Therma-Tru Home Additions & ADU Nationwide

Therma-Tru Home Additions & ADU: The Fort Lauderdale Owner’s Guide

Therma-Tru entry systems installed in Fort Lauderdale home additions and ADUs typically run $45,000-$130,000 for the full addition, with door and sidelight packages ranging $2,800-$7,500 installed. We stock Therma-Tru-compatible jamb extensions, sill pans, and impact-rated sidelight kits on our Fort Lauderdale trucks, and most replacements are completed in a single visit. Most owners discover the problem when water beads on the interior jamb after a summer storm, or when the door sticks in the frame during our humid months.

Call (754) 254-7676

Which Therma-Tru Models This Applies To

Therma-Tru categorizes their residential entry systems by door slab material: Classic-Craft (fiberglass with wood-edge construction), Fiber-Classic (smooth or textured fiberglass), and Smooth-Star (paint-ready fiberglass). For Fort Lauderdale additions and ADUs, we see Classic-Craft and Fiber-Classic most often because both carry Miami-Dade HVHZ impact ratings when paired with Therma-Tru’s own sidelight and transom systems.

To identify your exact system, check the hinge-side jamb for a stamped date code and series mark, usually 12-18 inches above the floor. The critical compatibility gotcha in our market: Therma-Tru impact-rated sidelights use a 2-inch jamb depth, while their standard line uses 1-3/8 inch. If your addition was built post-2017 to current Florida Building Code, you almost certainly have the deeper jamb. We also see mismatched retrofits where a previous owner installed a standard Therma-Tru slab in an impact-rated frame, which fails inspection and leaks under pressure.

OEM Therma-Tru parts ship from Maumee, Ohio with a 7-10 day lead time. We stock Fortlee and Endura aftermarket equivalents that match Therma-Tru’s sill pan geometry and meet Florida Product Approval, cutting wait time to same-day. Rowan Construction Group Fort Lauderdale is an independent service provider, not affiliated with Therma-Tru.

Signs Your Therma-Tru Home Additions & ADU Is Failing

• Water staining at the base of the jamb. The sill pan weep holes are clogged with Fort Lauderdale’s fine coral sand, or the Endura sill cap seal has compressed after 6-8 years of thermal cycling. Water that should drain to the exterior pools behind the pan and wicks upward.
• Door binds in the upper corner opposite the hinges. The hinge jamb has pulled away from the framing, usually because the original installer used standard fasteners instead of the longer structural screws Therma-Tru specifies for impact-rated jambs. Our humidity accelerates the loosening.
• Daylight visible around the weatherstrip. The Q-Lon or magnetic weatherstrip has lost compression set. In south Florida, UV exposure through screen doors degrades the bulb faster than the manufacturer rates for, often in 4-5 years rather than the stated 10.
• Sidelight glass fogs between panes. The insulated glass unit seal has failed. Therma-Tru’s sidelight IGUs use a dual-seal system, but our salt air and afternoon thunderstorm temperature swings stress the edge seal harder than inland climates.
• Threshold flexes or cracks when stepped on. The composite threshold substrate has absorbed moisture through a compromised end cap. This is common in ADUs where the threshold sits close to grade and splashback from our heavy rains hits repeatedly.

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Replacement Cost & What’s Included

What drives the range: slab size and glass option (clear vs. decorative), whether the existing frame is square (older Fort Lauderdale additions often aren’t), and how much exterior trim we need to match. Under Clause 1 of The Haven Standard, you get a written line-item quote before we touch a tool. No change proceeds without a signed change order. The 365-Day Done Right Promise covers the installation and the parts we supply.

DIY or Call Us?

There’s one thing you can safely check: the weep holes at the exterior sill. Clear them with a piece of wire or compressed air. If water drains freely, you’ve solved a maintenance issue, not a parts failure.

Everything else on a Therma-Tru impact-rated system is where DIY goes wrong. The sill pan must integrate with the water-resistive barrier behind the exterior cladding. The jamb must be shimmed to stay plumb while the door hangs open during fastening. And the Florida Product Approval sticker must remain legible for resale and insurance purposes. We’ve replaced three owner-installed units in Victoria Park alone this past year, all because the threshold wasn’t bedded in sealant and the subfloor rotted.

We carry the common Therma-Tru jamb depths, sill pans, and weatherstrip profiles on our Fort Lauderdale trucks. Call (754) 254-7676 and we’ll confirm your series from a photo, quote the repair in writing, and schedule the work.

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