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-   -   what is the fabric for under the roof tiles? (https://www.diybanter.com/uk-diy/214975-what-fabric-under-roof-tiles.html)

RobertL September 19th 07 11:02 AM

what is the fabric for under the roof tiles?
 

My house was built in the 1960s and like many it has heavy roof tiles
that are laid on battons which are fixed to the rafters. The tiles
seem to be held there by gravity alone - each one has a lip that
engages with the batton. Between the battons and the rafters is a
sheet of bituminous cloth (it looks like).

What is the purpose of this cloth?

Is it to stop the wind which might otherwise (1) blow water up the
tiles and into the roof space and (2) lift off the roof tiles? or it
is to catch any water that does leak in and guide it to the gutter.

I want to cut this cloth in order to remove as small patch of tiles so
I can do some ridge repairs without having to climb onto the outside
of the roof.

When I repair it afterwards does it need to be watertight or simply
windproof?

Thanks,

Robert


Andrew Mawson September 19th 07 12:04 PM

what is the fabric for under the roof tiles?
 

"RobertL" wrote in message
ups.com...

My house was built in the 1960s and like many it has heavy roof

tiles
that are laid on battons which are fixed to the rafters. The tiles
seem to be held there by gravity alone - each one has a lip that
engages with the batton. Between the battons and the rafters is a
sheet of bituminous cloth (it looks like).

What is the purpose of this cloth?

Is it to stop the wind which might otherwise (1) blow water up the
tiles and into the roof space and (2) lift off the roof tiles? or

it
is to catch any water that does leak in and guide it to the gutter.

I want to cut this cloth in order to remove as small patch of tiles

so
I can do some ridge repairs without having to climb onto the outside
of the roof.

When I repair it afterwards does it need to be watertight or simply
windproof?

Thanks,

Robert


It's called Sarking felt, and is there to stop rain and snow being
blown into the loft by an unfavourable wind. It also stops a load of
crud being blown in keeping the loft cleaner. Conventionally it is
laid from the roll parallel to the guttering, starting at the bottom
of the roof. Each subsequent strip being laid to over lap the previous
one by 4"-6". At the ridge, a roll is laid so that half goes down one
facet of the roof and the other half down the other facet. This gives
a waterproof seal so anything blowing under the tiles will run down
the outside of the sarking felt and down into the gutters, as the felt
should overlap the gutter board slightly and dip into the guttering.

You will find that the bituminous type will be very brittle by now and
will probably crumble as you try to remove it. Modern sarking felt is
a plastic sheeting, grey on one side and black on the other, with a
square nylon reinforcing mesh embedded between the layers.

Although you ought to be able to remove the tiles and felt, and do
your ridge repairs 'from inside' I cannot see how you can correctly
replace the sarking and tiles in a weatherproof fashion from inside.

If the tiles were laid correctly every third row should have been
nailed to the battens - or even every row if in an exposed position.

AWEM



RobertL September 19th 07 12:29 PM

what is the fabric for under the roof tiles?
 
On Sep 19, 11:04 am, "Andrew Mawson"
wrote:
"RobertL" wrote in message

ups.com...







My house was built in the 1960s and like many it has heavy roof

tiles
that are laid on battons which are fixed to the rafters. The tiles
seem to be held there by gravity alone - each one has a lip that
engages with the batton. Between the battons and the rafters is a
sheet of bituminous cloth (it looks like).


What is the purpose of this cloth?


Is it to stop the wind which might otherwise (1) blow water up the
tiles and into the roof space and (2) lift off the roof tiles? or

it
is to catch any water that does leak in and guide it to the gutter.


I want to cut this cloth in order to remove as small patch of tiles

so
I can do some ridge repairs without having to climb onto the outside
of the roof.


When I repair it afterwards does it need to be watertight or simply
windproof?


Thanks,


Robert


It's called Sarking felt, and is there to stop rain and snow being
blown into the loft by an unfavourable wind. It also stops a load of
crud being blown in keeping the loft cleaner. Conventionally it is
laid from the roll parallel to the guttering, starting at the bottom
of the roof. Each subsequent strip being laid to over lap the previous
one by 4"-6". At the ridge, a roll is laid so that half goes down one
facet of the roof and the other half down the other facet. This gives
a waterproof seal so anything blowing under the tiles will run down
the outside of the sarking felt and down into the gutters, as the felt
should overlap the gutter board slightly and dip into the guttering.

You will find that the bituminous type will be very brittle by now and
will probably crumble as you try to remove it. Modern sarking felt is
a plastic sheeting, grey on one side and black on the other, with a
square nylon reinforcing mesh embedded between the layers.

Although you ought to be able to remove the tiles and felt, and do
your ridge repairs 'from inside' I cannot see how you can correctly
replace the sarking and tiles in a weatherproof fashion from inside.

If the tiles were laid correctly every third row should have been
nailed to the battens - or even every row if in an exposed position.



that's very helpful. thank you.

You are right, the cloth is very crumbly now. in fact there is a
broken part elsewhere in the roof and the undersides of the tiles are
visible and that's how I found the tiles were apparently held only by
gravity. it could well be that some elsewhere are fixed down - I only
looked at one!

I want to replace, or repair, a cracked 'curved' ridge tile. It wa
spotted by workman replacing the barge boards. I though I might be
able to reach it as I described, but maybe its not so straightforward
in the light of your comments.

thanks again,

Robert



The Natural Philosopher September 19th 07 01:00 PM

what is the fabric for under the roof tiles?
 
RobertL wrote:
My house was built in the 1960s and like many it has heavy roof tiles
that are laid on battons which are fixed to the rafters. The tiles
seem to be held there by gravity alone - each one has a lip that
engages with the batton. Between the battons and the rafters is a
sheet of bituminous cloth (it looks like).

