counterflashing?
 

Our house is built of more-or-less solid cement blocks (c 1920, we
think.) It has a lower roof that butts against the main wall, which
joint I need to flash. My plan for the counterflashing is to cut a slot
along the blocks, to accept the 'top' of some rake edge, with the other
face of the rake laying down over the step flashing.

A single kerf fits the rake edge, but snuggly. I can go with that, and
bed the rake in (silicon?) caulking. Or, I can cut a wider slot
(1/4-1/2"), and bed the rake edge in mortar.

Any thoughts on the pros/cons would be appreciated.

Thanks,
George

counterflashing?
 

On Sat, 20 Aug 2011 17:13:34 -0400, George wrote:

Our house is built of more-or-less solid cement blocks (c 1920, we
think.) It has a lower roof that butts against the main wall, which
joint I need to flash. My plan for the counterflashing is to cut a slot
along the blocks, to accept the 'top' of some rake edge, with the other
face of the rake laying down over the step flashing.

A single kerf fits the rake edge, but snuggly. I can go with that, and
bed the rake in (silicon?) caulking. Or, I can cut a wider slot
(1/4-1/2"), and bed the rake edge in mortar.

Any thoughts on the pros/cons would be appreciated.

How clean of a slot can you make? I was thinking something along the lines of
rubber rope (think screen spline) to mechanically wedge the flashing, then use
the silicone to seal that in. ...just a thought from a DIYer.

counterflashing?
 

On Sat, 20 Aug 2011 16:35:00 -0500, "
wrote:

On Sat, 20 Aug 2011 17:13:34 -0400, George wrote:

Our house is built of more-or-less solid cement blocks (c 1920, we
think.) It has a lower roof that butts against the main wall, which
joint I need to flash. My plan for the counterflashing is to cut a slot
along the blocks, to accept the 'top' of some rake edge, with the other
face of the rake laying down over the step flashing.

A single kerf fits the rake edge, but snuggly. I can go with that, and
bed the rake in (silicon?) caulking. Or, I can cut a wider slot
(1/4-1/2"), and bed the rake edge in mortar.

Any thoughts on the pros/cons would be appreciated.

How clean of a slot can you make? I was thinking something along the lines of
rubber rope (think screen spline) to mechanically wedge the flashing, then use
the silicone to seal that in. ...just a thought from a DIYer.

I don't think there's room for a spline, even a thin one - the slot is
cut w/ a masonry blade on an angle grinder, so it's _mostly_ only as
thick as the blade. (There are places where it's less than perfect
straight, I have to say.) As far as wedging it, I have to cut about an
inch off the back of the embedded side of the rake. I plan to leave
tabs in that, and bend those over to wedge it in.

counterflashing?
 

On Sat, 20 Aug 2011 19:19:25 -0400, George wrote:

On Sat, 20 Aug 2011 16:35:00 -0500, "
wrote:

On Sat, 20 Aug 2011 17:13:34 -0400, George wrote:

Our house is built of more-or-less solid cement blocks (c 1920, we
think.) It has a lower roof that butts against the main wall, which
joint I need to flash. My plan for the counterflashing is to cut a slot
along the blocks, to accept the 'top' of some rake edge, with the other
face of the rake laying down over the step flashing.

A single kerf fits the rake edge, but snuggly. I can go with that, and
bed the rake in (silicon?) caulking. Or, I can cut a wider slot
(1/4-1/2"), and bed the rake edge in mortar.

Any thoughts on the pros/cons would be appreciated.

How clean of a slot can you make? I was thinking something along the lines of
rubber rope (think screen spline) to mechanically wedge the flashing, then use
the silicone to seal that in. ...just a thought from a DIYer.

I don't think there's room for a spline, even a thin one - the slot is
cut w/ a masonry blade on an angle grinder, so it's _mostly_ only as
thick as the blade. (There are places where it's less than perfect
straight, I have to say.) As far as wedging it, I have to cut about an
inch off the back of the embedded side of the rake. I plan to leave
tabs in that, and bend those over to wedge it in.

