Attic Roof Insulation
 

Can anyone help? We are wanting to insulate between the rafters of our
attic roof which are about 90mm in depth. It is an old house (1900),
the roof is tiled and doesn't have roof felt or sacking so the
insulation would back on to the roof tiles. We have read you need a
space of 50mm between the insulation and the roof tiles and some
suggestions that instead of insulating between the rafters you should
insulate across them. My thoughts are to get some 50mm Kingspan
insulation and leave a 40mm to the tiles given the age of the house
and the fact that there is unlikely to be condensation problems given
the age of the house and there being no roof felt barrier. Is 50mm
enough? Are there any guidelines?
Any advice welcomed - thanks in advance.

Attic Roof Insulation
 

Having looked at Kingspan TP10 literature it seems to suggest that it
is rafter level insulation with no condensation risk - does this mean
no need for a gap and the ability to put in a thicker depth of
insulation or is 50mm enough? Is TP10 the best stuff for between
rafters insulation? Thanks.

Attic Roof Insulation
 

Attic Roof Insulation
 

Attic Roof Insulation
 

Attic Roof Insulation
 

The Natural Philosopher wrote:

Polyisocyanurate is the best commercial material for insulation there
is. Kingspan and celotex ate the current dogs ********.

Must remember that next time we get a puppy - cheaper than paying the vet.

David

Attic Roof Insulation
 

In article , The Natural
Philosopher writes
wrote:
Having looked at Kingspan TP10 literature it seems to suggest that it
is rafter level insulation with no condensation risk - does this mean
no need for a gap and the ability to put in a thicker depth of
insulation or is 50mm enough? Is TP10 the best stuff for between
rafters insulation? Thanks.

I think what the condensation bit means is that it is foil covered, and
impermeable. It doesn't mean that you don't need a gap.

You need to ventilate those rafters for sure. The air above will be wet
in humid weather, and at night you may well get condensation running
down the top surface as the temp goes below dew point. That has to be
allowed to run away down to the eaves and the residue evaporate.

Polyisocyanurate is the best commercial material for insulation there
is. Kingspan and celotex ate the current dogs ********.


Thinking more about this, if you have the space, Id be tempted to try
and mount the stoff OFF the rafters altogether - to make a 'tent' of
insulation underneath, because I am concerned that condensation above
the insulation layer may in time affect the rafters: when you take a
roof that expects heat to bleed from below to help keep it dry, and then
seal that heat off..things change. And you have no sarking..so its
slightly unusual.

Although it does take up more space I agree with your last suggestion,
if the rafters do get wet for any reason and there is material between
them you will have damp timber in an enclosed trench which will have no
opportunity to dry out, potentially leading to rot problems.
--
fred
Plusnet - I hope you like vanilla

Attic Roof Insulation
 

In article ,
writes:
Can anyone help? We are wanting to insulate between the rafters of our
attic roof which are about 90mm in depth. It is an old house (1900),

Why are you wanting to do this?
If you just want to insulate the storage space, then 25mm sheet
screwed to the rafters would be fine, and you will get nearly
all the same benefits as a thicker layer as the benefits don't
scale anything like with the thickness.
OTOH, if you are looking to insulate as part of a loft conversion,
then you'll need to conform to building regs requirments.
Also, what if any loft insulation if there already?

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

Attic Roof Insulation
 

In article ,
The Natural Philosopher writes:

Thinking more about this, if you have the space, Id be tempted to try
and mount the stoff OFF the rafters altogether - to make a 'tent' of
insulation underneath, because I am concerned that condensation above
the insulation layer may in time affect the rafters: when you take a

I did this with a lean-to construction roof (over my bathroom).
I fixed the underside of the rafters with pressure treated roofing
battens at right angles, and then fixed the Kingspan to those (or in
most cases through those into the rafters. I provided a vent in the gable
end above the Kingspan, and the roofing felt looped down enough to
provide further ventilation. The rafters showed some signs of rot which
had been repaired (before my time, probably when slates were replaced),
and I wanted to make sure they stayed very well ventilated.
My worry was not condensation, but any water ingress through the roof
which I would likely not notice one the Kingspan was in place, and
without ventilation might lead to serious rotting of the rafters.

