DIYbanter

DIYbanter (https://www.diybanter.com/)
-   UK diy (https://www.diybanter.com/uk-diy/)
-   -   Slate Roof With No Underfelt - A Problem?? (https://www.diybanter.com/uk-diy/4961-slate-roof-no-underfelt-problem.html)

SuzySue January 8th 04 07:52 AM

Slate Roof With No Underfelt - A Problem??
 
If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.

nick nelson January 8th 04 09:44 AM

Slate Roof With No Underfelt - A Problem??
 


SuzySue wrote:
If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.


In my experience, this is perfectly usual in older houses
and doesn't constitute a problem at all.

Nick


Grunff January 8th 04 09:48 AM

Slate Roof With No Underfelt - A Problem??
 
SuzySue wrote:

If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.



Our roof (1930s) isn't felted. It's not a problem except where there are
gaps in the slates. When we replace the roof (probably this year) we
will felt it.

--
Grunff

Tony January 8th 04 09:53 AM

Slate Roof With No Underfelt - A Problem??
 
SuzySue wrote:

If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.

It is certainly not unusual to get roofs like this, especially in the
North. The consensus seems to be that the lack of weatherproofness is
offset by the excellent ventilation (which quickly dries out any water
or snow that does blow in)! The roof space will also be pretty dirty.

I would say that if the roof looks in good condition (i.e. no broken or
displaced slates, no rotten or broken timbers) then this is not a major
problem. If you do need it doing, it is not normally hugely expensive
(maybe a couple of thousand pounds?).
tony


Andy Hall January 8th 04 10:05 AM

Slate Roof With No Underfelt - A Problem??
 
On 7 Jan 2004 23:52:24 -0800, (SuzySue)
wrote:

If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.


It's very common indeed in older properties and is not a problem in
itself. Having felt provides a second line of defence in case a
slips out of place. Not having it means that you need to be a bit
more vigilant with keeping an eye on the roof from the outside and the
inside, since a slipped slate may mean water starting to come in.
Even then, if it is only one slate, the overlapping of the slates
would mean that that is not usually a major issue for a few days until
it can be fixed.

If the roof is in generally good condition, then it is reasonable to
leave it alone. On the other hand if the slates appear crumbly at the
edges or if you experience a lot of them slipping because the nails
have rusted, then it can make sense to have the roof relaid. This
involves taking the lot off, and the battens and then laying felt,
battens, probably re-using some slates and replacing others with
second hand good slates.

I would see what happens over the course of a year or so and then
decide. Obviously if there are any signs of water coming in or
slipped slates, these should be fixed.




..andy

To email, substitute .nospam with .gl

Andrew Gabriel January 8th 04 10:22 AM

Slate Roof With No Underfelt - A Problem??
 
In article ,
(SuzySue) writes:
If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.


No. It's something you would address if you needed to refit the slates
for some other reason though.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.


Houses designed and built that way have survived hundreds of years,
so of itself, it can't be considered "urgent". Repairing a leaking
roof would be urgent though, e.g. if an unlined roof has misaligned
or missing slates.

--
Andrew Gabriel

Dave Liquorice January 8th 04 10:31 AM

Slate Roof With No Underfelt - A Problem??
 
On 7 Jan 2004 23:52:24 -0800, SuzySue wrote:

If a terraced house had a slate roof with no underfelt, would this
be something that most people would want fixed immediately


If the slates are in good condition and well fixed then it's not a
problem at all. Once a slate slips though it needs to be attended to
with rather more urgency than on a roof with sarking.

Without sarking the roof space will probably be dirtier as windblown
atmospheric fallout (dust) will find it's way in. Stored items will
need dust sheets over them.

--
Cheers
Dave. pam is missing e-mail




N. Thornton January 8th 04 11:27 AM

Slate Roof With No Underfelt - A Problem??
 
(SuzySue) wrote in message . com...
If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.


Hi Susan: neither, it can be lived with indefinately. All original
Victorian slate roofs are feltless.

