improving floor insulation

[Geoff Pearson]

I am thinking of improving the floor insulation of my house. Under the
ground floor of my 1897 stone-built house in Edinburgh I have a space about
1.6m high under all the rooms so access for work is very good. My energy
bills (gas+electricity) are about £2800 a year.

The floor is a standard Edinburgh floor: 11 inch joists with the space
between filled with ash and covered in plaster, supported on riven wooden
strips, themselves supported on battens along the joists. This deafening
(as it is called here) is about 3-4" thick. The floor is standard 1 1/8
inch tongued and grooved boards. The space below the riven timber strips to
the lower edge of the joists is about 6".

So there is space to add insulation below the deafening and access is easy.

First question: is it worth doing? With deafening in place that provides
quite a thick layer - but then in more modern houses cavity walls do get
insulated so maybe the deafening is not a good thermal insulator (although
good for sound). Insulation is cheap enough and it is bound to reduce my
costs - more importantly it might make the place warmer.

Second question: how to do it? I can put mineral wool rolls in the space
and hold it in place with netting. Or should it be slabs of something? Do
I need vapour barrier - I think not?

[fred]

Post by Geoff Pearson
Second question: how to do it? I can put mineral wool rolls in the space
and hold it in place with netting. Or should it be slabs of something? Do
I need vapour barrier - I think not?

This has been done to death on uk.d-i-y over the years and the advice
given is still valid, can I suggest you have a search on google groups
group:uk.d-i-y and come back with questions on anything not covered
there.

With bills that high I assume draughts are a more likely source of your
heat loss. Floor insulation can generally be assigned a lower priority
but you usually end up fixing floor draughts at the same time. For info,
a draughty 5mm gap between floor and skirting on a good sized Scottish
lounge room is equivalent to having a window open 100mm. How draughty
are your windows? Also, tenement or proper house, it makes a difference.

[Geoff Pearson]

Post by fred

Post by Geoff Pearson
Second question: how to do it? I can put mineral wool rolls in the space
and hold it in place with netting. Or should it be slabs of something?
Do
I need vapour barrier - I think not?

This has been done to death on uk.d-i-y over the years and the advice
given is still valid, can I suggest you have a search on google groups
group:uk.d-i-y and come back with questions on anything not covered there.
With bills that high I assume draughts are a more likely source of your
heat loss. Floor insulation can generally be assigned a lower priority but
you usually end up fixing floor draughts at the same time. For info, a
draughty 5mm gap between floor and skirting on a good sized Scottish
lounge room is equivalent to having a window open 100mm. How draughty are
your windows? Also, tenement or proper house, it makes a difference.
--
fred
it's a ba-na-na . . . .

Actually, insulating an "Edinburgh" floor does not seem to be covered much
elsewhere. English suspended floors seem to be joists and planks and nowt
else so there is a lot on them. There are drawings like my house on on
http://www.changeworks.org.uk/uploads/83096-EnergyHeritage_online1.pdf (page
39 et seq).


It is a mid terrace house, two storey, with virtually air-tight windows
(brush strips etc), doors likewise, so the remaining obvious air entry
points are though the floor (sanded bare boards with rugs). Skirtings have
mouse-mouldings so they are sealed. Many of my neighbours have full
basements which are semi-habitable rooms. The ground rises slightly under
mine so the room shapes are there but not the height.

[fred]

Post by Geoff Pearson

Post by fred

Post by Geoff Pearson
Second question: how to do it? I can put mineral wool rolls in the space
and hold it in place with netting. Or should it be slabs of something?
Do
I need vapour barrier - I think not?

This has been done to death on uk.d-i-y over the years and the advice
given is still valid, can I suggest you have a search on google groups
group:uk.d-i-y and come back with questions on anything not covered there.
With bills that high I assume draughts are a more likely source of your
heat loss. Floor insulation can generally be assigned a lower priority but
you usually end up fixing floor draughts at the same time. For info, a
draughty 5mm gap between floor and skirting on a good sized Scottish
lounge room is equivalent to having a window open 100mm. How draughty are
your windows? Also, tenement or proper house, it makes a difference.
--
fred
it's a ba-na-na . . . .

Actually, insulating an "Edinburgh" floor does not seem to be covered much
elsewhere. English suspended floors seem to be joists and planks and nowt
else so there is a lot on them. There are drawings like my house on on
http://www.changeworks.org.uk/uploads/83096-EnergyHeritage_online1.pdf (page
39 et seq).

