Long story short- roof is 65 feet across, 45 feet down the slope, very
shallow slope (perhaps too shallow), the lap joint that runs
horizontally across was done wrong years ago.

Previous owner's contractor ran the sealing tape above the screws
instead of below, so the water wicks up the joint and down the
screwholes. As a temp fix I've tried sealing the joint, but the joint
moves quite a bit with temp changes, so come spring I have to do a
more permanent fix.

I'd like to remove a section of the panels across the middle of the
roof (going horizontally) so I can fix some of the rotted plywood
that's under the joint. Then I'd add a new panel (under the upper
panel, over the lower) so it'd be 3 panels down the run of the roof
instead of 2. 65 feet worth of pulling screws from above the joint,
prying the metal up, sliding the panel underneath, putting on the
sealing tape, and screwing back down.
Seems pretty feasible except for the cut.

This would mean making 2 cuts (each 65 feet long) through the existing
roof panels, but how to make a cut like that that won't leave a jagged
edge, or cut through the plywood and into the trusses? I don't think
there's a 'neat' way to do it, pretty much would have to use a
circular saw with a fine-tooth carbide blade. Would go over it once
with the blade set 'deep' but just cutting the high parts (peaks) ___/
\___, then again with the blade set shallow to get the low parts.

I can punt and not replace the plywood (the weak section is quite
narrow), but I'm not sure I'll be able to get a good seal if I just
slide a new section of roofing under the uphill side, and over the
downhill side. Seems like having the roof 3 layers thick at the
existing lap joint might be problematic. That narrow horizontal strip
of roof won't hold a screw, either.

Yeah, I know, just have the 45-foot by 65-foot roof redone. Not in the
budget. Its an easy one though, only 1 penetration (masonry chimney),
and its the highest part of a shed-style roof. No peak, no wall
interface.

Maybe I need to pull the metal roof and do roll roofing- maybe the
pitch is too low even for a properly installed metal roof? Its about a
6 foot rise (or so) in 45 feet. 6/45, that's a 1 in 7.5.

Any ideas/strategies I'm overlooking?


Dave

On Dec 28, 8:24*pm, wrote:
Long story short- roof is 65 feet across, 45 feet down the slope, very
shallow slope (perhaps too shallow), the lap joint that runs
horizontally across was done wrong years ago.

Previous owner's contractor ran the sealing tape above the screws
instead of below, so the water wicks up the joint and down the
screwholes. As a temp fix I've tried sealing the joint, but the joint
moves quite a bit with temp changes, so come spring I have to do a
more permanent fix.

I'd like to remove a section of the panels across the middle of the
roof (going horizontally) so I can fix some of the rotted plywood
that's under the joint. Then I'd add a new panel (under the upper
panel, over the lower) so it'd be 3 panels down the run of the roof
instead of 2. 65 feet worth of pulling screws from above the joint,
prying the metal up, sliding the panel underneath, putting on the
sealing tape, and screwing back down.
Seems pretty feasible except for the cut.

This would mean making 2 cuts (each 65 feet long) through the existing
roof panels, but how to make a cut like that that won't leave a jagged
edge, or cut through the plywood and into the trusses? I don't think
there's a 'neat' way to do it, pretty much would have to use a
circular saw with a fine-tooth carbide blade. Would go over it once
with the blade set 'deep' but just cutting the high parts (peaks) ___/
\___, then again with the blade set shallow to get the low parts.

I can punt and not replace the plywood (the weak section is quite
narrow), but I'm not sure I'll be able to get a good seal if I just
slide a new section of roofing under the uphill side, and over the
downhill side. Seems like having the roof 3 layers thick at the
existing lap joint might be problematic. That narrow horizontal strip
of roof won't hold a screw, either.

Yeah, I know, just have the 45-foot by 65-foot roof redone. Not in the
budget. Its an easy one though, only 1 penetration (masonry chimney),
and its the highest part of a shed-style roof. No peak, no wall
interface.

Maybe I need to pull the metal roof and do roll roofing- maybe the
pitch is too low even for a properly installed metal roof? Its about a
6 foot rise (or so) in 45 feet. 6/45, that's a 1 in 7.5.

Any ideas/strategies I'm overlooking?

Dave

Just had an idea to simplify the cutting- make a jig for the saw from
some lumber that will guide the saw straight, and hold it a set height
above the panels so it can't overpenetrate, but can cut it all in one
shot.

Just thought of another downside- won't be able to properly re-
tarpaper the involved areas.


Dave

On Dec 28, 8:30�pm, wrote:
On Dec 28, 8:24�pm, wrote:





Long story short- roof is 65 feet across, 45 feet down the slope, very
shallow slope (perhaps too shallow), the lap joint that runs
horizontally across was done wrong years ago.

Previous owner's contractor ran the sealing tape above the screws
instead of below, so the water wicks up the joint and down the
screwholes. As a temp fix I've tried sealing the joint, but the joint
moves quite a bit with temp changes, so come spring I have to do a
more permanent fix.

