Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

The flat was originally heated by warm air ducts from a central off peak
store so there is also an opportunity for a centrally located
extractor/dehumidifier.

Does anyone have insight to the benefits/drawbacks etc?

regards
--
Tim Lamb

In article ,
Tim Lamb writes:
Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

The flat was originally heated by warm air ducts from a central off peak
store so there is also an opportunity for a centrally located
extractor/dehumidifier.

Does anyone have insight to the benefits/drawbacks etc?

Nowhere near enough info to diagnose the problem, which is necessary
before any remedy can be suggested.

What sort of heating is there now?
Does the place feel warm, or is the heating ineffective?
What moisture sources are there? Cooking, baths/showers, clothes drying, ...?
When does the condensation/damp appear?
Where does the condensation/damp appear?
Any idea what thermal insulation is installed?
Are there any extractors, ventilators, etc.
Has it always been like this? If not, what happened to cause the change?

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

In message , Andrew Gabriel
writes
In article ,
Tim Lamb writes:
Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

The flat was originally heated by warm air ducts from a central off peak
store so there is also an opportunity for a centrally located
extractor/dehumidifier.

Does anyone have insight to the benefits/drawbacks etc?

Nowhere near enough info to diagnose the problem, which is necessary
before any remedy can be suggested.

:-)

First engage your advisor!

What sort of heating is there now?

Conventional full gas CH

Does the place feel warm, or is the heating ineffective?

Depends on how the tenants set the rad. stats but the system is amply
sized.

What moisture sources are there? Cooking, baths/showers, clothes drying, ...?

Cooking, baths/showers. Hopefully not clothes drying as there is a
condensing washer/drier.

When does the condensation/damp appear?

Particularly after a let this Winter.

Where does the condensation/damp appear?

On upper surfaces of North and shaded exterior walls. Manly bathroom and
bedroom.

Any idea what thermal insulation is installed?

11" cavity wall only. A tentative enquiry to BG bounced as insulation
could only be grant aided if *all* the flats in the block were done.

Are there any extractors, ventilators, etc.

No extractors. Double glazing has trickle vents. Kitchen has double air
brick but buried behind cupboards. Cooker hood is re-circ type.

Has it always been like this? If not, what happened to cause the change?

We thought the CH had solved the problem which had been noticeable with
the old air duct/ storage system. However a long, cold Winter coupled
with a family and children.....

More ventilation and more heat input but you can't stand guard over
tenants.
We were arranging a simple bathroom extractor (timed on exit if
possible) and realised the added expense of part P. One step further to
a heat recovery, low voltage extractor. But are there any *gotchers*?

Because large parts of the old ducting system are still there, a
centralised system might be possible but issues such as noise, cost of
running a dehumidifier, disposal of condensate, pressure balancing etc.
are a bit mind numbing.

I think we should pursue the cavity insulation aspect despite British
Gas. I believe the building is based on a concrete frame so the cavities
might be stopped at each floor.

regards




--
Tim Lamb

On Mar 29, 10:03*pm, Tim Lamb wrote:
In message , Andrew Gabriel
writes



In article ,
* * * Tim Lamb writes:
Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

The flat was originally heated by warm air ducts from a central off peak
store so there is also an opportunity for a centrally located
extractor/dehumidifier.

Does anyone have insight to the benefits/drawbacks etc?

Nowhere near enough info to diagnose the problem, which is necessary
before any remedy can be suggested.

:-)

First engage your advisor!



What sort of heating is there now?

Conventional full gas CH

Does the place feel warm, or is the heating ineffective?

Depends on how the tenants set the rad. stats but the system is amply
sized.

What moisture sources are there? Cooking, baths/showers, clothes drying, ...?

Cooking, baths/showers. Hopefully not clothes drying as there is a
condensing washer/drier.

When does the condensation/damp appear?

Particularly after a let this Winter.

Where does the condensation/damp appear?

On upper surfaces of North and shaded exterior walls. Manly bathroom and
bedroom.

Any idea what thermal insulation is installed?

