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Therma-Tru Roofing: The San Francisco Owner’s Guide
Therma-Tru roofing components aren’t actually a product line the company manufactures under its own name for roofs. Therma-Tru is a door manufacturer, and when San Francisco homeowners ask us about “Therma-Tru roofing,” they’re almost always referring to Therma-Tru’s weatherstripping, sill pans, thresholds, and door-bottom seals that sit at the base of exterior doors and allow water to migrate toward roofing edges, flashing, and drainage planes. If you’ve got a failed seal at the door-to-roof transition on a San Francisco flat roof or low-slope section, we carry the Therma-Tru replacement parts that fit, and typical installed repair costs in San Francisco run $470 – $2,125 depending on flashing scope. Owner Graham Stein’s crews handle these transitions weekly in neighborhoods like the Sunset, Noe Valley, and Bernal Heights, where fog moisture and wind-driven rain test door-to-roof seals harder than most other climates in the state.
Which Therma-Tru Models This Applies To
Therma-Tru produces multiple door series: Classic-Craft, Fiber-Classic, Smooth-Star, and Pulse. The roofing-adjacent components we’re talking about, the door bottoms, threshold caps, and sill pans, are not universal across all four lines. A Classic-Craft door with a 1-3/4″ thick slab takes a different sweep than a Smooth-Star with a 1-3/8″ slab, and the threshold profile differs again on Pulse models with their composite rails. The compatibility gotcha most San Francisco owners hit: Therma-Tru changed its sweep profile in 2018, so a pre-2018 door often needs the older T-863 sweep, while post-2018 units use the T-864 profile. If you can’t see a label on the hinge edge (or it’s painted over), pull the existing sweep and measure the kerf width, which will be 5/16″, 3/8″, or 7/16″. We stock all three widths on the truck, and we also stock the aftermarket equivalents from M-D Building Products and Frost King where the OEM part is on backorder. Therma-Tru’s own sill pans are an area where we always recommend OEM: aftermarket pans rarely match the drain-channel geometry on Therma-Tru frames, and in a city where a roof leak at the door means water inside the wall within a season, the spec matters.
Styles & brands we work with
Signs Your Therma-Tru Roofing Is Failing
- Water staining at the interior door base or adjacent ceiling edge. This means the door-to-roof flashing or sill pan isn’t shedding water away from the opening anymore, usually because the pan’s soldered corners have separated or the membrane under the pan has dried out after years of San Francisco fog cycling.
- The door sweep drags or shows daylight underneath. A compressed sweep lets wind-driven rain blow under the door and pool at the threshold, which then wicks into the subfloor and rots the rim joist where it meets the roof deck.
- Rust-colored drip lines on the exterior wall below the door. The threshold cap or its end caps have failed, and water is running down the face of the sheathing instead of out through the weep holes in the pan.
- Spongy or cupped flooring just inside the exterior door. By the time the floor moves, the leak has been active for months. The door pan, the membrane, or the counterflashing at the roof edge is no longer lapped correctly.
- Visible gaps between the door frame and the roof membrane or flashing. On flat and low-slope San Francisco roofs, the membrane should lap up the door curb a minimum of 6 inches; if it has pulled away or cracked at the lap seam, the seal is gone.
Replacement Cost & What’s Included
Door-to-roof transition repairs in San Francisco typically run $470 – $2,125 installed. The low end covers a door sweep, threshold cap, and re-caulking with a polyurethane sealant rated for the city’s wet winters. The high end covers a full sill pan replacement with new soldered copper or stainless pan corners, membrane lap repair at the roof edge, and new counterflashing, which is more common on older Richmond and Sunset homes where original pans date to the 1940s and 50s. Every price Graham writes includes the parts, the labor, the drop cloths inside, and a photo of the clean-up before the crew leaves. If the work is a roof replacement at the door’s roof section, that falls under roof replacement pricing, $9,440 – $23,600 in San Francisco, and the door flashing is included as part of the roofing scope. We don’t issue a number and then grow it when the pan comes out and we find rot. Written price first, every time, and the 365-Day Done Right Promise says if it’s not right, we make it right.
See the difference
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AfterDIY or Call Us?
Replacing a Therma-Tru sweep or threshold cap is a table-level job you can knock out on a Saturday morning if the kerf width is visible and the screws come out clean. Where we say step back: anything involving the sill pan, the roof membrane lap, or exposed flashing at the roof-to-door junction is best handled by someone who has pulled a pan on a San Francisco flat roof and knows what the rot profile under a 60-year-old threshold actually looks like. The danger is not electrocution or fall risk here; it’s making the leak worse while feeling like you fixed it. A pan that isn’t sloped, a membrane lap that isn’t cleaned and primed, a flashing seam sealed with the wrong product, and you’ve moved water inside the wall instead of away from it. If you want us to look at it, call (831) 480-4497 and Graham or someone from the crew will walk it with you.
FAQs
Door sweeps last 5 – 8 years in San Francisco before the vinyl compression set makes them drag or gap; sill pans typically last 30 – 50 years in this climate, though salt air near the ocean or a roof deck that traps moisture against the pan can cut that to 15 – 20 years. Call (831) 480-4497 and we’ll tell you what you’re actually looking at.
The pan can almost always be replaced without touching the door itself, which means the door, frame, and interior trim stay in place while the pan, membrane, and flashing get redone from the exterior. Only if the door’s bottom rail has rotted from years of sitting in water would the door need to come out. Call (831) 480-4497 for an exact answer after we look at it.
A sweep and threshold replacement is a one-visit job done in under two hours; a full pan and flashing replacement on a San Francisco flat roof is usually a one-day job with a second half-day for membrane patch cure and water testing.
We stock the common Therma-Tru sweeps, threshold caps, and end caps on the truck in all three kerf widths, plus the OEM sill pan kits for the most-installed Therma-Tru models in San Francisco. We also carry compatible hardware and parts for KraftMaid cabinetry, Cambria surfaces, and Silestone finishes when a door repair wanders into adjacent work. Call (831) 480-4497 and we’ll confirm stock before we schedule the visit.
Talk to Graham About Your Therma-Tru Door-to-Roof Leak
If water is coming in at the door, or the sweep has given up, or the roof membrane at the door looks tired, call (831) 480-4497 and ask for a walkthrough. Graham’s team has worked throughout San Francisco for years, from Outer Sunset cottages to full-floor remodels within walking distance of Dolores Park, and the first thing you’ll get is a written price before any tool touches the floor. Tell me what the room needs to do, and we’ll figure out the rest from there.
Written by Graham Stein, Owner, Elmstead Remodeling San Francisco at Elmstead Remodeling San Francisco, serving San Francisco and nearby areas.