Fair comment. If you have been braving the heritage sites for
information[1] then you have my sympathy and are well deserving of help.

Here's my take:

The floor build isn't that different from that in the intermediate
floors of Glasgow tenements but of course they do not require insulation
due to thermal balance with properties above and below.

It's difficult to say why they put this in at the ground floor level
except that it would provide a fire break if the basement was in use and
that it would provide a basic level of insulation.

As you already have some insulation (the deadening) then adding more
will put you at risk of interstitial condensation leading to rot. I
think this is more of a risk when insulating loft spaces in heritage
buildings and current advice there is to insulate with fibreglass or
rockwool w/o a vapour barrier but to inspect the ceiling joists in the
roof space at regular intervals to ensure that there is not a
condensation problem. The problem is less pronounced in floors so I
would still omit the vapour barrier as there is little guarantee that it
can be done effectively and there is a risk of trapped (and hidden)
moisture in the event of interstitial condensation or in the case of a
large spill or flood from above.

The suggestion to avoid a vapour barrier unfortunately precludes the use
of foil backed PIR insulation (Celotex et al) as the foil backing forms
a vapour barrier.

That leaves fibreglass or rockwool applied in depth (8-10"
suggested[2]). That is what I have used here ( Glasgow tenement floor)
but don't expect it to be an easy fit as the concept of, "simply hold in
place with netting" is a fallacy. The glass doesn't want to stay up
where it is put and you get an inevitable sag when the netting becomes
loaded. You can however make a temporary fix with string strung tightly
between pre-placed clout nails in a diagonal, zig-zag arrangement. This
then gives you time to staple in netting tightly. To get a tight fill
I'd recommend an inch or so compression on the glass when the net is
initially installed. Also to avoid an unintentional moisture trap I
would avoid bagged fibreglass products such as spaceblanket.

By far the most important issue IMO is to avoid drafts circumventing
your new insulation. This means sealing the edges of the deadening layer
to make sure that not draughts can penetrate.

Post by Geoff Pearson
It is a mid terrace house, two storey, with virtually air-tight windows
(brush strips etc), doors likewise, so the remaining obvious air entry
points are though the floor (sanded bare boards with rugs). Skirtings have
mouse-mouldings so they are sealed. Many of my neighbours have full
basements which are semi-habitable rooms. The ground rises slightly under
mine so the room shapes are there but not the height.

Well done on the windows and I assume the loft is already done? Despite
my best efforts at draught proofing, I felt that bare boards were asking
for it so I went for fitted carpets laid over tape sealed hardboard.

An IR thermometer is invaluable in spotting heat loss, just look cold
surfaces. Also, there's nothing better for detecting draughts than
crawling about on the floor with your sensitive facial skin near
potential sources, they should show up easily on a windy day.

There is one final alternative and that is to rip down the deadening and
replace it with close fitted and foam sealed Celotex but that would be a
lot of work and very messy although it would pretty much guarantee the
absence of draughts coming through gaps in the floor.

Good luck and hope that helps.

[1] IME, on insulation, they tell you to be very careful, give you all
the options but stop short of actually making any real recommendations.
[2] Cross batten and add another layer if you don't have that much joist
depth.

[Geoff Pearson]

Post by fred

Post by Geoff Pearson

Post by fred

Post by Geoff Pearson
Second question: how to do it? I can put mineral wool rolls in the space
and hold it in place with netting. Or should it be slabs of something?
Do
I need vapour barrier - I think not?

This has been done to death on uk.d-i-y over the years and the advice
given is still valid, can I suggest you have a search on google groups
group:uk.d-i-y and come back with questions on anything not covered there.
With bills that high I assume draughts are a more likely source of your
heat loss. Floor insulation can generally be assigned a lower priority but
you usually end up fixing floor draughts at the same time. For info, a
draughty 5mm gap between floor and skirting on a good sized Scottish
lounge room is equivalent to having a window open 100mm. How draughty are
your windows? Also, tenement or proper house, it makes a difference.
--
fred
it's a ba-na-na . . . .

Actually, insulating an "Edinburgh" floor does not seem to be covered much
elsewhere. English suspended floors seem to be joists and planks and nowt
else so there is a lot on them. There are drawings like my house on on
http://www.changeworks.org.uk/uploads/83096-EnergyHeritage_online1.pdf (page
39 et seq).