11" cavity wall only. A tentative enquiry to BG bounced as insulation
could only be grant aided if *all* the flats in the block were done.

Are there any extractors, ventilators, etc.

No extractors. Double glazing has trickle vents. Kitchen has double air
brick but buried behind cupboards. Cooker hood is re-circ type.

Has it always been like this? If not, what happened to cause the change?

We thought the CH had solved the problem which had been noticeable with
the old air duct/ storage system. However a long, cold Winter coupled
with a family and children.....

More ventilation and more heat input but you can't stand guard over
tenants.
* We were arranging a simple bathroom extractor (timed on exit if
possible) and realised the added expense of part P. One step further to
a heat recovery, low voltage extractor. But are there any *gotchers*?

Because large parts of the old ducting system are still there, a
centralised system might be possible but issues such as noise, cost of
running a dehumidifier, disposal of condensate, pressure balancing etc.
are a bit mind numbing.

I'm not clear if that means you own the block rather than the one
flat? If the latter, a plugin dehumidifier is a surer approach than
ventilation, and costs less to run and is trivial to install.
Condensate is plumbed to a waste pipe


I think we should pursue the cavity insulation aspect despite British
Gas. I believe the building is based on a concrete frame so the cavities
might be stopped at each floor.

CWI makes a lot of sense. Grants arent necessary to make it pay. Brush
strips can be used to retain insulation for shared walls. Adhesive on
the insulation can prevent it going anywhere after installation.

CWI won't reduce the water load in the air though, either you prevent/
remove it somehow or condensation is inevitable. The usual simple
guidelines like using lids on pans are too often impossible to
implement with tenants, but you can dehumidify. A contract clause can
state that if disabling climate control equipment causes mould, rot
etc they're liable for the damage.


NT

On Mon, 29 Mar 2010 11:30:26 +0100, Tim Lamb wrote:

Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

I recently fitted a Kair unit in a bathroom for folks who were having
humidity and mould problems despite the existing humidistat fan. They say
it's fixed the problem, though it seems a short time to tell.

Bit fiddly to fit, not least requiring a 150mm core drill. And don't
forget to buy the special screwdriver bit!

Note the humidity sensor is in the control box with the mains transformer
so your mains kit is still in the bathroom.



--
John Stumbles -- http://yaph.co.uk

Time flies like an arrow
Fruit flies like a banana
Tits like coconuts

In message
, NT
writes
On Mar 29, 10:03*pm, Tim Lamb wrote:
In message , Andrew Gabriel
writes



In article ,
* * * Tim Lamb writes:
Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

The flat was originally heated by warm air ducts from a central off peak
store so there is also an opportunity for a centrally located
extractor/dehumidifier.

Does anyone have insight to the benefits/drawbacks etc?

Nowhere near enough info to diagnose the problem, which is necessary
before any remedy can be suggested.

:-)

First engage your advisor!



What sort of heating is there now?

Conventional full gas CH

Does the place feel warm, or is the heating ineffective?

Depends on how the tenants set the rad. stats but the system is amply
sized.

What moisture sources are there? Cooking, baths/showers, clothes
drying, ...?

Cooking, baths/showers. Hopefully not clothes drying as there is a
condensing washer/drier.

When does the condensation/damp appear?

Particularly after a let this Winter.

Where does the condensation/damp appear?

On upper surfaces of North and shaded exterior walls. Manly bathroom and
bedroom.

Any idea what thermal insulation is installed?

11" cavity wall only. A tentative enquiry to BG bounced as insulation
could only be grant aided if *all* the flats in the block were done.

Are there any extractors, ventilators, etc.

No extractors. Double glazing has trickle vents. Kitchen has double air
brick but buried behind cupboards. Cooker hood is re-circ type.

Has it always been like this? If not, what happened to cause the change?

We thought the CH had solved the problem which had been noticeable with
the old air duct/ storage system. However a long, cold Winter coupled
with a family and children.....

More ventilation and more heat input but you can't stand guard over
tenants.
* We were arranging a simple bathroom extractor (timed on exit if
possible) and realised the added expense of part P. One step further to
a heat recovery, low voltage extractor. But are there any *gotchers*?

