StrucPatholgst
Structural
- Jan 23, 2013
- 156
The Scenario:
Tiny 1890's balloon frame, narrow floor plan (11' wide, 32' deep) with a shallow 7 foot 'L' leg at the rear (so if I type the letter 'L', the street is at the top of the L). Racking damage (leaning to the side of the 'L' to the right), likely from the Great Atlantic hurricane in '44. Top of foundation is level all around perimeter, and in good condition. Sill beam in excellent condition. Floors generally level, save for 3/4" age-related wood creep. Home apparently received a full gut and exterior reno in the 80's that completely concealed the racking. Current owner started a full gut reno, and revealed it all over again. Original racking is on the order of 6 inches over the full two story height. All of the current doors and windows are plumb (windows have 2004 date code). 1980's era drywall at left and right facades is out of plumb 3/4" over heights of rooms at both stories. Owner wants to remove one wall between kitchen and front room. Secondary issue of ridiculous ad hoc stud patterns at second floor right side wall, where the builder used up all of his shorts to complete the framing to the top of the second floor (real clown act).
The Game Plan:
Easier to install full shear panels at front and rear facades than to break it up, so that's what's going in. Panels also going in at street side of 'L' bump out (both floors), and at the stairwell short walls on floors 1 and 2 and the basement. Installing continuous 2x lumber to simulate a rim joist at each of these walls, screwed to the studs above the drywall line, and doubling up corner studs through the transitions between floors with LVL studs. Installing straps every 8 feet from first floor studs down to interior face of foundation (no sill anchors to speak of). Reinforcing the section of ad hoc 'shorts' framing at second floor with new sister studs.
This was an interesting exercise, because the floor plan is so small that it was a waste of labor to fab shear wall panels to the minimum requirement, as opposed to just installing full sheets and calling it a day.
Tiny 1890's balloon frame, narrow floor plan (11' wide, 32' deep) with a shallow 7 foot 'L' leg at the rear (so if I type the letter 'L', the street is at the top of the L). Racking damage (leaning to the side of the 'L' to the right), likely from the Great Atlantic hurricane in '44. Top of foundation is level all around perimeter, and in good condition. Sill beam in excellent condition. Floors generally level, save for 3/4" age-related wood creep. Home apparently received a full gut and exterior reno in the 80's that completely concealed the racking. Current owner started a full gut reno, and revealed it all over again. Original racking is on the order of 6 inches over the full two story height. All of the current doors and windows are plumb (windows have 2004 date code). 1980's era drywall at left and right facades is out of plumb 3/4" over heights of rooms at both stories. Owner wants to remove one wall between kitchen and front room. Secondary issue of ridiculous ad hoc stud patterns at second floor right side wall, where the builder used up all of his shorts to complete the framing to the top of the second floor (real clown act).
The Game Plan:
Easier to install full shear panels at front and rear facades than to break it up, so that's what's going in. Panels also going in at street side of 'L' bump out (both floors), and at the stairwell short walls on floors 1 and 2 and the basement. Installing continuous 2x lumber to simulate a rim joist at each of these walls, screwed to the studs above the drywall line, and doubling up corner studs through the transitions between floors with LVL studs. Installing straps every 8 feet from first floor studs down to interior face of foundation (no sill anchors to speak of). Reinforcing the section of ad hoc 'shorts' framing at second floor with new sister studs.
This was an interesting exercise, because the floor plan is so small that it was a waste of labor to fab shear wall panels to the minimum requirement, as opposed to just installing full sheets and calling it a day.