What is the purpose of this cloth?


To prevent wind lifting the tiles off, mainly.

It somewaht reduces sucton effects right by te tiles.


Is it to stop the wind which might otherwise (1) blow water up the
tiles and into the roof space and (2) lift off the roof tiles? or it
is to catch any water that does leak in and guide it to the gutter.


the former.

I want to cut this cloth in order to remove as small patch of tiles so
I can do some ridge repairs without having to climb onto the outside
of the roof.

When I repair it afterwards does it need to be watertight or simply
windproof?

Windproof. The tiles are the waterproof layer.

Thanks,

Robert


Rick Hughes September 19th 07 01:01 PM

what is the fabric for under the roof tiles?
 

"RobertL" wrote in message
ups.com...

My house was built in the 1960s and like many it has heavy roof tiles
that are laid on battons which are fixed to the rafters. The tiles
seem to be held there by gravity alone -



Well there is a mechanical fixing spec dependant on expected wind loading in
your area .. typically something like clip every other tile in every third
course, and clip all tiles in first course.


The felt is there to prevent snow & wind penetration, it is not there to
prevent water .. the lap on tiles takes care of that.

If you do remove felt, then make sure you slide patch under the row above
and have a good overlap. making sure at least 150mm on all side, and nailed
onto rafter, with large clout head galv felt nails.



keith_765 September 19th 07 04:06 PM

what is the fabric for under the roof tiles?
 

"The Natural Philosopher" wrote in message
...
RobertL wrote:
My house was built in the 1960s and like many it has heavy roof tiles
that are laid on battons which are fixed to the rafters. The tiles
seem to be held there by gravity alone - each one has a lip that
engages with the batton. Between the battons and the rafters is a
sheet of bituminous cloth (it looks like).

What is the purpose of this cloth?


To prevent wind lifting the tiles off, mainly.

What **** has told you "To prevent wind lifting the tiles off, mainly."

The main purpose is a vapour barrier, secondly it prevents the access in to
the roof space of driven snow and rain.
The only thing that prevent tiles from being sucked or blown off are the
nails use in the laying process. It used to be every third course in the
60s. Present specs its every other course on single interlocking tiles.
Double lap ties ( Rosemary type) every forth course.



Steve Rainbird September 19th 07 04:34 PM

what is the fabric for under the roof tiles?
 
"keith_765" wrote in message
...

"The Natural Philosopher" wrote in message
...
RobertL wrote:
My house was built in the 1960s and like many it has heavy roof tiles
that are laid on battons which are fixed to the rafters. The tiles
seem to be held there by gravity alone - each one has a lip that
engages with the batton. Between the battons and the rafters is a
sheet of bituminous cloth (it looks like).

What is the purpose of this cloth?


To prevent wind lifting the tiles off, mainly.

What **** has told you "To prevent wind lifting the tiles off, mainly."

The main purpose is a vapour barrier, secondly it prevents the access in
to
the roof space of driven snow and rain.
The only thing that prevent tiles from being sucked or blown off are the
nails use in the laying process. It used to be every third course in the
60s. Present specs its every other course on single interlocking tiles.
Double lap ties ( Rosemary type) every forth course.




Mine has holes in it in a few places. Should I repair these? If yes what
is the best way to do this?

--
Steve




keith_765 September 19th 07 10:58 PM

what is the fabric for under the roof tiles?
 

"Steve Rainbird" wrote in message
...
"keith_765" wrote in message
...

"The Natural Philosopher" wrote in message
...
RobertL wrote:
My house was built in the 1960s and like many it has heavy roof tiles
that are laid on battons which are fixed to the rafters. The tiles
seem to be held there by gravity alone - each one has a lip that
engages with the batton. Between the battons and the rafters is a
sheet of bituminous cloth (it looks like).

What is the purpose of this cloth?

To prevent wind lifting the tiles off, mainly.

What **** has told you "To prevent wind lifting the tiles off, mainly."

The main purpose is a vapour barrier, secondly it prevents the access in
to
the roof space of driven snow and rain.
The only thing that prevent tiles from being sucked or blown off are the
nails use in the laying process. It used to be every third course in the
60s. Present specs its every other course on single interlocking tiles.
Double lap ties ( Rosemary type) every forth course.




Mine has holes in it in a few places. Should I repair these? If yes what
is the best way to do this?

--
Steve

Self adhesive Flash Band from the inside the roof space.



Steve Rainbird September 20th 07 12:16 AM

what is the fabric for under the roof tiles?
 
"keith_765" wrote in message
...

"Steve Rainbird" wrote in message
...
"keith_765" wrote in message
...

"The Natural Philosopher" wrote in message
...
RobertL wrote:
My house was built in the 1960s and like many it has heavy roof
tiles
that are laid on battons which are fixed to the rafters. The tiles
seem to be held there by gravity alone - each one has a lip that
engages with the batton. Between the battons and the rafters is a
sheet of bituminous cloth (it looks like).

What is the purpose of this cloth?

To prevent wind lifting the tiles off, mainly.

What **** has told you "To prevent wind lifting the tiles off,
mainly."

The main purpose is a vapour barrier, secondly it prevents the access
in
to
the roof space of driven snow and rain.
The only thing that prevent tiles from being sucked or blown off are
the
nails use in the laying process. It used to be every third course in
the
60s. Present specs its every other course on single interlocking tiles.
Double lap ties ( Rosemary type) every forth course.




Mine has holes in it in a few places. Should I repair these? If yes
what
is the best way to do this?

--
Steve

Self adhesive Flash Band from the inside the roof space.



Cheers I will look into that.



--
Steve





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