concrete and plaster. It also says if it doesn't have this insulation,
> no gas fire is suitable for the flue. (does this mean no gas fire with
> injectors?). Looks like I'll have to opt for a balanced flue fire, or a
> electric fire.
This is probably the simplest and most cost effective solution.
>
> As the installer fitted the wrong type of fire for our house (although
> it would be difficult to tell if the plaster is applied directly to the
> concrete during the survey), I imagine I'd be able to "do a deal" on
> the replacement fire.
Good luck
>
> Anyone know if it's common for pre-2000 houses to have pre-cast flues
> with plaster stuck directly to them?
>
Unfortunately its all too common.
ell...@gmail.com
ell...@gmail.com
If an old granny paid £1400 for getting a fire fitted, you can't
expect her to be whipping the polyfilla out every month to repair
cracks. Not to mention the having to constantly paint to the filler.
big...@meeow.co.uk
> Are you a retard or cowboy?
no
> If an old granny paid £1400 for getting a fire fitted, you can't
> expect her to be whipping the polyfilla out every month to repair
> cracks.
That is not at all a realistic description of the situation.
> Not to mention the having to constantly paint to the filler.
nor is that. Lots of houses have uninsulated flues and are fine. Its
silly to get knickers in a twist over it.
NT
ell...@gmail.com
misses, and getting told to "stop getting his knickers in a twist and
get on with life " didn't help.
Now that I know lots of other houses have similar problems, maybe I
should just live with it.
The Natural Philosopher
big...@meeow.co.uk
Sorry for being rude as well.
The natural philospoher:
>However, they are contra to modern bulding regs for gas fires.
Yes, as are the majority of houses in this country. It is not a
problem, beyond one of paperwork.
The build regs at the start of the 20th century made real changes to
housebuilding, helping to ensure better standards were met, in most
cases. But as with many such things, they took on a life and momentum
of their own, and no-one has really stopped to question the illogical
maths behind many of todays regs.
Today we are at the point where at one end of the scale some BRs are
about safety and utilty, and at the other end, some are about trying to
avoid that one in a million case of problems down the line, and
achieving that it at a cost of 1000x times the cost of letting that one
problem occur and paying to fix it if it does. This is one of the
reasons our house prices are so high - only one of them.
Look at our Victorian housing. Most of it is fine, no significant
problems, yet they fail to meet todays BRs in more or less every single
area. It simply isnt a significant problem.
A single insulated flue may not conform to paperwork requirements, but
in terms of functionality it is actually better. More energy efficient,
lower run cost, heats the house faster and more evenly, less polluting.
If you decide to live with it, you may need to remove and use more
suitable paint. (There are other options.) But to remove the gas fire
and fit electric to me makes no sense at all. Electric is 3x as costly
to run, will cost money to supply and fit, and you'll gain absolutely
nothing as a result.
Similarly, replacing the flue will gain you all of nothing.
NT
alison sanderson
hi further to this post jI have just had a new gas fire and pre cast flue
fitted and the walls are hot above the fire, what sort of insulation does it
have to have special kind and what plaster is the best to have as my normal
plaster is already cracking ? o any advice welcome thanks
--
for full context, visit http://www.homeownershub.com/uk-diy/hot-walls-179821-.htm
newshound
> replying to The Natural Philosopher, alison sanderson wrote:
> hi further to this post jI have just had a new gas fire and pre cast flue
> fitted and the walls are hot above the fire, what sort of insulation
> does it
> have to have special kind and what plaster is the best to have as my
> normal
> plaster is already cracking ? o any advice welcome thanks
a temperature measurement?
Andrew
> replying to The Natural Philosopher, alison sanderson wrote:
> hi further to this post jI have just had a new gas fire and pre cast flue
> fitted and the walls are hot above the fire, what sort of insulation
> does it
> have to have special kind and what plaster is the best to have as my
> normal
> plaster is already cracking ? o any advice welcome thanks
Do yourself a favour and install a proper newsgroup reader
on your PC and select UK.d-i-y as one of your preferred
groups.
Class 2 flue blocks are never fitted to new properties now
since 2004 when condensing boilers became mandatory. I
doubt if they have been used for new builds since about 1980,
and many were installed by utterly incompetent builders anyway
(*) and have long since been condemned by BG.
(*) Poorly made mortar joints, mortar 'snots' chucked down
inside cavity and even down inside the flue blocks.
Sam Plusnet
<eImdnXaGZdutVL3F...@brightview.co.uk>,
news...@stevejqr.plus.com says...
silly website.
alison sanderson
i cant but its so hot you have to draw your hand away initially , to the left
and right is cold just the middle that gets hot, i have called the engineer
that installed it back and will check it has been insulated , is there any
special insulation or plaster i should use or will normal plaster be ok if its
insulated? thank you for your help and advice
John Rumm
configured to inject its URL into every post - its not something it lets
you turn off.
--
Cheers,
John.
