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John July 15th 10 12:08 AM

Sarking Felt
 
I have had a flue relocated and the tiles have been replaced - but I am left
with a ragged hole in the sarking felt.

Does it matter - if so, how can I minimise any problems?



harry July 15th 10 09:12 AM

Sarking Felt
 
On 14 July, 23:08, "John" wrote:
I have had a flue relocated and the tiles have been replaced - but I am left
with a ragged hole in the sarking felt.

Does it matter - if so, how can I minimise any problems?


It should have been fixed before the tiles were put on. There's not a
lot can be done now. If a tile cracks, water will come in the house.

1501 July 15th 10 09:12 AM

Sarking Felt
 
On 14 July, 23:08, "John" wrote:
how can I minimise any problems?


Call them back to finish the job off properly!

Tim Watts July 15th 10 10:21 AM

Sarking Felt
 
harry
wibbled on Thursday 15 July 2010 08:12

On 14 July, 23:08, "John" wrote:
I have had a flue relocated and the tiles have been replaced - but I am
left with a ragged hole in the sarking felt.

Does it matter - if so, how can I minimise any problems?


It should have been fixed before the tiles were put on. There's not a
lot can be done now. If a tile cracks, water will come in the house.


There must be a retro repair method surely?

I have a couple of holes in my felt (wasps and old vent pipe).

There's no way I'm taking tiles and battens off to "fix" this.

I know the basic method is to tuck some felt over the botton side of the
hole felt (ie between felt and tiles) and then teh top of teh repair section
goes under the felt at the top end of the hole.

That will divert some water should there be a leak.

Not sure what to do with the sides as the felt is damaged reight back to the
rafters. Foam it in perhaps?

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.


Rob[_27_] July 15th 10 11:23 AM

Sarking Felt
 
On 15/07/2010 08:12, harry wrote:
On 14 July, 23:08, wrote:
I have had a flue relocated and the tiles have been replaced - but I am left
with a ragged hole in the sarking felt.

Does it matter - if so, how can I minimise any problems?


It should have been fixed before the tiles were put on. There's not a
lot can be done now. If a tile cracks, water will come in the house.


I thought in such a case it would be preferable to fix the tile?

I've never fully understood sarking felt. Looks like some sort of ease
of constructing a roof expedient to me. If I was the OP I'd leave it and
be happy for the ventilation.

Rob

george [dicegeorge] July 15th 10 11:29 AM

Sarking Felt
 
On 15/07/10 10:23, Rob wrote:
On 15/07/2010 08:12, harry wrote:
On 14 July, 23:08, wrote:
I have had a flue relocated and the tiles have been replaced - but I
am left
with a ragged hole in the sarking felt.

Does it matter - if so, how can I minimise any problems?


It should have been fixed before the tiles were put on. There's not a
lot can be done now. If a tile cracks, water will come in the house.


I thought in such a case it would be preferable to fix the tile?

I've never fully understood sarking felt. Looks like some sort of ease
of constructing a roof expedient to me. If I was the OP I'd leave it and
be happy for the ventilation.

Rob

I think the main use of felt is to stop rain getting in when the
tiles/slates are off, and to stop draughts lifting off the slates/tiles.

But this never happened to my roof when I had no felt.

Felt means theres much less ventilation up there,
so more chance of condensation and woodrot.

But i'm a worrier with little experience.

When did they start felting roofs?
Have people had condensation problems?

There were reports here of condensation in the last very cold winter,
has the moisture cleared from people's attics over the last few warmer
months?

[g]

js.b1 July 15th 10 11:54 AM

Sarking Felt
 
Eh?

Sarking felt is a very beneficial development.
Realise a lost slate means you are getting water ingress from that
point to the ridge, not just that "small hole".
The problem with sarking felt is that it pools & rots at the bottom,
so eaves protectors are a good addition along with replacing the bit
of felt at the bottom.

Slate roof.
Slate fixings do fail eventually, if you lose a slate, the sarking
felt catches the rain and directs it into the gutter.

Marley single or double camber tiles.
The camber provides ventilation & wind driven rain ingress, the rain
runs down the sarking felt accordingly. They are really not a
brilliant roof tile yet were commonly used on a 22-degree roof with
sarking felt & close boarding (Scottish style).