You mentioned cutting a wider slot but perhaps that's not such a good idea
now.

If I'm picturing your setup, you want to fold the tab over to wedge it in. The
folded tab would then expand and lock it into the block and resist pulling.
What you propose sounds like it'll work to hold the flashing. I was just
thinking about something a little stronger mechanically, so the silicone
wouldn't pull out. I'd use the silicone on the tab side (if I'm getting the
picture right) so it helps the wedge/tab hold. Let it set up before you bend
the flashing over.

counterflashing?
 

"George" wrote in message
...
Our house is built of more-or-less solid cement blocks (c 1920, we
think.) It has a lower roof that butts against the main wall, which
joint I need to flash. My plan for the counterflashing is to cut a slot
along the blocks, to accept the 'top' of some rake edge, with the other
face of the rake laying down over the step flashing.

A single kerf fits the rake edge, but snuggly. I can go with that, and
bed the rake in (silicon?) caulking. Or, I can cut a wider slot
(1/4-1/2"), and bed the rake edge in mortar.

Any thoughts on the pros/cons would be appreciated.

Thanks,
George

Clarify how you intend to cut along the block. You're not really thinking
of cutting into the block, are you?

counterflashing?
 

On Sat, 20 Aug 2011 22:04:42 -0400, "Mk" wrote:


"George" wrote in message
.. .
Our house is built of more-or-less solid cement blocks (c 1920, we
think.) It has a lower roof that butts against the main wall, which
joint I need to flash. My plan for the counterflashing is to cut a slot
along the blocks, to accept the 'top' of some rake edge, with the other
face of the rake laying down over the step flashing.

A single kerf fits the rake edge, but snuggly. I can go with that, and
bed the rake in (silicon?) caulking. Or, I can cut a wider slot
(1/4-1/2"), and bed the rake edge in mortar.

Any thoughts on the pros/cons would be appreciated.

Thanks,
George

Clarify how you intend to cut along the block. You're not really thinking
of cutting into the block, are you?

Yes. In fact, the first cut is already done. As noted, the blocks are
solid. Not cored.

counterflashing?
 

On Aug 20, 5:13*pm, George wrote:

Our house is built of more-or-less solid cement blocks (c 1920, we
think.) *It has a lower roof that butts against the main wall, which
joint I need to flash. *My plan for the counterflashing is to cut a slot
along the blocks, to accept the 'top' of some rake edge, with the other
face of the rake laying down over the step flashing.

A single kerf fits the rake edge, but snuggly. *I can go with that, and
bed the rake in (silicon?) caulking. *Or, I can cut a wider slot
(1/4-1/2"), and bed the rake edge in mortar.

Any thoughts on the pros/cons would be appreciated.

This is how it's supposed to be done:
http://www.van-mark.com/Roofing/UniP...oInstruct.html

The top bend 'barb' locks the flashing into the reglet (that's the
term for the slot you cut). Another way to lock it in place is to
roll up small pieces of flashing that will just fit into the reglet
with the counter flashing in place, and then use a cold chisel or old
screwdriver to push the little roll into place, with a hammer if
necessary. Everything gets caulked in place with polyurethane caulk.

R

counterflashing?
 

George wrote in :

Our house is built of more-or-less solid cement blocks (c 1920, we
think.) It has a lower roof that butts against the main wall, which
joint I need to flash. My plan for the counterflashing is to cut a slot
along the blocks, to accept the 'top' of some rake edge, with the other
face of the rake laying down over the step flashing.

A single kerf fits the rake edge, but snuggly. I can go with that, and
bed the rake in (silicon?) caulking. Or, I can cut a wider slot
(1/4-1/2"), and bed the rake edge in mortar.

Any thoughts on the pros/cons would be appreciated.

Thanks,
George

Sounds similar to flashing a chimney with flashing & counterflashing.
Your task is much simplier is my guess but cutting the groove is
discussed.

http://www.familyhandyman.com/DIY-Pr...g/Step-By-Step

Mortar will eat up aluminum flashing. Use polyurethane caulk. Not
silicone.