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
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 . . . .
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
On Feb 23, 7:33 am, firstname.lastname@example.org wrote:
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
Just to clarify....the mansard is a fake. The real second floor wall
is framed directly over the lower floor wall. The mansard studding is
tapered 2x4s scabbed to the real wall studs at the top and with a
bottom plate nailed to the second floor subfloor at the lookout header.
Nope, but you could probably use some really long joist hangers if you
can find some. Really need to use 2x8s? I ask because it might be be
easier to find a joist hanger long enough if you used 2x6s. Probably
not code either but if you're not on the coast it's be ok.
On Feb 23, 12:26 pm, email@example.com wrote:
Actually, the reason I was thinking 2x8 was that then I could taper
the end that would fit up flush to the lookout joist at an angle to
give me the proper roof slope.
I'll have to sketch it up with actual sizes to see but I was thinking
that hangers for 2x12 could be used...I just didn't want to miss
something that some of the hardware manufactures might have conjured
up for something like this.
I just hate to start trying to set anchors in my bricks....the bricks
are quite hard, I know how much Portland cement was added to the
mortar, and I can see all sorts of grief coming from hammer drilling
up so close to the top...and for what....so I can use some joist
hangers on a ledger and be to code?
If all else fails, I'll sketch it up and take it in to the building
dept. guys and see what they say....I'll use an assumed name.
The other option (and it's looking better all the time) is to use an
insulated aluminum panel roof of the type used for manufactured
sunrooms...light, strong, and easy to do.
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