Interlocking tiles.
Great in that water ingress is much reduced, good for very low angles
without close boarding.


Whoever did the chimney removal should have cut a piece of sarking
felt & overlapped correctly.

Did they vent the chimney stack if part of the wall is outside facing?
You do not want to vented into the loft & house, because it will
transfer moist air into the loft. You want an airbrick vent at the
top, at the bottom likewise or an internal vent. It does not need to
be big, but realise water will penetrate single brick and the chimney
can get running in water. Any joists tha abutt it will get rot in
their ends eventually, it can cause blown plaster issues.


Need Kipper At Sea to give a full answer, think he has retired.

george [dicegeorge] July 15th 10 12:38 PM

Sarking Felt
 
On 15/07/10 10:54, js.b1 wrote:
Eh?

Sarking felt is a very beneficial development.
Realise a lost slate means you are getting water ingress from that
point to the ridge, not just that "small hole".


But without felt I will notice the roof leak
when I'm checking the attic and see light or water
or when i see dampness on the ceiling
But with felt the leak could be undetected for years,
rotting the timbers down below.

And felt cuts ventilation drastically.

[g]


David WE Roberts[_2_] July 15th 10 12:47 PM

Sarking Felt
 

"george [dicegeorge]" wrote in message
...
On 15/07/10 10:23, Rob wrote:

snip
When did they start felting roofs?
Have people had condensation problems?

snip

I don't know when they started, but...

My 1896 house in rural Derbyshire didn't have felt (original slate roof, I
believe).
My 1930s house in Suffolk did have felt (again original tile roof, I think).

--
No plan survives contact with the enemy.

Helmuth von Moltke the Elder


Andrew Gabriel July 15th 10 07:14 PM

Sarking Felt
 
In article ,
Tim Watts writes:
harry
wibbled on Thursday 15 July 2010 08:12

On 14 July, 23:08, "John" wrote:
I have had a flue relocated and the tiles have been replaced - but I am
left with a ragged hole in the sarking felt.

Does it matter - if so, how can I minimise any problems?


It should have been fixed before the tiles were put on. There's not a
lot can be done now. If a tile cracks, water will come in the house.


There must be a retro repair method surely?

I have a couple of holes in my felt (wasps and old vent pipe).

There's no way I'm taking tiles and battens off to "fix" this.

I know the basic method is to tuck some felt over the botton side of the
hole felt (ie between felt and tiles) and then teh top of teh repair section
goes under the felt at the top end of the hole.

That will divert some water should there be a leak.

Not sure what to do with the sides as the felt is damaged reight back to the
rafters. Foam it in perhaps?


There's usually a slight sag on the felt between the rafters, and
this causes the water to run down the middle between rafters, which
is why you don't have to worry about the batten nail holes through
the felt into the rafters.

To be honest, I wouldn't bother repairing at this point. You could
do it if/when a leak happens.

Having said that, when I replaced part of my roof (a valley gutter),
I properly removed the battens and fitted new felt under the old,
but that's why I DIY - so I get a job done properly.

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

js.b1 July 15th 10 08:15 PM

Sarking Felt
 
On Jul 15, 11:38*am, "george [dicegeorge]"
wrote:
But without felt I will notice the roof leak


Yes, and you can usually find it more easily.

And felt cuts ventilation drastically.


It does greatly reduce ventilation to the loft, but the felt should
sag noticeably so as to provide good ventilation around the tiles. The
loft should be ventilated by "opposed" soffit vents to get cross-flow
air just like underfloors, but older houses often have chrysotile
soffit boards which lack vents.

george [dicegeorge] July 15th 10 09:29 PM

Sarking Felt
 
On 15/07/10 19:15, js.b1 wrote:
On Jul 15, 11:38 am, "george
wrote:
But without felt I will notice the roof leak


Yes, and you can usually find it more easily.

And felt cuts ventilation drastically.


It does greatly reduce ventilation to the loft, but the felt should
sag noticeably so as to provide good ventilation around the tiles. The
loft should be ventilated by "opposed" soffit vents to get cross-flow
air just like underfloors, but older houses often have chrysotile
soffit boards which lack vents.


Yes,
my house was ventilated through the slates
so now the roofers have felted it
I'm worrying about new ventilation routes.