There are 2 minor caveats with unfelted roofs:

1. Theyre almost always very old and the occasional slate will
probably drop off and need refixing. Budget maybe £30 a year.
2. They let water wind and dust in, the wind dries out the water no
problem. It just means you cant use wind blocking insulation up
against the woodwork, as it would trap water.

If youre buying one, look at the slates, replace any broken ones,
refit fallen ones. And if the roof has more than about 25% of slates
fixed with visible metal tabs its time to consider reroofing.

There are lots of unfelted roofs still working without any problem.


Regards, NT

Alan James January 8th 04 12:08 PM

Slate Roof With No Underfelt - A Problem??
 

"SuzySue" wrote in message
om...
If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.


Not a problem and anyway the slates have a much longer life than felt which
was installed in the past. My slate roof has wooden sarking. When I
installed some Velux windows I found the sarking was in perfect condition
after 100 years. One problem you may come across is that surveyors will
report seeing daylight. Possibly a true report but worthless without
qualification which it never is. Its the through ventilation which keeps
the roof timbers dry something some BCOs fail to recognise also when
insisiting on roof vents.

Alan



The Natural Philosopher January 8th 04 05:15 PM

Slate Roof With No Underfelt - A Problem??
 
SuzySue wrote:

If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.


Actaually the felt does eff all. Its there to stop the slates being
blown off.

It does make the rough moree draughty even than a building inspectors
mandatory eaves vents though, so you might rather want to insulate
counter batten, insulate and board out the loft for snugness...

MUCVH better bang for your buck than re-felting.

Of couse, if the roof ever needs redoing in toto, by all menas felt it.
Its not expensive.


SuzySue January 10th 04 04:01 PM

Slate Roof With No Underfelt - A Problem??
 
Out of curiosity, from what year/decade was underfelt commonly used
underneath roof slates?

Ed Sirett January 11th 04 01:07 AM

Slate Roof With No Underfelt - A Problem??
 
On Sat, 10 Jan 2004 08:01:24 +0000, SuzySue wrote:

Out of curiosity, from what year/decade was underfelt commonly used
underneath roof slates?


I would have said it was about the vintage as cavity walls so increasingly
from 1915 to universally by 1940.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html



SuzySue January 11th 04 01:06 PM

Slate Roof With No Underfelt - A Problem??
 

I would have said it was about the vintage as cavity walls so increasingly
from 1915 to universally by 1940.


Thanks very much guys for all above info. Much appreciated!

Andrew January 13th 04 10:36 PM

Slate Roof With No Underfelt - A Problem??
 
In article , Grunff
writes
SuzySue wrote:

If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.



Our roof (1930s) isn't felted. It's not a problem except where there are
gaps in the slates. When we replace the roof (probably this year) we
will felt it.

Hopefully with a breathable membrane and not 'felt' (old-fashioned?)


--
Andrew

PJO January 15th 04 02:25 PM

Slate Roof With No Underfelt - A Problem??
 

Well it's not been urgent all these years has it?!

Providing the roof is intact and straight consider a foam type under tile
job. That will insulate and hold everything in place BUT is a bitch if you
ever do need to remove a slate cos it effectively glues them all together.



"Andrew" wrote in message
...
In article , Grunff
writes
SuzySue wrote:

If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and something
which can be lived with i.e. not usually considered an "urgent"
problem.



Our roof (1930s) isn't felted. It's not a problem except where there are
gaps in the slates. When we replace the roof (probably this year) we
will felt it.

Hopefully with a breathable membrane and not 'felt' (old-fashioned?)


--
Andrew




L Reid January 15th 04 07:02 PM

Slate Roof With No Underfelt - A Problem??
 
"Andrew" wrote in message
...
In article , Grunff
writes
SuzySue wrote:

If a terraced house had a slate roof with no underfelt, would this be
something that most people would want fixed immediately i.e. taking
off all the slates, and installing underfelt and replacing all the
slates again.

