Framing Roof Joists For Addition When Top Plate Is Not Level

personalt

I am involved in a project where I am adding an additon to a ranch
house. House is about 25 feet wide about about 40 deep. Most of the
projects I work on are total gut jobs so I dont worry about saving
existing structure. However this house has a really good first with
new kitchens and baths so I want to keep from demoing the ceiling and
ceiling joists.

Joists go across house as expected. The top plate on the rght side of
house is about 1 inch lower then the left with a slight(1/2") pitch
toward the back.


I was wondering what methods others use to level the top plate before
adding a new floor in cases where the existing ceiling and ceiling
joists are to remain. In cases where I am am demoing the existing
celing joists and the slope isnt bad I sometimes shim under each
joist.


However for cases where I am leaving the existing ceiling joists (to
support exisiting drywall ceiling) and installing new joists I have
been doing is scribing and cutting the rim joist to follow the
contor. I like to install a rim joist because otherwise otherwise I
end up with a bunch of point loads which dont line up with the stud
wall(since the existing joists line up with the stud wall).


What I did in the past was a buy a engineered wood rim joist one size
over(assuming slope is less then 2 inches). I placed the enginnered
joist on the top plate temporally, shiming the low side until level.
I then ran a scribe down the outside of the building along the top
plate. This left me a line on the rim joist that followed the slope
of the top plate. I then trimmed it down with a circular saw so now
the contour of the rim joists makes the contor of the top plate.


This was time consuming but seems to work well. One thing that makes
it even mroe time consuming is the fact that the existing ceiling
joists in most cases extend flush to the edge of the top plate. This
causes me to have to cut these back 1 1/2 ". I then connect them to
the new rim joist with simpson angle brackets.


I was wondering how others do it when framing new floor joists in
parallel to existing when top plate isnt level.

TempestV

At one point I worked on a project where a second story was put on a log garage- the top of the logs was three inches out of level, so we set a level dryline at the level where the bottom of the top plate should go and used 2x4s on edge and set them to the line, and scribed them and cut them like you described. then we set 2 lines of 2x4 leveling blocks, on the inside of the wall and the outside, then set our top plates on top of the 2x4s. Of course we had to go to that trouble because there were 3 inches of difference from end to end, not half an inch. If it was only half an inch, we probably would have planned down one end of the top plate or shimmed underneath until it was level and go from there.

bigjax

I suspect that problems will arise when it comes time to do the siding job now that you have put the piece on a slant.Take a measure ment down from the soffit to the sill on both sides (solong as the soffit is`nt tilting ).Has any one taken a look at the sill on the home or perhaps if the foundation has settled.

tinner666

Have seen this before. When doing the siding, and there was a difference, we took measurements, then 'fudges' our lines to make the siding level. Seen deviations like that on a few new jobs for some reason.

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Frank Slate Roof Repairs, Richmond, Va.