Free in-home measure and quote - PGT, CGI and CWS impact lines compared on your actual openings, style by style
Therma-Tru Window Replacement: The Florida City Owner’s Guide
We stock and install Therma-Tru-compatible window replacements in Florida City, with typical installed pricing from $340 to $780 per opening depending on frame depth, glass package, and whether the original was impact-rated. Most Therma-Tru units we encounter in Florida City homes were installed between 2015 and 2020, and we carry the common sash, frame, and hardware configurations on our trucks. Most Florida City homeowners discover the problem when the sash won’t stay open, they feel air movement at the meeting rail, or condensation appears between the glass panes after a storm season.
Which Therma-Tru Models This Applies To
Therma-Tru window systems span several series, and the part you need depends on which generation is in your wall. The Classic-Craft and Fiber-Classic lines used in Florida City subdivisions built after 2017 typically carry a 3¼-inch frame depth with integrated nail fins, while earlier Benchmark and Traditions series often sit at 2⅞ inches with clip-on fins. The difference matters: the wrong replacement binds in the opening or leaves a gap at the head jamb.
Check the spacer bar between the glass panes for an etched AAMA certification number, or the hinge-side jamb for a stamped manufacturing date and series code. If the label is painted over, measure the frame depth from interior to exterior at the sill, and the visible glass dimensions to the nearest ⅛ inch. We match against Therma-Tru’s published spec sheets, not guesswork.
We are not affiliated with Therma-Tru; we are an independent service provider. For most Florida City replacements, we use OEM Therma-Tru sash packs and frame components where the series is still supported. Where Therma-Tru has discontinued a profile, we source aftermarket equivalents tested to the same DP rating and U-factor, documented in writing before you sign. The decision is yours, and we note the origin of every part on your quote.
Signs Your Therma-Tru Window Replacement Is Failing

- Sash drops or won’t stay open. The coil balance or block-and-tackle system has lost tension. In Florida City’s humidity, the balance shoes crack after 6-10 years, and the sash weight overcomes the weakened spring. We see this most often in west-facing units where afternoon heat accelerates plastic fatigue.
- Visible moisture or fog between glass panes. The insulating glass unit (IGU) seal has failed. Once argon or air escapes, Florida City’s high dew points guarantee condensation. The glass pack needs replacement; cleaning between panes is not possible without destroying the IGU.
- Air infiltration at the meeting rail or sill. The weatherstrip has compressed or the interlock is out of square. Therma-Tru’s compression seals degrade faster where salt air is present, and Florida City’s proximity to Biscayne Bay and Homestead Bayfront Park accelerates this.
- Frame corner separation or sill rot. The composite or vinyl frame has pulled at the fusion-welded corners, or the sill weep channels are clogged and holding water. We document this with photos; corner keys can sometimes be re-welded, but sill replacement usually means full frame removal.
- Hardware operates roughly or locks don’t engage. The multipoint lock mechanism has corroded, or the keepers have shifted as the frame settled. Therma-Tru’s earlier multipoint systems used zinc alloy components that oxidize in coastal air; we replace with stainless or coated equivalents where available.
Before
AfterReplacement Cost & What’s Included
| Component | Price Range (Installed) |
|---|---|
| IGU (glass pack only, sash retained) | $340 - $520 |
| Sash pack (glass + new sash frame) | $480 - $680 |
| Full frame replacement, standard size | $620 - $780 |
| Full frame replacement, impact-rated | $740 - $1,100 |
| Balance system repair (both sides) | $180 - $260 |
What drives the range: frame depth, whether the original was impact-rated (requires laminated glass and reinforced hardware), and the condition of the existing rough opening. Rotten sill plates or out-of-square framing add material and labor we identify during our measured survey. Your written quote itemizes each line; the number on that document matches the final invoice. Haven Clause 1: Have it in writing. The 365-Day Done Right Promise covers the installation and components. We pull permits where Florida City or Miami-Dade County requires them, and inspections are included in the scope.
DIY or Call Us?

There is nothing wrong with checking what you have. Verify the series label, photograph any etched numbers, and test whether the sash operates smoothly without forcing it. What you find, we use.
Where DIY goes wrong: removing a sash with a failed balance risks the coil spring releasing uncontrolled force. The glass pack in a Therma-Tru IGU weighs 40-80 pounds depending on size and impact rating; a dropped unit is a laceration hazard and a total loss. Out-of-square frames, hidden rot, and the Florida Building Code’s wind-load requirements for replacement openings mean that even a “simple” swap often reveals conditions the original installation concealed. We have replaced units in Florida City where a homeowner’s self-measure was ¼ inch short, and the gap at the head jamb voided the manufacturer’s warranty.
Call (786) 418-6182 to schedule your free measured survey. We bring the spec sheets, the parts inventory, and the photo documentation. You keep the written quote before any work starts.
FAQs
In Florida City’s climate, a properly installed Therma-Tru vinyl or composite window typically performs 15-22 years before major component failure, though coastal exposure and west-facing orientation can shorten IGU seal life to 8-12 years. Salt air at elevations below 15 feet, common in neighborhoods near Homestead Bayfront Park, accelerates hardware corrosion. Call (786) 418-6182 for an exact quote on your specific unit - estimates are free.
No. A failed IGU seal cannot be resealed to manufacturer specifications in the field; the glass pack must be replaced. We have seen “defogging” services advertised in South Florida, but injected solvents do not restore argon fill or structural seal integrity, and they void any remaining warranty. Call (786) 418-6182 for an exact quote - estimates are free.
A standard sash pack or IGU replacement in an existing Therma-Tru frame takes 2-3 hours per opening, including removal, installation, insulation, and trim. Full frame replacements require 4-6 hours and may need a second visit for interior trim completion. We schedule arrival times, not windows - Haven Clause 2: Arrive on schedule. Call (786) 418-6182 to book.
We carry the most common Therma-Tru sash configurations, balance systems, and hardware for Florida City service calls, including the 3¼-inch frame profiles used in post-2017 construction. Less common or discontinued series may require a 3-5 business day order. We verify stock against your measurements before scheduling. Call (786) 418-6182 to confirm availability for your model.
Measure it right the first time. The wall does not accept revisions. Sonia Raman and our crew have served Florida City properties long enough to know that salt air, storm exposure, and the Florida Building Code’s wind-load requirements make product selection a decision worth documenting before anyone touches a tool. Every job leaves a photo record, every quote is written before work starts, and every technician is background-checked, uniformed, and identified by license number before arrival - Haven Clause 3: Verified Crews.
Written by Sonia Raman, Owner, Sightline Windows & Doors Florida City at Sightline Windows & Doors Florida City, serving Florida City and nearby areas.










Before
After
Before
After
Before
After