Case Study 3-B: Dave Kowalski and the Sagging Floor

Dave Kowalski had been in his farmhouse for about seven months when he noticed the floor in the southeast corner of the living room was not level.

He'd placed a marble on the floor near the dining room table one afternoon — his niece had dropped it and he'd set it down while clearing the table — and watched it roll. It rolled toward the corner. Slowly but unmistakably, toward the southeast corner. Maybe six inches over four feet of roll.

Dave didn't panic. He measured. Using a long level on the floor, he confirmed: the southeast corner of the living room was approximately 3/8 inch lower than the rest of the floor. Over a span of about 10 feet, that was a slope of roughly 3/8 inch per 10 feet — detectable but not alarming. He photographed it, recorded the date in his maintenance log, and went to the crawlspace.

What Dave Found in the Crawlspace

The living room floor was in the southeast quadrant of the house. In the crawlspace below, Dave oriented himself and moved to the corresponding area.

The floor joists in this area were the original 2x10 dimensional lumber, spaced 16 inches on center, spanning from the exterior south foundation wall to the main center glulam beam, a span of approximately 13 feet 6 inches. At the time of original construction (1971), this was within the allowable span range for 2x10 lumber, though on the longer side.

Dave probed the joists with his awl in the systematic way he'd learned. Most were solid. But in the southeast quadrant, two adjacent joists showed something different: both had significant notches cut into their bottom edges, approximately midway along their span. The notches were not hairline damage — they were deliberately cut, clean-edged, approximately 2 inches deep and 3 inches long.

Nearby, looking at the plumbing in this area, Dave understood why: a drain pipe ran through this section of the floor, and whoever had installed it — decades ago, based on the pipe's age and the condition of the notches — had simply cut into the joists to accommodate the pipe's diameter. No sistering, no metal hangers, no code compliance.

He measured the notch depths: 1-7/8 inches deep and 1-3/4 inches deep, on two adjacent joists. The joists were 2x10 actual dimension (nominal 2x10, actual 1.5" x 9.25"). The code rule: notches are limited to 1/6 of the joist depth, which for a 9.25-inch joist means a maximum notch of about 1.54 inches — and they must be in the outer third of the span, not at mid-span.

These notches were: too deep (1-7/8 inches versus the 1.54-inch maximum), and in entirely the wrong location (at mid-span, which is the highest-stress location for a simply supported beam). The combination was a meaningful reduction in the structural capacity of both joists.

Dave was calm about this. He'd found a problem, not a crisis. The floor wasn't collapsing. The settlement had been slow and gradual — probably occurring over years or even decades as the over-stressed joists deflected slightly under load. He wasn't at risk of falling through the floor. But the situation needed professional evaluation and likely repair.

He photographed everything from multiple angles: wide shots establishing the location, close-ups showing the notch dimensions with a measuring tape in frame, and shots of the drain pipe that had prompted the original cutting.

The Framing Contractor's Assessment

Dave called a local framing contractor — a two-person operation whose principal, a man named Rob Hendricks, had been doing residential framing repair for 22 years. Rob came out the following week.

Rob went into the crawlspace, examined the joists, measured the notches, walked the floor above, and then came back up and sat at Dave's kitchen table to give his assessment.

"Two notched joists, both at mid-span, both over the code limit for depth," he said. "That's definitely the source of your deflection. The good news: the joists haven't failed. They've deflected — the floor slope you see is probably all the movement you're going to get, given that the load's been on there for decades without the joists going further. But they're running at reduced capacity and I wouldn't add load to this section of floor without fixing it."

His proposed repair: sistering each affected joist. Sistering means installing a new full-length joist alongside the existing one, connecting them with structural fasteners so they share the load. The sister joist provides the structural capacity that the notched joist has lost. The notched joists remain in place — they don't need to be removed, just supplemented.

For each joist, the process: cut a new 2x10 to length, work it into position alongside the existing joist (which requires some careful maneuvering in the crawlspace), fasten it with structural framing screws and structural adhesive at the top edge, and add metal connectors at the bearing points.

Rob's estimate: $750 for labor and materials for both joists (two sisters, approximately four hours of crawlspace work).

He also noted a secondary issue Dave hadn't focused on: the drain pipe that had caused the original notching was currently unsupported in the notch — just floating in the cut-out on each joist with no pipe hanger. "That pipe has been bouncing around in there for decades," Rob said. "I'd want the plumber to add proper pipe hangers when I'm done."