[g]

Kipper at sea July 15th 10 11:01 PM

Sarking Felt
 
On Jul 15, 10:54*am, "js.b1" wrote:
Eh?

Sarking felt is a very beneficial development.
Realise a lost slate means you are getting water ingress from that
point to the ridge, not just that "small hole".
The problem with sarking felt is that it pools & rots at the bottom,
so eaves protectors are a good addition along with replacing the bit
of felt at the bottom.

Slate roof.
Slate fixings do fail eventually, if you lose a slate, the sarking
felt catches the rain and directs it into the gutter.

Marley single or double camber tiles.
The camber provides ventilation & wind driven rain ingress, the rain
runs down the sarking felt accordingly. They are really not a
brilliant roof tile yet were commonly used on a 22-degree roof with
sarking felt & close boarding (Scottish style).

Interlocking tiles.
Great in that water ingress is much reduced, good for very low angles
without close boarding.

Whoever did the chimney removal should have cut a piece of sarking
felt & overlapped correctly.

Did they vent the chimney stack if part of the wall is outside facing?
You do not want to vented into the loft & house, because it will
transfer moist air into the loft. You want an airbrick vent at the
top, at the bottom likewise or an internal vent. It does not need to
be big, but realise water will penetrate single brick and the chimney
can get running in water. Any joists tha abutt it will get rot in
their ends eventually, it can cause blown plaster issues.

Need Kipper At Sea to give a full answer, think he has retired.


Sarking felt or as its known now days as breather felt or underlay,
was first called Battiscloth in the early 1900. It was very heavy
fibre cloth strands with bitumen mixture coated in sawdust to stop it
from sticking together in the roll. Later they did away with the fibre
mixture and just use close string type net sprayed with bitumen with a
talc powder to prevent sticking in the roll, later they change the
talc to fine sand as the talc was classed as a health assured.
Felt did away with touching mortar. Touching mortar was cow hair mixed
with lime mortar and spread onto the roof lath and on the back of the
slates or tiles. The idea of felt was to form a draft and mainly a
vapour barrier. Most houses had a natural vent via the fireplace,
which most probably counteracted condensation. With the introduction
of central heating and loft insulation hence condensing on the
underside of the roof covering. Breather underlay is one way of
counteracting this problem, another way on older roofs is to use vent
tiles and vent ridge.

If there is a leak in the roof the water ingress is transferred to the
eave via the felt. It takes quite some time before the water comes
through the area where the actual leak is until the felt rots under
the area where the ingress is. Ponding is another problem with felt.
With most tiles or slates this is avoided by the use of “over fascia
felt support trays”. They are not ideal on plain tiles as the eave
tile batten is to low and tips them up and causes ponding. Ponding is
the term for the sag of the felt or underlay between the top of the
spar or rafter to the top of the fascia board.



Kipper at sea July 15th 10 11:09 PM

Sarking Felt
 
On Jul 15, 9:21*am, Tim Watts wrote:
harry
* wibbled on Thursday 15 July 2010 08:12

On 14 July, 23:08, "John" wrote:
I have had a flue relocated and the tiles have been replaced - but I am
left with a ragged hole in the sarking felt.


Does it matter - if so, how can I minimise any problems?


It should have been fixed before the tiles were put on. There's not a
lot can be done now. *If a tile cracks, water will come in the house.


There must be a retro repair method surely?

I have a couple of holes in my felt (wasps and old vent pipe).

There's no way I'm taking tiles and battens off to "fix" this.

I know the basic method is to tuck some felt over the botton side of the
hole felt (ie between felt and tiles) and then teh top of teh repair section
goes under the felt at the top end of the hole.

That will divert some water should there be a leak.

Not sure what to do with the sides as the felt is damaged reight back to the
rafters. Foam it in perhaps?

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.


When covering a removed chimney underlay should cover the area then
the battens and slates or tiles. A vent should be put in the
chimneystack in the outer wall below roof level and another at the
bottom of the stack to form a airflow

D.M.Chapman July 17th 10 10:25 AM

Sarking Felt
 
In article ,
David WE Roberts wrote:

My 1896 house in rural Derbyshire didn't have felt (original slate roof, I
believe).
My 1930s house in Suffolk did have felt (again original tile roof, I think).



My 1930s house in Kent doesn't have felt (original slate roof and a gale in
the loft :-))

Darren





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