Or is having no underfelt on a roof not a major problem, and

something
which can be lived with i.e. not usually considered an "urgent"
problem.


Our roof (1930s) isn't felted. It's not a problem except where there

are
gaps in the slates. When we replace the roof (probably this year) we
will felt it.

Hopefully with a breathable membrane and not 'felt' (old-fashioned?)


--
Andrew




Our new (to us, built 1880) house doesn't have felt, and others in the same
street have had problems after felting theirs due to lack of ventilation to
the roof members. one thing about not having felt is there's plenty of space
for air to get in and dry things out. If the house was built without one,
just keep an eye out for missing tiles in high winds. If it originally had
one though, I'd be inclined to get it re-felted pretty quickly.



N. Thornton January 16th 04 12:15 AM

Slate Roof With No Underfelt - A Problem??
 
"PJO" wrote in message ...
Well it's not been urgent all these years has it?!

Providing the roof is intact and straight consider a foam type under tile
job. That will insulate and hold everything in place BUT is a bitch if you
ever do need to remove a slate cos it effectively glues them all together.


Dont even think about it.

Regards, NT

PJO January 16th 04 09:29 AM

Slate Roof With No Underfelt - A Problem??
 

"N. Thornton" wrote in message
om...
"PJO" wrote in message

...
Well it's not been urgent all these years has it?!

Providing the roof is intact and straight consider a foam type under

tile
job. That will insulate and hold everything in place BUT is a bitch if

you
ever do need to remove a slate cos it effectively glues them all

together.

Dont even think about it.

Regards, NT


Why not?

I used it on a property and not only did it save me a load of time and money
it also saved the roof!



Dave Plowman January 16th 04 10:31 AM

Slate Roof With No Underfelt - A Problem??
 
In article ,
PJO wrote:
Providing the roof is intact and straight consider a foam type under
tile job. That will insulate and hold everything in place BUT is a
bitch if you ever do need to remove a slate cos it effectively glues
them all together.


Dont even think about it.


Why not?


I used it on a property and not only did it save me a load of time and
money it also saved the roof!


For a short time, possibly. But removing ventilation from the rafters etc
will almost certainly cause long term problems. It also prevents easy
inspection for leaks.

--
*There are 3 kinds of people: those who can count & those who can't.

Dave Plowman London SW 12
RIP Acorn

Dave Liquorice January 16th 04 11:02 AM

Slate Roof With No Underfelt - A Problem??
 
On Fri, 16 Jan 2004 09:29:36 -0000, PJO wrote:

Providing the roof is intact and straight consider a foam type
under tile job. That will insulate and hold everything in place
BUT is a bitch if you ever do need to remove a slate cos it
effectively glues them all together.


Dont even think about it.


Why not?


Well you quote one reason yourself, when (not if) the roof needs
repairing it won't be a straight forward job and you won't be able to
reuse any of the slates.

The of course when (not if) water does penetrate the slates it can't
dry out quickly and thus increases the chances that the rafters and/or
laths are going to rot.

I used it on a property and not only did it save me a load of time
and money it also saved the roof!


In the short term, yes. But when the roof finally fails it will be a
much bigger and longer job thus more expensive.

--
Cheers
Dave. pam is missing e-mail




Belinda January 16th 04 12:03 PM

Slate Roof With No Underfelt - A Problem??
 
i've had spray foam on mine now for 10 years and it is fine.
no more slipped tiles, a very warm useable roof space
reduced heating costs
and no condensation that people that don't know scare people with.


Dave Liquorice wrote:

On Fri, 16 Jan 2004 09:29:36 -0000, PJO wrote:

Providing the roof is intact and straight consider a foam type
under tile job. That will insulate and hold everything in place
BUT is a bitch if you ever do need to remove a slate cos it
effectively glues them all together.

Dont even think about it.


Why not?


Well you quote one reason yourself, when (not if) the roof needs
repairing it won't be a straight forward job and you won't be able to
reuse any of the slates.

