A Mariemont Tudor that ran 18°F colder upstairs (and the foam package that fixed it)

The starting point

A 1928 Tudor revival in Mariemont. Original slate roof, 2,400 sqft, 4 bedrooms upstairs, full basement. Steam radiators (1950s replacement boiler upgraded twice since), no central air originally; window units in upstairs bedrooms. Owners had lived there 11 years and accepted the second-floor temperature delta as "old house quirks." When their oldest moved to the front bedroom, the temperature complaints started in earnest. December reading: 54°F upstairs while the thermostat downstairs read 72°F.

Sister house on the next street, identical year and footprint, runs about 6°F colder upstairs. So the 18°F delta was clearly not just "Tudor architecture." Something specific was wrong.

What the thermal imaging found

The partner-network installer brought a FLIR camera on the in-home estimate. Three problem areas lit up immediately:

1. Cathedral ceiling sections at the roof gables. Original 2x6 rafter cavities held degraded R-19 fiberglass and a layer of dust. Thermal imaging showed clear convective loops: cold air from the soffit was running up the rafter bays, behind the fiberglass, and exiting at the roof peak. Effective R-value: maybe R-3 to R-5. 2. Knee walls behind the upstairs bedroom closets. Vertical 2x4 framing, fiberglass batts that had slumped to the bottom 6 inches of the cavity, dead air space above. The bedroom-side surface of the knee wall measured 41°F at 25°F outdoor. Thermal short-circuit between the conditioned bedroom and the unconditioned attic dead-space behind. 3. Rim joist around the entire house perimeter. Original 1928 sill, no insulation. Visible cold bands across the basement ceiling on thermal imaging. Air leakage measured ~9 ACH50 on the blower-door test (typical leaky old house is 7-10 ACH50; tight new construction is 1-3 ACH50).

The combination meant the upstairs bedrooms were both losing heat through the roof and being chilled by air infiltration up from the basement via the wall cavity stack effect. Fixing one alone would not move the needle.

The fixed-price quote

The partner contractor wrote a $7,800 fixed quote covering:

1. Closed-cell spray foam to the underside of the roof deck in cathedral sections, 4 inches (R-28), creating a conditioned attic 2. Closed-cell spray foam on knee-wall backsides, 3 inches (R-21) 3. Closed-cell spray foam at the rim joist, 3 inches (R-21), continuous around the entire perimeter 4. Sealing of recessed light penetrations and the chimney chase from attic side 5. Pre and post blower-door tests 6. Manufacturer-stamped tax documentation packet for IRS Form 5695

Total foam volume: about 950 board feet at $1.85/bf average. Crew time: 3 days.

Install

Day one (roof deck and rim joist). Crew on site 7:30 AM. Truck-mounted Graco rig set up on the side driveway. Roof-deck spray completed by 1:00 PM in two lifts (2-inch passes to manage exotherm; cathedral cavities are tight). After lunch, basement rim joist around the whole perimeter, sealed at sill plate and along the band joist face. Day-end blower test reading: 6.2 ACH50 (down from 9.1).

Day two (knee walls and details). Crew handled the trickiest part: spraying the back side of bedroom knee walls without disturbing the closet drywall. Access through removable attic-access panels behind the closet headers. Sealed all chimney chase penetrations and recessed-light cans from the attic. Final spray pass on the cathedral cavities to bring R-value to spec.

Day three (cleanup, post-test, documentation). Foam fully cured. Final blower-door test: 3.8 ACH50, a 58% reduction from baseline. Manufacturer paperwork packet handed off, including spray-product data sheets for the closed-cell foam (Demilec Heatlok HFO Pro 2.0 used; HFO blowing agent for ozone-friendly profile).

Pre and post numbers

| Metric | Pre-foam | Post-foam | |---|---|---| | Upstairs winter low | 54°F | 67°F | | Downstairs/upstairs delta | 18°F | 5°F | | ACH50 (blower door) | 9.1 | 3.8 | | December gas bill (32°F avg) | $342 | $221 | | Estimated annual heat-fuel savings | n/a | $850-$1,100 | | 25C federal tax credit claimed | n/a | $1,200 (max for 2026) |

What this case shows

• Tudor cold-upstairs is rarely "just old houses." It is almost always a stack-effect problem (basement rim joist + attic plane both leaking) compounded by under-insulated knee walls. Fixing one without the other underwhelms.
• Thermal imaging during the estimate visit pays for itself. A 30-minute camera walkthrough by the partner-network installer reveals where the problem actually is, not where you guess it might be. That is what makes a fixed-price quote possible.
• Closed-cell at the rim joist is the universal Cincinnati move. Whether the home has cold upstairs, cold floors over crawl, or a winter draft at the front door, the rim joist is almost always involved. It is the single highest-ROI insulation project for any pre-2000 Cincinnati home.
• Tax credit math matters. The Section 25C credit knocked $1,200 off the homeowner's effective project cost. Combined with the $850-$1,100 annual fuel savings, payback is roughly 5.5-6.5 years.

What homeowners should do before getting a quote

Walk the house in mid-winter (sub-30°F outdoor). Touch interior walls, especially behind closets and under windows. Note temperature differences room to room. Check the basement rim-joist band for visible drafts (light a stick of incense and watch the smoke). Photograph the attic insulation depth at three or four points. Bring those notes to the in-home estimate; they cut estimating time and surface the right scope first.