Shed roof over porch

Posted by cavedweller on February 22, 2009, 2:35 pm

I have a 7'D x14'W concrete porch over which I would like to construct
an almost flat roof (pitched about 1"/ft down the 7' depth.) The
house wall is brick veneer. The second floor joists are 2x10 16" OC
and extend out to a 2x!0 header to carry the mansard wall and form a
16" soffit covered with 3/4" ply.

2x8 joisting, fully supported with posts at the outer end, would do it
but rather than drill into the brick and then bolt on a ledger on the
brick and use joist hangers, I wondered about hanging the roof joists
from the second floor lookouts (after removing the soffit), perhaps
using simply a large-enough joist hanger (or two) with the nailing
flanges bent flat, or some other piece of hardware that I've yet to
discover.

Thoughts?

Posted by DanG on February 22, 2009, 6:29 pm

That would actually be a better solution than tagging on the brick
veneer. I assume the mansard is covered in a roofing material
like 3 tab shingles. Open the soffit and take the porch rafters
all the way back to the stud wall if possible, even cutting them
to bear on the double plate. This would allow a good flashing
solution from the existing mansard to the new flat roof. It will
probably require removing one or two courses of mansard shingles
to insure a real good tie-in and a premium flat roof material.

--
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)
dgriff237@7cox.net

>I have a 7'D x14'W concrete porch over which I would like to
>construct
> an almost flat roof (pitched about 1"/ft down the 7' depth.)
> The
> house wall is brick veneer. The second floor joists are 2x10
> 16" OC
> and extend out to a 2x!0 header to carry the mansard wall and
> form a
> 16" soffit covered with 3/4" ply.
> 2x8 joisting, fully supported with posts at the outer end, would
> do it
> but rather than drill into the brick and then bolt on a ledger
> on the
> brick and use joist hangers, I wondered about hanging the roof
> joists
> from the second floor lookouts (after removing the soffit),
> perhaps
> using simply a large-enough joist hanger (or two) with the
> nailing
> flanges bent flat, or some other piece of hardware that I've yet
> to
> discover.
> Thoughts?
>

Posted by cavedweller on February 22, 2009, 6:57 pm

> That would actually be a better solution than tagging on the brick
> veneer. =A0I assume the mansard is covered in a roofing material
> like 3 tab shingles. =A0Open the soffit and take the porch rafters
> all the way back to the stud wall if possible, even cutting them
> to bear on the double plate. =A0This would allow a good flashing
> solution from the existing mansard to the new flat roof. =A0It will
> probably require removing one or two courses of mansard shingles
> to insure a real good tie-in and a premium flat roof material.

24" cedar shakes with 10" exposure. 3' heavy felt at the bottom of
the mansard
over the plywood sheathing. All courses interleaved with 15# paper
all the way to
the top. I can get flashing up under the first course to the first
nailing line, which
would be 10" plus a couple. I don't want to touch the shakes.

You understand that I'm talking about the new porch roof joists
sitting directly beneath
the lookout 2x10s...not beside them? The bricks reach as high as the
top of the double
plate in the first floor wall so it would be difficult to get to the
top plate. Besides, the
lookouts already sit on. and are attached to, the top plate and extend
into the house to
the next partition wall about 14' away.

I want the roof deck to end up just an inch below the drip edge on the
mansard.

Posted by on February 23, 2009, 7:33 am

lly be a better solution than tagging on the brick

> > veneer. =A0I assume the mansard is covered in a roofing material
> > like 3 tab shingles. =A0Open the soffit and take the porch rafters
> > all the way back to the stud wall if possible, even cutting them
> > to bear on the double plate. =A0This would allow a good flashing
> > solution from the existing mansard to the new flat roof. =A0It will
> > probably require removing one or two courses of mansard shingles
> > to insure a real good tie-in and a premium flat roof material.

> 24" cedar shakes with 10" exposure. =A03' heavy felt at the bottom of
> the mansard
> over the plywood sheathing. =A0All courses interleaved with 15# paper
> all the way to
> the top. =A0I can get flashing up under the first course to the first
> nailing line, which
> would be 10" plus a couple. =A0I don't want to touch the shakes.
> You understand that I'm talking about the new porch roof joists
> sitting directly beneath
> the lookout 2x10s...not beside them? =A0The bricks reach as high as the
> top of the double
> plate in the first floor wall so it would be difficult to get to the
> top plate. =A0Besides, the
> lookouts already sit on. and are attached to, the top plate and extend
> into the house to
> the next partition wall about 14' away.
> I want the roof deck to end up just an inch below the drip edge on the
> mansard.

Why not go ahead and cut the existing roof back and join the new roof
directly to it? Sounds like it would give you a little more headroom
as well.

Posted by cavedweller on February 23, 2009, 8:21 am

On Feb 23, 7:33=A0am, jamesgan...@gmail.com wrote:
ually be a better solution than tagging on the brick

> > > veneer. =A0I assume the mansard is covered in a roofing material
> > > like 3 tab shingles. =A0Open the soffit and take the porch rafters
> > > all the way back to the stud wall if possible, even cutting them
> > > to bear on the double plate. =A0This would allow a good flashing
> > > solution from the existing mansard to the new flat roof. =A0It will
> > > probably require removing one or two courses of mansard shingles
> > > to insure a real good tie-in and a premium flat roof material.

> > 24" cedar shakes with 10" exposure. =A03' heavy felt at the bottom of
> > the mansard
> > over the plywood sheathing. =A0All courses interleaved with 15# paper
> > all the way to
> > the top. =A0I can get flashing up under the first course to the first
> > nailing line, which
> > would be 10" plus a couple. =A0I don't want to touch the shakes.
> > You understand that I'm talking about the new porch roof joists
> > sitting directly beneath
> > the lookout 2x10s...not beside them? =A0The bricks reach as high as the
> > top of the double
> > plate in the first floor wall so it would be difficult to get to the
> > top plate. =A0Besides, the
> > lookouts already sit on. and are attached to, the top plate and extend
> > into the house to
> > the next partition wall about 14' away.
> > I want the roof deck to end up just an inch below the drip edge on the
> > mansard.

> Why not go ahead and cut the existing roof back and join the new roof
> directly to it? =A0Sounds like it would give you a little more headroom
> as well.

Gee, I guess there really is a lot wrong with the clarity of my first
post and with the second as well. I asked about hanging joists from
some lookout joists with appropriate hardware....do you know of such
hardware?

Page 1 of 2 1 2 > last >>

Similar Threads	Posted
Expanding shed roof.	March 9, 2007, 9:30 am
12x16 shed roof ridge beam	April 29, 2007, 10:16 pm
Correct Beam Spacing for Shed Roof	February 26, 2009, 9:54 am
Correct Beam Spacing for Shed Roof	February 26, 2009, 10:17 am
Creating a gable roof out of a mansard roof	July 20, 2006, 5:03 pm
shed foundations	August 18, 2007, 6:45 am
Shed on a slope	July 25, 2008, 7:45 am
Footings for Shed	April 15, 2009, 10:17 am
Raising a large shed (20 x 24)	January 31, 2008, 8:54 am
Building a small shed	July 20, 2008, 8:30 am