The of course when (not if) water does penetrate the slates it can't
dry out quickly and thus increases the chances that the rafters and/or
laths are going to rot.

I used it on a property and not only did it save me a load of time
and money it also saved the roof!


In the short term, yes. But when the roof finally fails it will be a
much bigger and longer job thus more expensive.

--
Cheers
Dave. pam is missing e-mail



Andy Hall January 16th 04 01:02 PM

Slate Roof With No Underfelt - A Problem??
 
On Fri, 16 Jan 2004 12:03:46 +0000 (UTC), Belinda
wrote:

i've had spray foam on mine now for 10 years and it is fine.
no more slipped tiles, a very warm useable roof space
reduced heating costs
and no condensation that people that don't know scare people with.


I hope you don't ever want to sell it........
..andy

To email, substitute .nospam with .gl

Dave Plowman January 16th 04 01:24 PM

Slate Roof With No Underfelt - A Problem??
 
In article ,
Belinda wrote:
i've had spray foam on mine now for 10 years and it is fine.
no more slipped tiles, a very warm useable roof space
reduced heating costs
and no condensation that people that don't know scare people with.


So in another few years be prepared for *total* replacement of the entire
roof structure - or if you sell, a survey giving a negative report.

Roof timbers *need* to be ventilated on all sides - if you look at a new
roof you'll see ventilators fitted. Older roofs will allow enough airflow
without.

--
*Growing old is inevitable, growing up is optional

Dave Plowman London SW 12
RIP Acorn

Tony Bryer January 16th 04 03:56 PM

Slate Roof With No Underfelt - A Problem??
 
In article , Dave Plowman
wrote:
Roof timbers *need* to be ventilated on all sides - if you
look at a new roof you'll see ventilators fitted. Older roofs
will allow enough airflow without.


I'm not about to be persuaded that spraying roof timbers with
foam is a good idea, but the key reason roof spaces are
ventilated is because the insulation is at ceiling level, the
roof space is therefore very cold and condensation on the
timber is likely without adequate ventilation. If you move the
insulation to rafter level the air in the loft space is that
much warmer and the risk of condensation substantially reduced.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser
http://www.sda.co.uk/qsedbuk.htm



N. Thornton January 16th 04 05:37 PM

Slate Roof With No Underfelt - A Problem??
 
"Dave Liquorice" wrote in message .1...
On Fri, 16 Jan 2004 09:29:36 -0000, PJO wrote:


Providing the roof is intact and straight consider a foam type
under tile job. That will insulate and hold everything in place
BUT is a bitch if you ever do need to remove a slate cos it
effectively glues them all together.


Dont even think about it.


Why not?


Well you quote one reason yourself, when (not if) the roof needs
repairing it won't be a straight forward job and you won't be able to
reuse any of the slates.

The of course when (not if) water does penetrate the slates it can't
dry out quickly and thus increases the chances that the rafters and/or
laths are going to rot.


I used it on a property and not only did it save me a load of time
and money it also saved the roof!


In the short term, yes. But when the roof finally fails it will be a
much bigger and longer job thus more expensive.


Yes. Slate roofs are not watertight, the beams will get wet, and water
will stay there. That would be a worrying scenario.


Regards, NT

Dave Plowman January 16th 04 05:57 PM

Slate Roof With No Underfelt - A Problem??
 
In article ,
Tony Bryer wrote:
I'm not about to be persuaded that spraying roof timbers with
foam is a good idea, but the key reason roof spaces are
ventilated is because the insulation is at ceiling level, the
roof space is therefore very cold and condensation on the
timber is likely without adequate ventilation. If you move the
insulation to rafter level the air in the loft space is that
much warmer and the risk of condensation substantially reduced.


But increased on those parts of the rafters etc above the foam?

--
*Dance like nobody's watching.

Dave Plowman London SW 12
RIP Acorn


All times are GMT +1. The time now is 09:12 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter