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Andy Burns August 21st 06 11:00 PM

roofing question
 
I checked the FAQ, and was surprised there seems to be no roofing
section ...

For the joint between a flat garage roof, and the upstand to the house
wall continuing above, what are the pros and cons of real lead flashing
v.s. the heavy duty self adhesive tape with a coat of primer on the wall?

To what depth should the pointing be raked out for the top edge of the
flashing/tape?

VisionSet August 22nd 06 12:09 AM

roofing question
 

"Andy Burns" wrote in message
...
I checked the FAQ, and was surprised there seems to be no roofing
section ...

For the joint between a flat garage roof, and the upstand to the house
wall continuing above, what are the pros and cons of real lead flashing
v.s. the heavy duty self adhesive tape with a coat of primer on the wall?


Lead lasts forever but is expensive, the other stuff is cheap but weak,
splits and comes unstuck.


To what depth should the pointing be raked out for the top edge of the
flashing/tape?


I've just redone the pointing and flashing on my chimneys and raked to 15mm
where the flashing is, which is about the original depth, but deeper the
better I guess.


--
Mike W



Dave Plowman (News) August 22nd 06 01:02 AM

roofing question
 
In article ,
Andy Burns wrote:
For the joint between a flat garage roof, and the upstand to the house
wall continuing above, what are the pros and cons of real lead flashing
v.s. the heavy duty self adhesive tape with a coat of primer on the wall?


Well, lead should last a lifetime and is *very* satisfying to work...

To what depth should the pointing be raked out for the top edge of the
flashing/tape?


With lead, enough to jam it in place securely before re-pointing, so about
an inch.

--
*A backward poet writes inverse.*

Dave Plowman London SW
To e-mail, change noise into sound.

Ken August 22nd 06 01:12 AM

roofing question
 
Round our way the seagulls love Flashband. They just peck away at it and rip
it off in shreds.

ken



Christian McArdle August 22nd 06 10:47 AM

roofing question
 
For the joint between a flat garage roof, and the upstand to the house
wall continuing above, what are the pros and cons of real lead flashing
v.s. the heavy duty self adhesive tape with a coat of primer on the wall?


The advantage of the lead is that it prevents water entering the building at
the join between the wall and roof. The stick on flash band does not have
this useful property.

Christian.



MikeH August 22nd 06 10:51 AM

roofing question
 

Go for the permanent solution - use lead. The stick-on stuff is
rubbish and always leaks in my experience, especially if it's in a
location that's exposed to the sun and the prevailing wind direction.

Mike


Andy Burns August 22nd 06 11:04 AM

roofing question
 
Christian McArdle wrote:

The advantage of the lead is that it prevents water entering the building


A quite desirable property, thanks to all who replied. I seem to be able
to get lead from sheds in 3m lengths, where my longest run will be
double that, anywhere sell longer? (then I might need a forklift to get
it up to the roof though)

If I stick with the 3m lengths, is an straight overlapped joint ok, or
better to aim for a wrap around like so?

--------------\ /------------
/--- | |
| ---/ |
\------/

nafuk August 22nd 06 11:46 AM

roofing question
 

Andy Burns wrote:
Christian McArdle wrote:

The advantage of the lead is that it prevents water entering the building


A quite desirable property, thanks to all who replied. I seem to be able
to get lead from sheds in 3m lengths, where my longest run will be
double that, anywhere sell longer? (then I might need a forklift to get
it up to the roof though)

If I stick with the 3m lengths, is an straight overlapped joint ok, or
better to aim for a wrap around like so?

--------------\ /------------
/--- | |
| ---/ |
\------/


Because of expansion max length should only be 1.5 m, with adjacent
section overlapping by 150mm.
Rake out to about 1". Insert length od lead and some approx 1" wide
rolls jammed in between the lead sheet and the top of raked out joint
(about 3 per length).
Cement in place.
If possible make the folds on the ground before inserting into raked
out joint as it is safer and gives a neater edge.


Christian McArdle August 22nd 06 11:48 AM

roofing question
 
If I stick with the 3m lengths, is an straight overlapped joint ok, or
better to aim for a wrap around like so?


I just overlapped mine, but put a small bulge in (about 5mm or so), so the
water would have to go uphill to run underneath. I also used a substantial
overlap. No sign of any water ingress.

Working with lead is great. It must be the nicest material I've ever used.
It cuts easily. It bends easily. It stays exactly where you put it.

One tip. Make sure you apply patination oil before installation. I generally
did, but forgot one piece, which does look significantly more manky than the
other bits.

You have the choice of sealing with mortar or lead silicone. I went with the
lead silicone as it is less work, as you don't have to mix up the mortar and
carry a bucket up there.

Christian.



John Rumm August 22nd 06 12:23 PM

roofing question
 
Andy Burns wrote:

A quite desirable property, thanks to all who replied. I seem to be able
to get lead from sheds in 3m lengths, where my longest run will be
double that, anywhere sell longer? (then I might need a forklift to get
it up to the roof though)


As others said, don't use runs of more than 6' to avoid expansion problems.

One useful trick I found: Having raked out a suitable groove to insert
the lead, you can use small strips of lead rolled up into a cylinder to
wedge into the grove every so often above the lead. This holds it firmly
in place before you apply the sealant or mortar.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

The Natural Philosopher August 22nd 06 06:17 PM

roofing question
 
Andy Burns wrote:
Christian McArdle wrote:

The advantage of the lead is that it prevents water entering the building


A quite desirable property, thanks to all who replied. I seem to be able
to get lead from sheds in 3m lengths, where my longest run will be
double that, anywhere sell longer? (then I might need a forklift to get
it up to the roof though)

If I stick with the 3m lengths, is an straight overlapped joint ok, or
better to aim for a wrap around like so?


Best is soldered, to me: However, when my lads were laying flashing,
THEY said that more than 1.5 meters should not be laid as a length as
expansion/contraction would rip it apart..since it was a sloping valley,
they simply overlapped it. I like the solution you have below though -
for a flat roof it should be good.

--------------\ /------------
/--- | |
| ---/ |
\------/


Dave Plowman (News) August 22nd 06 06:21 PM

roofing question
 
In article ,
John Rumm wrote:
One useful trick I found: Having raked out a suitable groove to insert
the lead, you can use small strips of lead rolled up into a cylinder to
wedge into the grove every so often above the lead. This holds it firmly
in place before you apply the sealant or mortar.


The usual way is a 'zig-zag' formation so you can make it any thickness.
Then tap in place with a drift which will open it out.

--
*Always remember you're unique, just like everyone else.

Dave Plowman London SW
To e-mail, change noise into sound.

Andy Burns August 23rd 06 02:05 AM

roofing question
 
Dave Plowman (News) wrote:

The usual way is a 'zig-zag' formation so you can make it any thickness.
Then tap in place with a drift which will open it out.


Fancy tackling that in ASCII art?


John Rumm August 23rd 06 04:42 AM

roofing question
 
Andy Burns wrote:

Dave Plowman (News) wrote:

The usual way is a 'zig-zag' formation so you can make it any thickness.
Then tap in place with a drift which will open it out.



Fancy tackling that in ASCII art?


Oh, easy:


\/\/\/\/\/\/\/\

;-)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/


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