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Therma-Tru Home Additions & ADU: The Fort Worth Owner’s Guide
If you’re planning a home addition or ADU in Fort Worth and want Therma-Tru doors specified into the build, the installed project range runs $45,000 to $130,000 for a full addition, with ADU construction landing between $90,000 and $220,000 depending on square footage and site conditions. We stock and install Therma-Tru entry doors, patio doors, and sidelight systems as part of our addition and ADU builds, and we can source the matching parts if a door on an existing addition has failed. Most Fort Worth owners call us because an exterior door on an older addition won’t seal against Texas heat, or the sill has rotted out from the wet-dry cycle we get every spring, and the door no longer closes square.
Bradford Remodeling Co Fort Worth is an independent remodeling contractor. We are not affiliated with Therma-Tru, but we specify their doors regularly and know their parts ecosystem well enough to order what’s needed without guessing at the hardware aisle.
Which Therma-Tru Models This Applies To
Therma-Tru builds their exterior door systems on a few core platforms, and the parts situation changes depending on which one you have. The Classic-Craft and Fiber-Classic lines use a fiberglass skin over a polyurethane core, which we see most often on Fort Worth additions built in the last 15 to 20 years. The Smooth-Star line is the budget-friendly fiberglass option, and it shares hinge and weatherstripping geometry with the other residential lines but not always the same sill dimensions. The Pulse and Benchmark lines are designed for builder-grade installs, and those are the ones where a replacement threshold or sweep tends to get “close enough” ordered by someone who didn’t check the extrusion profile first.
Here’s the compatibility gotcha we run into regularly: Therma-Tru sills are not universal. A Classic-Craft sill from 2012 will not necessarily drop into a Smooth-Star frame from 2019, even if both doors measure 36 inches wide. The sill cap dovetails into the frame’s bottom rail differently between series. Before we order a part, we pull the original door’s serial label from the hinge edge or the hinge-side jamb. If that label is gone, we take three measurements: the door slab width and height in inches, the sill depth front-to-back, and the weatherstrip channel profile. That tells us if we’re ordering an OEM Therma-Tru part or a suitable aftermarket equivalent that will actually hold the seal.
For addition and ADU work specifically, we prefer OEM Therma-Tru parts on anything load-bearing to the door’s operation: hinges, sill caps, and multipoint lock bodies. For consumable weatherstripping and sweeps, a quality aftermarket equivalent from a supplier we’ve vetted works fine and saves money. Curtis Lane has spent enough years pulling permits and swinging hammers to know which corners you don’t cut.
Styles & brands we work with
Signs Your Therma-Tru Home Additions & ADU Is Failing
- Door doesn’t latch without lifting or shoving. The slab has settled out of square, usually because the sill on the addition side of the house has shifted with Fort Worth’s clay soil. If the hinge side of the frame is still true but the latch side has dropped, you’re usually looking at a sill or frame issue, not the slab itself.
- Drafts and light visible around the edges. The compression weatherstrip on older Therma-Tru doors loses its memory after years of Texas heat and cold fronts. The rubber hardens, the magnetic strip loses hold, and any 40-degree February morning shows exactly where the gaps are.
- Water staining on interior flooring near the door. This is the one we tell Fort Worth homeowners not to ignore. The sill’s drainage channels can clog with dirt and construction dust from the addition work itself, and once water stops draining outward, it works its way under the threshold and into the subfloor. By the time you see the stain, the OSB underneath is usually compromised.
- Sidelights fogging between the glass panes. Therma-Tru door glass is great until the seal fails. Fort Worth’s humidity and heat cycling eventually breaks the insulated glass seal, and once that happens, the only fix is a new glass unit or a full new door panel.
- Multipoint lock binds halfway through the throw. On Classic-Craft and Fiber-Classic doors with the three-point locking system, the hardware can bind if the frame has shifted even an eighth of an inch. Forcing the deadbolt through the binding point is how people snap lock rods and end up with a door that won’t unlock at all.