I'd like to remove a section of the panels across the middle of the
roof (going horizontally) so I can fix some of the rotted plywood
that's under the joint. Then I'd add a new panel (under the upper
panel, over the lower) so it'd be 3 panels down the run of the roof
instead of 2. 65 feet worth of pulling screws from above the joint,
prying the metal up, sliding the panel underneath, putting on the
sealing tape, and screwing back down.
Seems pretty feasible except for the cut.

This would mean making 2 cuts (each 65 feet long) through the existing
roof panels, but how to make a cut like that that won't leave a jagged
edge, or cut through the plywood and into the trusses? I don't think
there's a 'neat' way to do it, pretty much would have to use a
circular saw with a fine-tooth carbide blade. Would go over it once
with the blade set 'deep' but just cutting the high parts (peaks) ___/
\___, then again with the blade set shallow to get the low parts.

I can punt and not replace the plywood (the weak section is quite
narrow), but I'm not sure I'll be able to get a good seal if I just
slide a new section of roofing under the uphill side, and over the
downhill side. Seems like having the roof 3 layers thick at the
existing lap joint might be problematic. That narrow horizontal strip
of roof won't hold a screw, either.

Yeah, I know, just have the 45-foot by 65-foot roof redone. Not in the
budget. Its an easy one though, only 1 penetration (masonry chimney),
and its the highest part of a shed-style roof. No peak, no wall
interface.

Maybe I need to pull the metal roof and do roll roofing- maybe the
pitch is too low even for a properly installed metal roof? Its about a
6 foot rise (or so) in 45 feet. 6/45, that's a 1 in 7.5.

Any ideas/strategies I'm overlooking?

Dave

Just had an idea to simplify the cutting- make a jig for the saw from
some lumber that will guide the saw straight, and hold it a set height
above the panels so it can't overpenetrate, but can cut it all in one
shot.

Just thought of another downside- won't be able to properly re-
tarpaper the involved areas.

Dave- Hide quoted text -

- Show quoted text -

how about roll rubber roofing glued well over the bad area, to stop
all future leaks. wouldnt fix damaged wood but perhaps its not critical

On Dec 28, 9:33Â*pm, " wrote:
On Dec 28, 8:30�pm, wrote:





On Dec 28, 8:24�pm, wrote:

Long story short- roof is 65 feet across, 45 feet down the slope, very
shallow slope (perhaps too shallow), the lap joint that runs
horizontally across was done wrong years ago.

Previous owner's contractor ran the sealing tape above the screws
instead of below, so the water wicks up the joint and down the
screwholes. As a temp fix I've tried sealing the joint, but the joint
moves quite a bit with temp changes, so come spring I have to do a
more permanent fix.

I'd like to remove a section of the panels across the middle of the
roof (going horizontally) so I can fix some of the rotted plywood
that's under the joint. Then I'd add a new panel (under the upper
panel, over the lower) so it'd be 3 panels down the run of the roof
instead of 2. 65 feet worth of pulling screws from above the joint,
prying the metal up, sliding the panel underneath, putting on the
sealing tape, and screwing back down.
Seems pretty feasible except for the cut.

This would mean making 2 cuts (each 65 feet long) through the existing
roof panels, but how to make a cut like that that won't leave a jagged
edge, or cut through the plywood and into the trusses? I don't think
there's a 'neat' way to do it, pretty much would have to use a
circular saw with a fine-tooth carbide blade. Would go over it once
with the blade set 'deep' but just cutting the high parts (peaks) ___/
\___, then again with the blade set shallow to get the low parts.

I can punt and not replace the plywood (the weak section is quite
narrow), but I'm not sure I'll be able to get a good seal if I just
slide a new section of roofing under the uphill side, and over the
downhill side. Seems like having the roof 3 layers thick at the
existing lap joint might be problematic. That narrow horizontal strip
of roof won't hold a screw, either.

Yeah, I know, just have the 45-foot by 65-foot roof redone. Not in the
budget. Its an easy one though, only 1 penetration (masonry chimney),
and its the highest part of a shed-style roof. No peak, no wall
interface.

Maybe I need to pull the metal roof and do roll roofing- maybe the
pitch is too low even for a properly installed metal roof? Its about a
6 foot rise (or so) in 45 feet. 6/45, that's a 1 in 7.5.

Any ideas/strategies I'm overlooking?

Dave

Just had an idea to simplify the cutting- make a jig for the saw from
some lumber that will guide the saw straight, and hold it a set height
above the panels so it can't overpenetrate, but can cut it all in one
shot.

Just thought of another downside- won't be able to properly re-
tarpaper the involved areas.

Dave- Hide quoted text -

- Show quoted text -

how about roll rubber roofing glued well over the bad area, to stop
all future leaks. wouldnt fix damaged wood but perhaps its not critical- Hide quoted text -

- Show quoted text -

I fear it'd be hard to get it to seal over all the little peaks, and
this joint moves a lot- I mean a lot. The metal panels are over 20
feet long, so there's a lot of expansion/contraction.

If I built up a little 'bump' or upwards loop in roll roofing to allow
for that, it'd build a pretty good dam, and because of the shallow
slope it'd back up a good distance, and start putting screws under
water with predictable results.


Dave