Fair comment. If you have been braving the heritage sites for
information[1] then you have my sympathy and are well deserving of help.
The floor build isn't that different from that in the intermediate floors
of Glasgow tenements but of course they do not require insulation due to
thermal balance with properties above and below.
It's difficult to say why they put this in at the ground floor level
except that it would provide a fire break if the basement was in use and
that it would provide a basic level of insulation.
As you already have some insulation (the deadening) then adding more will
put you at risk of interstitial condensation leading to rot. I think this
is more of a risk when insulating loft spaces in heritage buildings and
current advice there is to insulate with fibreglass or rockwool w/o a
vapour barrier but to inspect the ceiling joists in the roof space at
regular intervals to ensure that there is not a condensation problem. The
problem is less pronounced in floors so I would still omit the vapour
barrier as there is little guarantee that it can be done effectively and
there is a risk of trapped (and hidden) moisture in the event of
interstitial condensation or in the case of a large spill or flood from
above.
The suggestion to avoid a vapour barrier unfortunately precludes the use
of foil backed PIR insulation (Celotex et al) as the foil backing forms a
vapour barrier.
That leaves fibreglass or rockwool applied in depth (8-10" suggested[2]).
That is what I have used here ( Glasgow tenement floor) but don't expect
it to be an easy fit as the concept of, "simply hold in place with
netting" is a fallacy. The glass doesn't want to stay up where it is put
and you get an inevitable sag when the netting becomes loaded. You can
however make a temporary fix with string strung tightly between pre-placed
clout nails in a diagonal, zig-zag arrangement. This then gives you time
to staple in netting tightly. To get a tight fill I'd recommend an inch or
so compression on the glass when the net is initially installed. Also to
avoid an unintentional moisture trap I would avoid bagged fibreglass
products such as spaceblanket.
By far the most important issue IMO is to avoid drafts circumventing your
new insulation. This means sealing the edges of the deadening layer to
make sure that not draughts can penetrate.

Post by Geoff Pearson
It is a mid terrace house, two storey, with virtually air-tight windows
(brush strips etc), doors likewise, so the remaining obvious air entry
points are though the floor (sanded bare boards with rugs). Skirtings have
mouse-mouldings so they are sealed. Many of my neighbours have full
basements which are semi-habitable rooms. The ground rises slightly under
mine so the room shapes are there but not the height.

Well done on the windows and I assume the loft is already done? Despite my
best efforts at draught proofing, I felt that bare boards were asking for
it so I went for fitted carpets laid over tape sealed hardboard.
An IR thermometer is invaluable in spotting heat loss, just look cold
surfaces. Also, there's nothing better for detecting draughts than
crawling about on the floor with your sensitive facial skin near potential
sources, they should show up easily on a windy day.
There is one final alternative and that is to rip down the deadening and
replace it with close fitted and foam sealed Celotex but that would be a
lot of work and very messy although it would pretty much guarantee the
absence of draughts coming through gaps in the floor.
Good luck and hope that helps.
[1] IME, on insulation, they tell you to be very careful, give you all the
options but stop short of actually making any real recommendations.
[2] Cross batten and add another layer if you don't have that much joist
depth.
--
fred
it's a ba-na-na . . . .

fred

thank you so much for this comprehensive reply. Excellent advice.

I now also see that the Energy Savings Trust may do this for free (only in
some areas including Edinburgh - so I will ask them to do a survey - that is
free too.

Geoff

[fred]

Post by Geoff Pearson
thank you so much for this comprehensive reply. Excellent advice.

You're welcome and I hope it goes well.

The only thing I forgot to mention was to go very carefully if there is
any hint of dampness in the underfloor or if any efflorescence is
present but I'm guessing you would have mentioned that if there was any.

Post by Geoff Pearson
I now also see that the Energy Savings Trust may do this for free (only in
some areas including Edinburgh - so I will ask them to do a survey - that is
free too.

Great, well worth a try if you can get it but they may insist on a
complete package including ugly plastic self adhesive brush carriers on
internal and external doors, not nice. I have seen a recent grant aided
job done by British Gas subbies in a Glasgow tenement loft and it was
very well done. As usual, jobsworth survey/management looking to penny
pinch but the guys on the job were keen to do a good job when they met a
knowledgeable householder, top lads.

[Geoff Pearson]

Post by fred

Post by Geoff Pearson
thank you so much for this comprehensive reply. Excellent advice.

You're welcome and I hope it goes well.
The only thing I forgot to mention was to go very carefully if there is
any hint of dampness in the underfloor or if any efflorescence is present
but I'm guessing you would have mentioned that if there was any.