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

Attic Roof Insulation
 

On 8 Jan, 14:44, (Andrew Gabriel) wrote:
In article ,
* * * * The Natural Philosopher writes:



Thinking more about this, if you have the space, Id be tempted to try
and mount the stoff OFF the rafters altogether - to make a 'tent' of
insulation underneath, because I am concerned that condensation above
the insulation layer may in time affect the rafters: when you take a

I did this with a lean-to construction roof (over my bathroom).
I fixed the underside of the rafters with pressure treated roofing
battens at right angles, and then fixed the Kingspan to those (or in
most cases through those into the rafters. I provided a vent in the gable
end above the Kingspan, and the roofing felt looped down enough to
provide further ventilation. The rafters showed some signs of rot which
had been repaired (before my time, probably when slates were replaced),
and I wanted to make sure they stayed very well ventilated.
My worry was not condensation, but any water ingress through the roof
which I would likely not notice one the Kingspan was in place, and
without ventilation might lead to serious rotting of the rafters.

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

Dear all, thanks for your replies. I am the posters other half. The
loft is actually an attic room that had a low ceiling with no
insulation behind it and a couple of plaster board dividers behind
which the tiles have always been exposed (not weight bearing walls or
anyhting just boards) we want to use the room as a bedroom and
insulate it properly, as it was too cold in winter and too hot in
summer. It has an original window in the side gable. So we have taken
the ceiling down (100 years of muck) so now we have a roof that needs
some insulation before we can plaster and redecorate so it is not
quite a conversion just a bit of updating. With that in mind. would
you give the same advice?,
thanks for your help!

Attic Roof Insulation
 

wrote in message
...
Can anyone help? We are wanting to insulate between the rafters of our
attic roof which are about 90mm in depth. It is an old house (1900),
the roof is tiled and doesn't have roof felt or sacking so the
insulation would back on to the roof tiles. We have read you need a
space of 50mm between the insulation and the roof tiles and some
suggestions that instead of insulating between the rafters you should
insulate across them. My thoughts are to get some 50mm Kingspan
insulation and leave a 40mm to the tiles given the age of the house
and the fact that there is unlikely to be condensation problems given
the age of the house and there being no roof felt barrier. Is 50mm
enough? Are there any guidelines?
Any advice welcomed - thanks in advance.

Have you investigated Renotherm? http://www.renotherm.co.uk/
I'd be interested to hear if anyone has used this company or similar.
Michael (with a similar problem) .

Attic Roof Insulation
 

Attic Roof Insulation
 

On Tue, 8 Jan 2008 19:54:23 -0000, Michael Shergold wrote:

Have you investigated Renotherm? http://www.renotherm.co.uk/
I'd be interested to hear if anyone has used this company or similar.

I wouldn't touch it with a barge pole. How does any damp that gets onto
the timbers get out again in a timely manner? To me it's asking for the
roof timbers to rot. And when the time comes to replace the roof properly
it's going to be a right mess and probably require far more replacement
timber than otherwise would be required. As a buyer of a property I'd be
very wary of place with it, what is it hiding?

In the long term and for sale-abilty you are far better off stripping the
roof, replacing timbers as required, putting on a modern breathable
sarking and replacing the orginal tiles/slates. You will need some new but
put them round the back or something.

--
Cheers
Dave. pam is missing e-mail

Attic Roof Insulation
 

The Natural Philosopher wrote:
wrote:
On 8 Jan, 14:44, (Andrew Gabriel) wrote:
In article ,
� � � � The Natural Philosopher writes:



Thinking more about this, if you have the space, Id be tempted to try
and mount the stoff OFF the rafters altogether - to make a 'tent' of
insulation underneath, because I am concerned that condensation above
the insulation layer may in time affect the rafters: when you take a
I did this with a lean-to construction roof (over my bathroom).
I fixed the underside of the rafters with pressure treated roofing
battens at right angles, and then fixed the Kingspan to those (or in
most cases through those into the rafters. I provided a vent in the
gable
end above the Kingspan, and the roofing felt looped down enough to
provide further ventilation. The rafters showed some signs of rot which
had been repaired (before my time, probably when slates were replaced),
and I wanted to make sure they stayed very well ventilated.
My worry was not condensation, but any water ingress through the roof
which I would likely not notice one the Kingspan was in place, and
without ventilation might lead to serious rotting of the rafters.