/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
John Rumm
> hi further to this post jI have just had a new gas fire and pre cast flue
> fitted and the walls are hot above the fire, what sort of insulation
> does it
> have to have special kind and what plaster is the best to have as my
> normal
> plaster is already cracking ? o any advice welcome thanks
driven off. In some respects a hot flue is good for driving more heat
into the house.
harry
John Rumm
> On Monday, 7 November 2016 22:10:20 UTC, John Rumm wrote:
>> On 07/11/2016 17:44, alison sanderson wrote:
>>> replying to The Natural Philosopher, alison sanderson wrote:
>>> hi further to this post jI have just had a new gas fire and pre cast flue
>>> fitted and the walls are hot above the fire, what sort of insulation
>>> does it
>>> have to have special kind and what plaster is the best to have as my
>>> normal
>>> plaster is already cracking ? o any advice welcome thanks
>>
>> It will probably crack a bit and then stop once any residual moisture is
>> driven off. In some respects a hot flue is good for driving more heat
>> into the house.
(I know you are not good at comprehending what you read, but aside from
being appended to an old thread, this was a new question. Vis: "further
fitted"
Dave W
"John Rumm" <see.my.s...@nowhere.null> wrote in message
news:-JudnfNYGveHPLzF...@brightview.co.uk...
the link to it.
--
Dave W
Tim+
>
> Strangely, poor Alison's posting does not appear on homeownershub, despite
> the link to it.
is that all threads are sorted by date of *first* post, not date of most
recent message.
Consequently, when posters append their question to an ancient thread
(that's been promoted by HOH), they can only find replies by searching back
through the ancient threads.
Tim
--
Please don't feed the trolls
John Rumm
> "John Rumm" <see.my.s...@nowhere.null> wrote in message
> news:-JudnfNYGveHPLzF...@brightview.co.uk...
>> On 08/11/2016 07:47, harry wrote:
>>> On Monday, 7 November 2016 22:10:20 UTC, John Rumm wrote:
>>>> On 07/11/2016 17:44, alison sanderson wrote:
>>>>> replying to The Natural Philosopher, alison sanderson wrote:
>>>>> hi further to this post jI have just had a new gas fire and pre cast
>>>>> flue
>>>>> fitted and the walls are hot above the fire, what sort of insulation
>>>>> does it
>>>>> have to have special kind and what plaster is the best to have as my
>>>>> normal
>>>>> plaster is already cracking ? o any advice welcome thanks
>>>>
>>>> It will probably crack a bit and then stop once any residual moisture is
>>>> driven off. In some respects a hot flue is good for driving more heat
>>>> into the house.
>>
>>
>>> Replying to more ten year old posts then!
>>
>> No harry, I was replying to yesterdays post. Do try to keep up.
>>
>> (I know you are not good at comprehending what you read, but aside from
>> being appended to an old thread, this was a new question. Vis: "further to
>> this post jI have just had a new gas fire and pre cast flue
>> fitted"
> the link to it.
Dave W
"John Rumm" <see.my.s...@nowhere.null> wrote in message
at the bottom. I see these usenet messages are all being copied to the
website. Someone needs to devise a DoS attack on it!
--
Dave W
John Rumm
> Thanks John. I didn't spot the page index at the top as most websites put it
> at the bottom. I see these usenet messages are all being copied to the
> website. Someone needs to devise a DoS attack on it!
the case right now.
Andrew
> replying to newshound, alison sanderson wrote:
> i cant but its so hot you have to draw your hand away initially , to
> the left
> and right is cold just the middle that gets hot, i have called the engineer
> that installed it back and will check it has been insulated , is there any
> special insulation or plaster i should use or will normal plaster be ok
> if its
> insulated? thank you for your help and advice
flue gases could be up to 250 centigrade above the
flame and that heat has to go somewhere.
The heating effect of the hot flue block (being part
of the inner leaf of the cavity wall), allows a
smaller radiator to be specified in the upstairs
room that the flue passes through.
downstairs, the flue blocks are generally hidden
behind a false chimney breast.
Minor cracking of the plaster is inevitable unless
the walls have been dry-lined over the flue blocks
with a small air gap between plasterboard and wall.
Few builders will have bothered to do this though.
alan_m
>> It's another spamming attempt to drive traffic to that
>> silly website.
>
> I doubt the users are party to the game - its just the way its
> configured to inject its URL into every post - its not something it lets
> you turn off.
>
>
>
to is 11 years old.
--
mailto: news {at} admac {dot] myzen {dot} co {dot} uk
John Rumm
> On 07/11/2016 22:08, John Rumm wrote:
>
>>> It's another spamming attempt to drive traffic to that
>>> silly website.
>>
>> I doubt the users are party to the game - its just the way its
>> configured to inject its URL into every post - its not something it lets
>> you turn off.
>>
>>
>>
> Its not just the advertising URL - it's also that the post being replied
> to is 11 years old.