Because large parts of the old ducting system are still there, a
centralised system might be possible but issues such as noise, cost of
running a dehumidifier, disposal of condensate, pressure balancing etc.
are a bit mind numbing.

I'm not clear if that means you own the block rather than the one
flat? If the latter, a plugin dehumidifier is a surer approach than
ventilation, and costs less to run and is trivial to install.

One ground floor flat in a 3 storey block, 60's build. Unfortunately
rather a lot of exterior walls.

Condensate is plumbed to a waste pipe

Yes. The flat has two bedrooms, bathroom, toilet, lounge and kitchen all
arranged around a central access corridor. I doubt the practicality of
fitting a cheap dehumidifier in the bathroom although air could be
extracted through existing ducts to something fitted off the corridor.
All the waste pipes are on exterior walls.


I think we should pursue the cavity insulation aspect despite British
Gas. I believe the building is based on a concrete frame so the cavities
might be stopped at each floor.

CWI makes a lot of sense. Grants arent necessary to make it pay. Brush
strips can be used to retain insulation for shared walls. Adhesive on
the insulation can prevent it going anywhere after installation.

Brush strips?

Also, if the cavity is open, the junction is horizontal rather than
vertical.

CWI won't reduce the water load in the air though, either you prevent/
remove it somehow or condensation is inevitable. The usual simple
guidelines like using lids on pans are too often impossible to
implement with tenants, but you can dehumidify. A contract clause can
state that if disabling climate control equipment causes mould, rot
etc they're liable for the damage.

So far it has been superficial mould requiring laborious cleaning.

Up to 85% recovery is claimed for extractor units or is this overly
optimistic? I think the bathroom is the obvious start point. Material
cost around 200ukp so payback within one months rent.

regards

--
Tim Lamb

In message , YAPH
writes
On Mon, 29 Mar 2010 11:30:26 +0100, Tim Lamb wrote:

Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

I recently fitted a Kair unit in a bathroom for folks who were having
humidity and mould problems despite the existing humidistat fan. They say
it's fixed the problem, though it seems a short time to tell.

OK sounds promising.

Bit fiddly to fit, not least requiring a 150mm core drill. And don't
forget to buy the special screwdriver bit!

Hmm.. the clutch on my SDS drill doesn't like core drills:-(

Note the humidity sensor is in the control box with the mains transformer
so your mains kit is still in the bathroom.

Ah! Pity. The electrician was muttering about bonding incoming water
pipes, two pole isolation etc.

I think there are at least two other manufacturers but the Kair looked
the most sensible.

regards




--
Tim Lamb

On Tue, 30 Mar 2010 10:29:46 +0100, Tim Lamb wrote:

Hmm.. the clutch on my SDS drill doesn't like core drills:-(

It certainly won't like a 150mm one then!
A few years ago I bit the bullet and bought a 'proper' core drill - though
the 'Sparky' brand which was under £150 (IIRC) at screwfix rather than
better-known brands at 2 or 3 times the price. Shouldn't tempt fate by
saying so but It's still going strong after many dozens of holes of all
sizes over the years.


--
John Stumbles -- http://yaph.co.uk

Question Authority

On Mar 30, 10:22*am, Tim Lamb wrote:
In message
, NT
writes
On Mar 29, 10:03*pm, Tim Lamb wrote:
In message , Andrew Gabriel
writes
In article ,
* * * Tim Lamb writes:


Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

The flat was originally heated by warm air ducts from a central off peak
store so there is also an opportunity for a centrally located
extractor/dehumidifier.

Does anyone have insight to the benefits/drawbacks etc?

Nowhere near enough info to diagnose the problem, which is necessary
before any remedy can be suggested.

:-)

First engage your advisor!

What sort of heating is there now?

Conventional full gas CH

Does the place feel warm, or is the heating ineffective?

Depends on how the tenants set the rad. stats but the system is amply
sized.

What moisture sources are there? Cooking, baths/showers, clothes
drying, ...?