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

Dear all, thanks for your replies. I am the posters other half. The
loft is actually an attic room that had a low ceiling with no
insulation behind it and a couple of plaster board dividers behind
which the tiles have always been exposed (not weight bearing walls or
anyhting just boards) we want to use the room as a bedroom and
insulate it properly, as it was too cold in winter and too hot in
summer. It has an original window in the side gable. So we have taken
the ceiling down (100 years of muck) so now we have a roof that needs
some insulation before we can plaster and redecorate so it is not
quite a conversion just a bit of updating. With that in mind. would
you give the same advice?,
thanks for your help!


Basically yes. All becomes clear. If you have the space, insulate under,
if not insulate between and in all cases make airtight and tape it all
up. Leave at least some gap above.

Be careful at the eaves..You MAY get water dripping off the top edge of
the celotex here. put some kind of plastic sheet to let it come out at
the eaves, not down into the walls.

My instinct would be to tape plastic to the underside of the insulation
and let it hang over the edges of the rafter bearer plates, before re
boarding the thing.







50mm rockwool slabs between the rafters makes a huge difference, and
Celotex even more so. Either would leave you with the recommended gap,
but the rockwool packs you can sling in the back of a car rather than
having to arrange delivery, and they're a fair bit cheaper.
I found the key to a tight fit was to slightly overcut the width, then
wedge one end in and run a hand saw flat against the side of the joist,
cutting the insulation at the same time. That way any variation in width
is accommodated.

Attic Roof Insulation
 

"Dave Liquorice" wrote in message
ll.net...
On Tue, 8 Jan 2008 19:54:23 -0000, Michael Shergold wrote:

Have you investigated Renotherm? http://www.renotherm.co.uk/
I'd be interested to hear if anyone has used this company or similar.

I wouldn't touch it with a barge pole. How does any damp that gets onto
the timbers get out again in a timely manner? To me it's asking for the
roof timbers to rot. And when the time comes to replace the roof properly
it's going to be a right mess and probably require far more replacement
timber than otherwise would be required. As a buyer of a property I'd be
very wary of place with it, what is it hiding?

In the long term and for sale-abilty you are far better off stripping the
roof, replacing timbers as required, putting on a modern breathable
sarking and replacing the orginal tiles/slates. You will need some new but
put them round the back or something.

--
Cheers
Dave. pam is missing e-mail



The best advice yet, Dave

Attic Roof Insulation
 

Dave Liquorice wrote:
On Tue, 8 Jan 2008 19:54:23 -0000, Michael Shergold wrote:

Have you investigated Renotherm? http://www.renotherm.co.uk/
I'd be interested to hear if anyone has used this company or similar.

I wouldn't touch it with a barge pole.

If you put that into your loft I wouldn't buy your house.

Andy

Attic Roof Insulation
 

In article ,
Andy Champ says...
Dave Liquorice wrote:
On Tue, 8 Jan 2008 19:54:23 -0000, Michael Shergold wrote:

Have you investigated Renotherm? http://www.renotherm.co.uk/
I'd be interested to hear if anyone has used this company or similar.

I wouldn't touch it with a barge pole.

If you put that into your loft I wouldn't buy your house.

Andy


Interesting that roof insulation experts always talk about
leaving an air gap between slates and insulation. That
product is sprayed directly onto the tiles. Is that the
problem with it?
--
David in Normandy

Attic Roof Insulation
 

On Wed, 09 Jan 2008 20:21:34 +0000, Andy Champ wrote:

Dave Liquorice wrote:
On Tue, 8 Jan 2008 19:54:23 -0000, Michael Shergold wrote:

Have you investigated Renotherm? http://www.renotherm.co.uk/ I'd be
interested to hear if anyone has used this company or similar.

I wouldn't touch it with a barge pole.

If you put that into your loft I wouldn't buy your house.


OK, I'll bite. This stuff has been around now long enough to show any bad
effects - have any been seen in the flesh?

My (rented) place has the attic done like this. Seems OK so far, but then
again I don't know how long it's been in place...


I presume the issue is condensation/rot in the timbers?