Post by Geoff Pearson
I now also see that the Energy Savings Trust may do this for free (only in
some areas including Edinburgh - so I will ask them to do a survey - that is
free too.

Great, well worth a try if you can get it but they may insist on a
complete package including ugly plastic self adhesive brush carriers on
internal and external doors, not nice. I have seen a recent grant aided
job done by British Gas subbies in a Glasgow tenement loft and it was very
well done. As usual, jobsworth survey/management looking to penny pinch
but the guys on the job were keen to do a good job when they met a
knowledgeable householder, top lads.
--
fred
it's a ba-na-na . . . .

What there is in the under floor area is a non-stop blow through the house.
Really well ventilated - which is good but I want to keep that out of the
inhabited zone.

[The Real Doctor]

Post by fred
As you already have some insulation (the deadening)

<pedant>

No, it really is called deafening, as he wrote. Perhaps it's an
Edinburgh thing.

</pedant>

Ian

[Julian Bradfield]

Post by The Real Doctor

Post by fred
As you already have some insulation (the deadening)

<pedant>
No, it really is called deafening, as he wrote. Perhaps it's an
Edinburgh thing.
</pedant>

Don't think so. The OED says:

ˈdeafening n. material used for this purpose, pugging:
deafening-board, a board fixed between floor-joints to prevent sound
from passing through the floor.
1839 M. Lafever Mod. Archit. 111 Strips nailed on the sides of the
beams, to support the deafening board.
1864 Glasgow Herald 9 Apr., The heavy load of earth which has been
put in for deafening.

so at least in 1864 it was also a Glasgow thing!

I confess the word "pugging" was new to me.

[The Real Doctor]

Post by Julian Bradfield
I confess the word "pugging" was new to me.

I think it's like dogging, but with a pug.

Ian

[Grimly Curmudgeon]

On Sun, 9 Dec 2012 15:33:41 -0000, "Geoff Pearson"

Post by Geoff Pearson
There are drawings like my house on on
http://www.changeworks.org.uk/uploads/83096-EnergyHeritage_online1.pdf (page
39 et seq).

There are no graphics on that doc, just text and boxes. Is it opening
ok on yours? I'm using Foxit, which is fine with everything else.

[Geoff Pearson]

Post by Grimly Curmudgeon
On Sun, 9 Dec 2012 15:33:41 -0000, "Geoff Pearson"

Post by Geoff Pearson
There are drawings like my house on on
http://www.changeworks.org.uk/uploads/83096-EnergyHeritage_online1.pdf (page
39 et seq).

There are no graphics on that doc, just text and boxes. Is it opening
ok on yours? I'm using Foxit, which is fine with everything else.

Yes - even on IE9! It is a pdf which I open in Acrobat Reader and they
printed.

[Andy Burns]

Post by Grimly Curmudgeon

Post by Geoff Pearson
http://www.changeworks.org.uk/uploads/83096-EnergyHeritage_online1.pdf

There are no graphics on that doc, just text and boxes. Is it opening
ok on yours? I'm using Foxit

Fine here with SumatraPDF and Evince ...

[Geoff Pearson]

Post by Geoff Pearson
I am thinking of improving the floor insulation of my house. Under the
ground floor of my 1897 stone-built house in Edinburgh I have a space
about 1.6m high under all the rooms so access for work is very good. My
energy bills (gas+electricity) are about £2800 a year.
The floor is a standard Edinburgh floor: 11 inch joists with the space
between filled with ash and covered in plaster, supported on riven wooden
strips, themselves supported on battens along the joists. This deafening
(as it is called here) is about 3-4" thick. The floor is standard 1 1/8
inch tongued and grooved boards. The space below the riven timber strips
to the lower edge of the joists is about 6".
So there is space to add insulation below the deafening and access is easy.
First question: is it worth doing? With deafening in place that provides
quite a thick layer - but then in more modern houses cavity walls do get
insulated so maybe the deafening is not a good thermal insulator (although
good for sound). Insulation is cheap enough and it is bound to reduce my
costs - more importantly it might make the place warmer.
Second question: how to do it? I can put mineral wool rolls in the space
and hold it in place with netting. Or should it be slabs of something?
Do I need vapour barrier - I think not?

Just to finish the story: The Energy Savings Trust arranged for Carillion to
do the work, paid for by Edinburgh Council/Scottish Government, for no cost
to me in April. All complete in two hours - now I have to work out if it
makes a difference.