Cooking, baths/showers. Hopefully not clothes drying as there is a
condensing washer/drier.

When does the condensation/damp appear?

Particularly after a let this Winter.

Where does the condensation/damp appear?

On upper surfaces of North and shaded exterior walls. Manly bathroom and
bedroom.

Any idea what thermal insulation is installed?

11" cavity wall only. A tentative enquiry to BG bounced as insulation
could only be grant aided if *all* the flats in the block were done.

Are there any extractors, ventilators, etc.

No extractors. Double glazing has trickle vents. Kitchen has double air
brick but buried behind cupboards. Cooker hood is re-circ type.

Has it always been like this? If not, what happened to cause the change?

We thought the CH had solved the problem which had been noticeable with
the old air duct/ storage system. However a long, cold Winter coupled
with a family and children.....

More ventilation and more heat input but you can't stand guard over
tenants.
* We were arranging a simple bathroom extractor (timed on exit if
possible) and realised the added expense of part P. One step further to
a heat recovery, low voltage extractor. But are there any *gotchers*?

Because large parts of the old ducting system are still there, a
centralised system might be possible but issues such as noise, cost of
running a dehumidifier, disposal of condensate, pressure balancing etc..
are a bit mind numbing.

I'm not clear if that means you own the block rather than the one
flat? If the latter, *a plugin dehumidifier is a surer approach than
ventilation, and costs less to run and is trivial to install.

One ground floor flat in a 3 storey block, 60's build. Unfortunately
rather a lot of exterior walls.

Condensate is plumbed to a waste pipe

Yes. The flat has two bedrooms, bathroom, toilet, lounge and kitchen all
arranged around a central access corridor. I doubt the practicality of
fitting a cheap dehumidifier in the bathroom although air could be
extracted through existing ducts to something fitted off the corridor.
All the waste pipes are on exterior walls.

Using flexible 1/4" tube for a dehumidifier makes it relatively easy
to plumb.


I think we should pursue the cavity insulation aspect despite British
Gas. I believe the building is based on a concrete frame so the cavities
might be stopped at each floor.

CWI makes a lot of sense. Grants arent necessary to make it pay. Brush
strips can be used to retain insulation for shared walls. Adhesive on
the insulation can prevent it going anywhere after installation.

Brush strips?

yup, theyre poked into position to stop the insulation passing.

Also, if the cavity is open, the junction is horizontal rather than
vertical.



CWI won't reduce the water load in the air though, either you prevent/
remove it somehow or condensation is inevitable. The usual simple
guidelines like using lids on pans are too often impossible to
implement with tenants, but you can dehumidify. A contract clause can
state that if disabling climate control equipment causes mould, rot
etc they're liable for the damage.

So far it has been superficial mould requiring laborious cleaning.

thats good news, if you put a dehumidifier in the right place it
should clear it up.


Up to 85% recovery is claimed for extractor units or is this overly
optimistic? I think the bathroom is the obvious start point. Material
cost around 200ukp so payback within one months rent.

'upto.' Dehumidifiers give 100% heat recovery all the time. And no
installation cost.

regards


NT

In message
, NT
writes

Yes. The flat has two bedrooms, bathroom, toilet, lounge and kitchen all
arranged around a central access corridor. I doubt the practicality of
fitting a cheap dehumidifier in the bathroom although air could be
extracted through existing ducts to something fitted off the corridor.
All the waste pipes are on exterior walls.

Using flexible 1/4" tube for a dehumidifier makes it relatively easy
to plumb.

Hmm... Solid floors and across the corridor. Might be able to pick up
the washing m/c waste from behind the kitchen units. My only experience
of de-humidifiers is the floor standing, wheel about variety. Is
something available which would not object to an intake fed from a 4"
duct? Discharge could be into the airing cupboard.


I think we should pursue the cavity insulation aspect despite British
Gas. I believe the building is based on a concrete frame so the cavities
might be stopped at each floor.

CWI makes a lot of sense. Grants arent necessary to make it pay. Brush
strips can be used to retain insulation for shared walls. Adhesive on
the insulation can prevent it going anywhere after installation.

