Foundation As-Built

Before I dive into the foundation in Chief Architect, I thought I would study the as-built foundation as it is visible around the perimeter and in the basement. Credit to Peggy for suggesting taking elevation points around the house; advice I largely ignored because I have a survey.

The garage is at 260' 0" and the main house is at 263' 0". That may not be precisely accurate, but we can start there. The basement floor may not be 256' 0", but it is a convenient number.

Level	Terrain	House
Basement	256.0	-48”
Top of footing (SW corner)	257.14583	-34¼”
Garage, BR3	260.0	0”
Top of Garage curb	260.16667	2”
Breezeway floor	262.95833	35½”
Main House Fin. Floor	263.0	36”
Garage Plate	269.375	112½”
Main Plate	270.75	120¾”

 Main House

On the main house, we measure to the last lap siding board, the course that has vents between the 2x8 floor joists. It is maybe 1/4" below the mud sill. As I understand the floor construction, that means the F. F. to bottom of siding is 10 1/2", meaning that the bottom of the siding is at 25 1/2" (262.125).

The ground across the N wall is level at 20" (261.66667). The Porch is 35 1/2", the step is 28 1/2" (or 28" closer to the kitchen), and the front walk is 25" where it hits the step.

The ground at the E wall is level at 23" (261.91667). The NE corner is difficult to measure because of the brick veneer, but the ground slopes up a few inches as it turns the corner.

The ground along the S wall is 3 1/2" (260.29167) in the middle, sloping up to 22" (261.83334) at the SE corner.

The W wall of the main house in back, the concrete patio hits the house at 1 1/2" (260.125). At the kitchen in front, it is 20" (262.6667).

The bottom of the mud sill is 25 3/4" (262.14583)

Basement

The ground inside the N wall slopes from 1 3/4" (260.14583) at the NE to -8 1/4" (259.3125) at the NW. The sewer line punches through the N wall with an invert of about 9 1/2" (260.79167).

The ground inside the E wall slopes from 1 3/4" (260.14583) at the NE to -14 1/4" (258.8125) at the SE.

The ground inside the S wall is level at -14 1/4" (258.8125) to the half wall. The basement floor is -48" (256.0), sloping to the door and the catch basin beyond.

The floor is the same at the W wall until the half wall. There the ground slopes from -28 1/4" (257.64583) at the half wall to -8 1/4" (259.3125) at the NW corner.

The top of the half wall is at -16" (258.6667), or 32" up from the floor. The top of the 6x8 girders is 27 1/4" (262.27083), which is the top of the mud sill and bottom of the 2x8 joists.

Footings are exposed at the SW area where the basement slab is. The top of these footings is -33 1/2" (257.20834). The footing on the W wall protrudes 12" into the room (and seems to align with the outside of the stem wall), making it 18" wide. The footing on the S wall protrudes only 6 1/2", but likewise aligns with the outside of the stem wall.

Sloping formwork (on W wall). Note exposed footing on N wall (right).

It appears that the footings on all but the S side (and maybe there, too) were not poured level. The formwork seems to slope, as well, suggesting that they only leveled the top of the stem wall. 

A more traditional 6" x 12" footing under the N and E walls seems to be partially exposed on the inside, making the top of the footing about 3" above the adjacent grade.

Breezeway

The Breezeway floor is 35 1/2" (262.95833). The ground on the north side is 24" (262.0). The ground on the south side is -8 1/2" (259.29167).

Garage + BR3

The floor is a 4" slab with top at 0" (260.0) and bottom at -4" (259.66667). There is a 2" curb all around. Top of curb is 2" (260.16667). The bottom of the siding is 1 3/4" (260.14583).

The driveway across the N wall is 0" (260.0).

The E wall in front slopes up to about 32" (262.6667) at the breezeway. At the back it is roughly level at -8" (259.33334) along the E wall of BA3.

The ground at the S wall is generally -23 1/4" (258.0625), but it is -12" (259.0) at the SE corner and slopes off to -31 1/4" (257.39583) at the SW corner.

The ground along the W wall slopes linearly from -12" (259.0) at the NW corner to -31 1/4" (257.39583) at the SW corner.