[Andrew Mawson]

Post by Geoff Pearson

Post by Geoff Pearson
I am thinking of improving the floor insulation of my house. Under the
ground floor of my 1897 stone-built house in Edinburgh I have a space
about 1.6m high under all the rooms so access for work is very good. My
energy bills (gas+electricity) are about £2800 a year.
The floor is a standard Edinburgh floor: 11 inch joists with the space
between filled with ash and covered in plaster, supported on riven wooden
strips, themselves supported on battens along the joists. This deafening
(as it is called here) is about 3-4" thick. The floor is standard 1 1/8
inch tongued and grooved boards. The space below the riven timber strips
to the lower edge of the joists is about 6".
So there is space to add insulation below the deafening and access is easy.
First question: is it worth doing? With deafening in place that provides
quite a thick layer - but then in more modern houses cavity walls do get
insulated so maybe the deafening is not a good thermal insulator
(although good for sound). Insulation is cheap enough and it is bound to
reduce my costs - more importantly it might make the place warmer.
Second question: how to do it? I can put mineral wool rolls in the space
and hold it in place with netting. Or should it be slabs of something?
Do I need vapour barrier - I think not?

Just to finish the story: The Energy Savings Trust arranged for Carillion
to do the work, paid for by Edinburgh Council/Scottish Government, for no
cost to me in April. All complete in two hours - now I have to work out if
it makes a difference.

When we did our house re-furb we insulated the suspended ground floor by
loosely stretching nylon mesh (*) across the joists, and placing cavity wall
insulation batts between the joists supported by the mesh. Mesh was stapled
to stop it moving, then we laid the flooring on top. Worked very well and
kept a ventilated space below.

(* the sort used for fruit cages)

AWEM

[Geoff Pearson]

Post by Andrew Mawson

Post by Geoff Pearson

Post by Geoff Pearson
I am thinking of improving the floor insulation of my house. Under the
ground floor of my 1897 stone-built house in Edinburgh I have a space
about 1.6m high under all the rooms so access for work is very good. My
energy bills (gas+electricity) are about £2800 a year.
The floor is a standard Edinburgh floor: 11 inch joists with the space
between filled with ash and covered in plaster, supported on riven
wooden strips, themselves supported on battens along the joists. This
deafening (as it is called here) is about 3-4" thick. The floor is
standard 1 1/8 inch tongued and grooved boards. The space below the
riven timber strips to the lower edge of the joists is about 6".
So there is space to add insulation below the deafening and access is easy.
First question: is it worth doing? With deafening in place that
provides quite a thick layer - but then in more modern houses cavity
walls do get insulated so maybe the deafening is not a good thermal
insulator (although good for sound). Insulation is cheap enough and it
is bound to reduce my costs - more importantly it might make the place
warmer.
Second question: how to do it? I can put mineral wool rolls in the
space and hold it in place with netting. Or should it be slabs of
something? Do I need vapour barrier - I think not?

Just to finish the story: The Energy Savings Trust arranged for Carillion
to do the work, paid for by Edinburgh Council/Scottish Government, for no
cost to me in April. All complete in two hours - now I have to work out
if it makes a difference.

When we did our house re-furb we insulated the suspended ground floor by
loosely stretching nylon mesh (*) across the joists, and placing cavity
wall insulation batts between the joists supported by the mesh. Mesh was
stapled to stop it moving, then we laid the flooring on top. Worked very
well and kept a ventilated space below.
(* the sort used for fruit cages)
AWEM

That is pretty much what I have as a result of this free work: 150mm of
fibreglass suspended between the joists. I had a void of 1.5 metres below
the ground floor so it was easy.

[stuart noble]

Post by Andrew Mawson

Post by Geoff Pearson

Post by Geoff Pearson
I am thinking of improving the floor insulation of my house. Under
the ground floor of my 1897 stone-built house in Edinburgh I have a
space about 1.6m high under all the rooms so access for work is very
good. My energy bills (gas+electricity) are about £2800 a year.
The floor is a standard Edinburgh floor: 11 inch joists with the
space between filled with ash and covered in plaster, supported on
riven wooden strips, themselves supported on battens along the
joists. This deafening (as it is called here) is about 3-4" thick.
The floor is standard 1 1/8 inch tongued and grooved boards. The
space below the riven timber strips to the lower edge of the joists
is about 6".
So there is space to add insulation below the deafening and access is easy.
First question: is it worth doing? With deafening in place that
provides quite a thick layer - but then in more modern houses cavity
walls do get insulated so maybe the deafening is not a good thermal
insulator (although good for sound). Insulation is cheap enough and
it is bound to reduce my costs - more importantly it might make the
place warmer.
Second question: how to do it? I can put mineral wool rolls in the
space and hold it in place with netting. Or should it be slabs of
something? Do I need vapour barrier - I think not?