Brush strips?

yup, theyre poked into position to stop the insulation passing.

These would need to be horizontal, mostly. I intend to follow up on the
actual structure as the cavities may already be closed at each floor.

Also, if the cavity is open, the junction is horizontal rather than
vertical.



CWI won't reduce the water load in the air though, either you prevent/
remove it somehow or condensation is inevitable. The usual simple
guidelines like using lids on pans are too often impossible to
implement with tenants, but you can dehumidify. A contract clause can
state that if disabling climate control equipment causes mould, rot
etc they're liable for the damage.

So far it has been superficial mould requiring laborious cleaning.

thats good news, if you put a dehumidifier in the right place it
should clear it up.


Up to 85% recovery is claimed for extractor units or is this overly
optimistic? I think the bathroom is the obvious start point. Material
cost around 200ukp so payback within one months rent.

'upto.' Dehumidifiers give 100% heat recovery all the time. And no
installation cost.

Still got to couple up ducting and bore through internal walls but,
yes:-)

regards

--
Tim Lamb

In message , YAPH
writes
On Tue, 30 Mar 2010 10:29:46 +0100, Tim Lamb wrote:

Hmm.. the clutch on my SDS drill doesn't like core drills:-(

It certainly won't like a 150mm one then!
A few years ago I bit the bullet and bought a 'proper' core drill - though
the 'Sparky' brand which was under £150 (IIRC) at screwfix rather than
better-known brands at 2 or 3 times the price. Shouldn't tempt fate by
saying so but It's still going strong after many dozens of holes of all
sizes over the years.

Mine is a Kango 340. I have been meaning to ask the group if repairs are
possible.

regards



--
Tim Lamb

In message
,
Owain writes
On 29 Mar, 22:03, Tim Lamb wrote:
No extractors. Double glazing has trickle vents. Kitchen has double air
brick but buried behind cupboards. Cooker hood is re-circ type.

Change cooker hood to an extract type (if it's an electric cooker,
wire it into the cooker switch so the cooker can't be used without the
fan.)

Yes. More holes through cavity walls! Might be do-able if there is space
over the wall cupboards for the ducting.

* We were arranging a simple bathroom extractor (timed on exit if
possible) and realised the added expense of part P. One step further to
a heat recovery, low voltage extractor. But are there any *gotchers*?

You might be able to use an in-line duct fan, so taking the electric
bit outside the bathroom.

Yes. That was the electricians suggestion. Suspended for further noise
reduction. Lots of duct but possible. There is a convenient space over
the corridor. Are there rules governing positioning of exhaust ducts
close to gas boiler flues?

regards

--
Tim Lamb

"Tim Lamb" wrote in message
news
In message , Andrew Gabriel
writes
In article ,
Tim Lamb writes:
Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

The flat was originally heated by warm air ducts from a central off peak
store so there is also an opportunity for a centrally located
extractor/dehumidifier.

Does anyone have insight to the benefits/drawbacks etc?

Nowhere near enough info to diagnose the problem, which is necessary
before any remedy can be suggested.

:-)

First engage your advisor!

What sort of heating is there now?

Conventional full gas CH

Does the place feel warm, or is the heating ineffective?

Depends on how the tenants set the rad. stats but the system is amply
sized.

What moisture sources are there? Cooking, baths/showers, clothes drying,
...?

Cooking, baths/showers. Hopefully not clothes drying as there is a
condensing washer/drier.

When does the condensation/damp appear?

Particularly after a let this Winter.

Where does the condensation/damp appear?

On upper surfaces of North and shaded exterior walls. Manly bathroom and
bedroom.

Any idea what thermal insulation is installed?

11" cavity wall only. A tentative enquiry to BG bounced as insulation
could only be grant aided if *all* the flats in the block were done.

Are there any extractors, ventilators, etc.

No extractors. Double glazing has trickle vents. Kitchen has double air
brick but buried behind cupboards. Cooker hood is re-circ type.

Has it always been like this? If not, what happened to cause the change?