Replacement Cost & What’s Included
Here’s where the numbers land for Fort Worth. If a Therma-Tru door on your existing addition just needs parts (weatherstrip, sweep, threshold, hinge), you’re looking at a service call plus parts, not a remodel budget. If the door and frame have failed to the point where replacement makes sense within a larger project, the conversation shifts to the addition or ADU scope. That’s where the $45,000 to $130,000 range for home additions lives, and where ADUs run $90,000 to $220,000 depending on whether you’re doing a garage conversion or a new detached build.
For a standalone Therma-Tru door replacement as part of an addition repair, you’re typically in the $1,500 to $5,000 installed range depending on the model, glass package, and whether the rough opening needs reframing. We’re not going to hide labor in the parts number. You get a written breakdown before work starts, every time. That’s The Garrison Standard: a price in writing before a single tool comes out, no numbers that change at the door.
Every completed project from Bradford Remodeling carries the 365-Day Done Right Promise. If the door install or the addition work fails within that year, we come back and correct it at no charge. That’s not a handshake promise. It’s written into the scope you sign.
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AfterDIY or Call Us?
You can safely replace a door sweep or compression weatherstrip yourself if you buy the correct profile. That’s a 20-minute job with a utility knife and a screwdriver. You can also clean out the sill drainage channels with a wire brush and air hose. What you shouldn’t do is pull a Therma-Tru door slab off its hinges and try to re-hang it, or cut a new sill into an existing frame, especially on an addition door that’s already binding. Getting a 100-pound fiberglass slab back into square on a settled frame is not a weekend project. If the frame itself has moved, the fix lives in the framing, not the door.
If you’re in Fort Worth and the door on your addition or ADU won’t seal, latch, or drain properly, call (682) 204-4897. We’ll send a tech who reads the frame before quoting the fix. And you’ll get the number in writing before we touch anything.
FAQs
A properly installed Therma-Tru exterior door on a home addition in Fort Worth should last 20 to 30 years on the slab and frame, but the weatherstripping, sweeps, and threshold caps are consumable parts that typically need replacement every 3 to 7 years depending on sun exposure and how much the foundation has moved. Fort Worth’s clay soil expands and contracts with moisture, and that movement shortens the life of any door component that depends on a tight, square frame. If your door is less than 10 years old and already failing, the issue is usually the rough opening framing underneath it, not the Therma-Tru product itself.
Yes, in many cases the sill cap and threshold can be replaced without pulling the entire door assembly, as long as the frame bottom rail and the subfloor beneath are still sound. The sill cap is a sacrificial component designed to be swapped. The problem on some Fort Worth additions is that the original builder didn’t flash the rough opening correctly, and the sill cap replacement will fail again in a few years because the underlying water management was never right. That’s the first thing we check.
Most standard Therma-Tru door replacements on a Fort Worth home addition take one day once the door is on site, assuming the rough opening doesn’t need reframing. If we’re pulling out rot at the threshold or correcting a settled opening, add a second day for framing and trim work. Custom-order Therma-Tru doors with specific glass packages typically have a 2 to 4 week factory lead time, so we order early and confirm the spec twice before the order goes in.
Our techs carry common weatherstrip profiles, door sweeps, threshold caps, and hinge hardware for the Therma-Tru lines we install most in Fort Worth, plus the standard cartridge-style sill covers. Full door slabs and custom sidelight glass are special-order from our Therma-Tru supplier. But most service calls we run on additions and ADUs get resolved same-day with what’s on the truck. Call (682) 204-4897 and we’ll tell you what we can do before we show up.
Get a Written Price for Your Fort Worth Addition or ADU
If you’re pricing a home addition or ADU in Fort Worth, or you have a Therma-Tru door on an existing addition that’s failing, call (682) 204-4897. We’ll put a real number in front of you, in writing, with the scope itemized. Straight scope, firm price, no surprises at final walkthrough. That’s how Bradford Remodeling Co Fort Worth runs every job, and it’s how we’ve earned our place among Fort Worth’s remodeling contractors. We also work with KraftMaid, Cambria, and Silestone for kitchen and bath scopes, so the same written-price standard applies across your whole project.
Written by Curtis Lane, Owner, Bradford Remodeling Co Fort Worth at Bradford Remodeling Co Fort Worth, serving Fort Worth and nearby areas.