Just to finish the story: The Energy Savings Trust arranged for
Carillion to do the work, paid for by Edinburgh Council/Scottish
Government, for no cost to me in April. All complete in two hours -
now I have to work out if it makes a difference.

When we did our house re-furb we insulated the suspended ground floor by
loosely stretching nylon mesh (*) across the joists, and placing cavity
wall insulation batts between the joists supported by the mesh. Mesh was
stapled to stop it moving, then we laid the flooring on top. Worked very
well and kept a ventilated space below.
(* the sort used for fruit cages)
AWEM

Could you have supported the batts with nails? I think I'd find that
easier, but I've never actually tried it

[Windmill]

Post by Geoff Pearson
Just to finish the story: The Energy Savings Trust arranged for Carillion to
do the work, paid for by Edinburgh Council/Scottish Government, for no cost
to me in April. All complete in two hours - now I have to work out if it
makes a difference.

What exactly did they do about things like wiring strung across joists?

I've asked about insulation in the past but was told that no grants
were available, though the house in question sounds similar to yours:
two story terraced (but split into an upper and lower flat), with a 1.5m
crawl space underneath the ground floor ventilated to the outside, flat
cold as all hell in winter.

I think it could be made tolerable in its uninsulated condition with
10KW of storage heating, but that would cost ~200 per month.

Luckily I grew up at a time when there was no heat in any house until a
fire had been lit, remember times when water in a flower vase beside
the window froze overnight, and although I've become a bit soft as the
years go by am willing to add extra clothing by day and use an electric
blanket by night . (Better still, though, is not to be there at all!)

[Geoff Pearson]

Post by Windmill

Post by Geoff Pearson
Just to finish the story: The Energy Savings Trust arranged for Carillion to
do the work, paid for by Edinburgh Council/Scottish Government, for no cost
to me in April. All complete in two hours - now I have to work out if it
makes a difference.

What exactly did they do about things like wiring strung across joists?
I've asked about insulation in the past but was told that no grants
two story terraced (but split into an upper and lower flat), with a 1.5m
crawl space underneath the ground floor ventilated to the outside, flat
cold as all hell in winter.
I think it could be made tolerable in its uninsulated condition with
10KW of storage heating, but that would cost ~200 per month.
Luckily I grew up at a time when there was no heat in any house until a
fire had been lit, remember times when water in a flower vase beside
the window froze overnight, and although I've become a bit soft as the
years go by am willing to add extra clothing by day and use an electric
blanket by night . (Better still, though, is not to be there at all!)
--
All that is gold does not glister / Not all who wander are lost

I wired the house 25 years ago - I didn't have much in the way of
cross-joist wiring - I mainly took it to the wall and traversed from there.
I didn't have a grant - they just did it - no conditions, no personal
details, no means test (the house is worth towards £500k).

[Windmill]

"Geoff Pearson" <***@hotmail.com> writes:

[...............]

Post by Geoff Pearson
I wired the house 25 years ago - I didn't have much in the way of
cross-joist wiring - I mainly took it to the wall and traversed from there.
I didn't have a grant - they just did it - no conditions, no personal
details, no means test (the house is worth towards £500k).

In mine, half the size so maybe worth half that, there's a lot of
cross-joist wiring (not done by me I will add) which I imagine could be
a problem when adding insulation between the joists.

I'll be interested to hear of your experiences next winter.

[Geoff Pearson]

Post by Windmill
[...............]

Post by Geoff Pearson
I wired the house 25 years ago - I didn't have much in the way of
cross-joist wiring - I mainly took it to the wall and traversed from there.
I didn't have a grant - they just did it - no conditions, no personal
details, no means test (the house is worth towards £500k).

In mine, half the size so maybe worth half that, there's a lot of
cross-joist wiring (not done by me I will add) which I imagine could be
a problem when adding insulation between the joists.
I'll be interested to hear of your experiences next winter.
--
All that is gold does not glister / Not all who wander are lost

Where there is cross-joist stuff they seem to have torn the fibreglass and
reconnected by overlapping it behind the pipe or wire - which is fine.