Refrhus · Basement · measured 2026-08-18

Basement post geometry

Plan-view details for the six basement posts, drawn in isolation because their relationships to the joists and girders are too fine to read in the Sweet Home 3D plan.

Source lives in the house repo at hoards/refrhus/basement-post-details.html; the published page is generated from it. Every dimension is either measured in the basement or derived under a stated assumption. The datum is the south interior cinder face at model y = 511.0 — the one line the basement shares with a Main-floor exterior wall.

Post — what you place

Member above

3.5″ steel pole

How the paneling thickness fell out

Three west-zone tape runs that overlap rather than abut — and that overlap is what makes them solvable.

Each tape run crosses the post it starts from, so the segments overlap by one casing depth apiece; subtracting those chains them to 269.3125″ panel-to-panel. The north paneling is measured directly at 1.75″ — round three's cinder reading and round two's panel reading land on the same bathroom wall, that far apart. The south figure is what remains after the utility zone's 272.25″ shell, and is the last assumed number in the set.

Two chains that meet

The bathroom chain validates itself. Round two walked from the north paneling through the door frame and bar to the bathroom's inner south wall, landing at 76.125″. Round three walked from bare cinder inside the drain-stack void to the same wall, landing at 77.875″. The 1.75″ difference is the paneling, and it means twelve hand measurements across two sessions agree to the sixteenth.

North and south chains meet within a quarter inch. Working south from the cinder through the den puts the NW post's north face 86.0625″ off the north block. The girder relationship — 0.375″ proud at NW, ≈2.5″ to each post's south face, 3.125″ thick — then predicts the N post's north face at 85.125″. Round three's independent chain, running the other direction entirely, measures 84.875″. Nothing in that comparison assumes the shell is rectangular, so the two halves of the basement genuinely register against each other.

The four wood-encased posts

Plan view, north up. Each is a 3.5″ steel pole inside a site-built 1x6 casing; the casing is the obstruction, so the casing is what the model carries.

SW post

straddles joist-06

x 371.90 · y 416.25 — the pole lands almost exactly under joist-06's east face.

NW post

clear east of joist-06

x 375.59 · y 327.41 — the girder's north face sits 0.375″ proud of the post. Two independent chains agree within 0.06″.

S post

flush with joist-12 beam

x 458.25 · y 414.19 — positioned from the north datum via the N post, not from the middle-south reading.

N post

casing rotated 90°

x 460.78 · y 326.72 — deeper than wide because its long planks run north–south where the other three run east–west. Confirmed by eye, so the dimensions stand as measured.

The east pair

Bare poles, no casing — and the lap in joist-19 is what made their east–west positions solvable.

Two 1.5″ segments lapping with a ⅛″ gap put their centrelines 1.625″ apart. The NE plate registers to the north segment and the SE pole to the south one, which is why the two poles sit 1.38″ apart in x rather than collinear. They carry different beams, so there is no reason they should line up.

Values as built into the model

South cinder face at y = 511.0″. Casing dimensions for the western four; a Cylinder at 3.5″ for the eastern two.

Post	x (in)	y (in)	W × D (in)	x (cm)	y (cm)	W × D (cm)
SW	371.90	416.25	6.0625 × 5.375	944.63	1057.28	15.40 × 13.65
NW	375.59	327.41	6.1875 × 5.1875	953.99	831.62	15.72 × 13.18
S	458.25	414.19	6.25 × 5.625	1163.96	1052.04	15.88 × 14.29
N	460.78	326.72	5.1875 × 6.1875	1170.38	829.87	13.18 × 15.72
NE	559.76	325.00	3.5 round	1421.79	825.50	8.89 round
SE	561.13	396.00	3.5 round	1425.27	1005.84	8.89 round

Residual uncertainty

The south paneling is the one assumed number. No bare block is exposed on the den's south wall, so 1.1875″ is what remains after the utility zone's shell rather than a measurement. Assuming it instead matches the north's measured 1.75″ implies a west-zone shell of 272.8125″ against the utility zone's 272.25″ — 0.56″ apart, below the ±1″ of joist drift already carried on the NW and N posts.

Joist drift. The grid was read 5–7 ft off the south wall. SW sits near that band; NW and N are 15 ft away, where the recorded ½″-per-few-feet drift could move their east–west reference by up to an inch.
The bar counter does not fit the tape chain. The counter was seen overhanging the bathroom's west wall by about 3″, but the placement here makes the wall the more westerly. Likeliest reconciliation is a countertop overhanging its own base. Nothing structural depends on it.