The Pre-Repair Decision: Jack It or Sister It?

Dave had read about a different approach before Rob's visit: hydraulic jacking. The idea: use a hydraulic jack in the crawlspace to gradually lift the sagging section of floor back to level, then prop it at level while the sisters are installed. This could, in theory, restore some of the original floor height and reduce the visible slope.

He asked Rob about it. Rob's answer was careful: "You can try to recover some level, but I'd do it very slowly — no more than 1/8 inch per day, and only if you understand that you might crack the drywall and trim above while you do it. These houses have usually adjusted to the settled position over time — the drywall, the trim, the doors. Lifting it back disrupts all that."

Dave thought about this. The slope was 3/8 inch over 10 feet. It was detectable if you looked for it, but he'd lived there seven months without noticing it until a marble rolled. He'd accepted the house as it was — this wasn't a recently developed problem, it was an old one. Slowly jacking the floor back up would fix the slope but might cause cosmetic damage he'd then need to repair.

His decision: sister the joists at their current position without jacking. Restore structural adequacy; live with the 3/8-inch slope as a known, stable, documented characteristic of the house. If it ever worsened, he'd address it then.

This is a legitimate and rational choice. Structural repair is not always about returning to perfect. Sometimes it's about stabilizing a non-ideal but tolerable situation.

The Repair: Sistering in a Tight Crawlspace

Rob and his assistant, Sal, arrived on a Saturday morning. Dave asked to watch from the crawlspace hatch — Rob was amenable.

The work was not glamorous. It was two men in a 36-inch-high space, maneuvering 14-foot 2x10 boards through a 20-inch-wide access hatch (which required an angle and some patience), positioning them against the joists with the help of temporary props, and fastening them with 3-inch structural screws at 12-inch intervals plus construction adhesive along the top edge where the subfloor contact occurred.

The new sisters were Douglas Fir No. 1 — better than the original No. 2 framing. Rob explained his choice: "For repair work, I always go up a grade. It's maybe $15 more per board and you get better structural properties with less variability."

Four hours after they started, both sister joists were in place and fastened. Rob walked the floor above while Dave watched from below — the floor felt noticeably stiffer under Rob's walking, even to Dave's untrained ear. The bounce that Dave hadn't consciously noticed until Rob pointed it out was gone.

The plumber came the following week and added proper pipe hangers to the drain pipe at 4-foot intervals, centering it in its path without contact with the joists.

Leveling the Floor Surface (Optional, Decided Against)

After the structural repair, Dave had the option of adding self-leveling underlayment — a pourable compound that flows to level and creates a flat surface before finish flooring goes down — to flatten the 3/8-inch slope in the living room. This would allow hardwood or tile to be installed with no visible slope.

He didn't do it. The living room had original hardwood flooring in good condition, and he didn't want to lift it, pour underlayment, and reinstall it. The slope was tolerable, stable, and documented. He added it to his home profile notes and moved on.

The cost of self-leveling underlayment for a 200-square-foot area with 3/8-inch maximum correction: approximately $400 in materials, plus a day of labor if done professionally. A future homeowner who wants to address the cosmetic issue can do so. For Dave's purposes, the structural issue was resolved.

Final Accounting and Lessons

Dave added these to his maintenance records, photographed the finished sisters in the crawlspace, and updated his home's structural profile.

The lessons from this case study are worth naming directly:

Regular crawlspace inspections catch things like this. Dave noticed the floor slope because he was paying attention. The notched joists had been there since some plumber had cut them decades ago. Without an annual inspection, Dave might have noticed the floor slope in year ten instead of year one — and during the intervening years, the joists would have continued to carry load at reduced capacity, potentially getting worse.

Understanding the problem enables good decisions. Because Dave understood what joist sistering was, what hydraulic jacking entails, and what the trade-offs were, he could make an informed decision about jacking versus not. He wasn't at the mercy of whatever Rob recommended — he could evaluate the recommendation against his own knowledge and values.

Not every structural repair requires returning to perfect. A stable, known, tolerable imperfection that has been professionally addressed is better than an unstable, unknown problem. Dave's floor will never be perfectly level, but it is now structurally sound and its condition is documented.

Rural ownership amplifies the value of DIY knowledge. If Dave hadn't gone into the crawlspace, checked the framing, and described the problem accurately to Rob, Rob might have spent two hours just figuring out the problem instead of walking in already informed. DIY knowledge isn't just about doing things yourself — it's about being an informed client when professionals are doing the work.