Attic Roof Insulation
 

PCPaul wrote:
On Wed, 09 Jan 2008 20:21:34 +0000, Andy Champ wrote:

Dave Liquorice wrote:
On Tue, 8 Jan 2008 19:54:23 -0000, Michael Shergold wrote:

Have you investigated Renotherm? http://www.renotherm.co.uk/ I'd be
interested to hear if anyone has used this company or similar.
I wouldn't touch it with a barge pole.
If you put that into your loft I wouldn't buy your house.


OK, I'll bite. This stuff has been around now long enough to show any bad
effects - have any been seen in the flesh?

My (rented) place has the attic done like this. Seems OK so far, but then
again I don't know how long it's been in place...


I presume the issue is condensation/rot in the timbers?

I might be paranoid, and wrong, but I don't need to take the chance.

When this is on the inside of the tiles the condition of the timbers
cannot be assessed. It's been used because there is some kind of problem
with the roof, and it hides whatever the problem is. That's enough to
put me off.

Andy

Attic Roof Insulation
 

David in Normandy wrote:
In article ,
Andy Champ says...
Dave Liquorice wrote:
On Tue, 8 Jan 2008 19:54:23 -0000, Michael Shergold wrote:

Have you investigated Renotherm? http://www.renotherm.co.uk/
I'd be interested to hear if anyone has used this company or similar.
I wouldn't touch it with a barge pole.
If you put that into your loft I wouldn't buy your house.

Andy


Interesting that roof insulation experts always talk about
leaving an air gap between slates and insulation. That
product is sprayed directly onto the tiles. Is that the
problem with it?
Largely, yes.

Attic Roof Insulation
 

PCPaul wrote:
On Wed, 09 Jan 2008 20:21:34 +0000, Andy Champ wrote:

Dave Liquorice wrote:
On Tue, 8 Jan 2008 19:54:23 -0000, Michael Shergold wrote:

Have you investigated Renotherm? http://www.renotherm.co.uk/ I'd be
interested to hear if anyone has used this company or similar.
I wouldn't touch it with a barge pole.
If you put that into your loft I wouldn't buy your house.


OK, I'll bite. This stuff has been around now long enough to show any bad
effects - have any been seen in the flesh?

My (rented) place has the attic done like this. Seems OK so far, but then
again I don't know how long it's been in place...


I presume the issue is condensation/rot in the timbers?


Yup.

Any water that gets under the slates into the beams will dry very slowly.

The whole key to damp control, is either to keep it ALL out, or let air
circulate to dry out any that gets in.

this product does neither. Nor will ity be easy to replace any damaged
roof slates etc.


Essentially 30 years on, the whole roof will start to sag and slip, and
will need total replacement, like as not.

Thats may not be an issue today, but 20 years down the line, some
surveyor is going to knock off 30 grand (or whatever a new roof costs)
off the asking price,..

Attic Roof Insulation
 

"Andy Champ" wrote in message
...
PCPaul wrote:
On Wed, 09 Jan 2008 20:21:34 +0000, Andy Champ wrote:

Dave Liquorice wrote:
On Tue, 8 Jan 2008 19:54:23 -0000, Michael Shergold wrote:

Have you investigated Renotherm? http://www.renotherm.co.uk/ I'd be
interested to hear if anyone has used this company or similar.
I wouldn't touch it with a barge pole.
If you put that into your loft I wouldn't buy your house.


OK, I'll bite. This stuff has been around now long enough to show any
bad effects - have any been seen in the flesh?

My (rented) place has the attic done like this. Seems OK so far, but
then again I don't know how long it's been in place...


I presume the issue is condensation/rot in the timbers?

I might be paranoid, and wrong, but I don't need to take the chance.

When this is on the inside of the tiles the condition of the timbers
cannot be assessed. It's been used because there is some kind of problem
with the roof, and it hides whatever the problem is. That's enough to
put me off.

Andy
Their website has a Q&A section that states
Q. Does Renotherm trap moisture in the roof timbers?
A. No, Renotherm does not absorb water but it does allow water vapour to
pass through the foam, at about the same rate as wood itself.

Q. Can alterations be made in the future?
A. Yes, the foam can be cut out and the tiles removed. Small areas can be
re-foamed with a Foamseal pack.

Michael