We thought the CH had solved the problem which had been noticeable with
the old air duct/ storage system. However a long, cold Winter coupled with
a family and children.....

More ventilation and more heat input but you can't stand guard over
tenants.
We were arranging a simple bathroom extractor (timed on exit if possible)
and realised the added expense of part P. One step further to a heat
recovery, low voltage extractor. But are there any *gotchers*?

Because large parts of the old ducting system are still there, a
centralised system might be possible but issues such as noise, cost of
running a dehumidifier, disposal of condensate, pressure balancing etc.
are a bit mind numbing.

I think we should pursue the cavity insulation aspect despite British Gas.
I believe the building is based on a concrete frame so the cavities might
be stopped at each floor.

My parents own the middle floor of a 3 flats. They managed to get cavity
wall insulation done recently. It just needs the people above and below to
have theirs done at the same time. Not everyone paid the same price as my
parents did not qualify for a full discount as it is not their place of
residence. I believe that they paid £150.

A humidistat fan in the bathroom may be better than a timed fan. And what
silly prices have you been quoted for a fan installing?

Cheers

Adam

In message , ARWadsworth
writes

We were arranging a simple bathroom extractor (timed on exit if possible)
and realised the added expense of part P. One step further to a heat
recovery, low voltage extractor. But are there any *gotchers*?

Because large parts of the old ducting system are still there, a
centralised system might be possible but issues such as noise, cost of
running a dehumidifier, disposal of condensate, pressure balancing etc.
are a bit mind numbing.

I think we should pursue the cavity insulation aspect despite British Gas.
I believe the building is based on a concrete frame so the cavities might
be stopped at each floor.

My parents own the middle floor of a 3 flats. They managed to get cavity
wall insulation done recently. It just needs the people above and below to
have theirs done at the same time. Not everyone paid the same price as my
parents did not qualify for a full discount as it is not their place of
residence. I believe that they paid £150.

A humidistat fan in the bathroom may be better than a timed fan. And what
silly prices have you been quoted for a fan installing?

Huh! Still waiting.

Although the gas main (plastic up to the meter box) has been bonded,
incoming water supply and bathroom piping/metalwork have not.

We discussed fitting an in line ducted extractor with the estimator but,
as has been pointed out, any humidistat would have to be in the bathroom
itself and back to part P.

Whatever is done has to be tenant proof.

regards
--
Tim Lamb

"Tim Lamb" wrote in message
...
In message , ARWadsworth
writes

We were arranging a simple bathroom extractor (timed on exit if
possible)
and realised the added expense of part P. One step further to a heat
recovery, low voltage extractor. But are there any *gotchers*?

Because large parts of the old ducting system are still there, a
centralised system might be possible but issues such as noise, cost of
running a dehumidifier, disposal of condensate, pressure balancing etc.
are a bit mind numbing.

I think we should pursue the cavity insulation aspect despite British
Gas.
I believe the building is based on a concrete frame so the cavities
might
be stopped at each floor.

My parents own the middle floor of a 3 flats. They managed to get cavity
wall insulation done recently. It just needs the people above and below to
have theirs done at the same time. Not everyone paid the same price as my
parents did not qualify for a full discount as it is not their place of
residence. I believe that they paid £150.

A humidistat fan in the bathroom may be better than a timed fan. And what
silly prices have you been quoted for a fan installing?

Huh! Still waiting.

Although the gas main (plastic up to the meter box) has been bonded,
incoming water supply and bathroom piping/metalwork have not.

We discussed fitting an in line ducted extractor with the estimator but,
as has been pointed out, any humidistat would have to be in the bathroom
itself and back to part P.

Unless it is a very small bathroom or the layout is awkard you can have a
humidistat in the bathroom. I realise part P would apply, this in many cases
is very little extra cost. Your additional costs are obviously the incoming
mains bonding and the supplementary bonding (either lots of wires and clamps
or use an RCD for the bathroom electrics). Once the electrics are up to
current standards the only extra cost of part P is the cost of registering
the work when you do a job.



Whatever is done has to be tenant proof.

Indeed. But is that possible?

Cheers

Adam