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Therma-Tru Custom & Geometric Windows in Miami Lakes: What to Know First
As an independent Therma-Tru service provider in Miami Lakes, we measure, fabricate, and install custom and geometric Therma-Tru windows for homeowners whose openings don’t accept standard rectangles. Most Therma-Tru custom jobs in Miami Lakes run 4 to 6 weeks from measured survey to installation, with the written price fixed at the survey stage under Haven Clause 1. We do not quote from photos; we read the rough opening on site, document it, and that document becomes the scope.
This page is for Miami Lakes homeowners who already own Therma-Tru products and need arched, curved, trapezoid, or oversized geometric replacements, or who are specifying Therma-Tru for a new custom opening. Call (786) 755-8730 to schedule a measured survey. The price we write is the price you pay.
How Therma-Tru Products Fail - and How We Fix Them
- Classic-Craft canvas separation in arched tops. The arched transom units in the Classic-Craft line use a canvas substrate between the fiberglass skin and the frame. In Miami Lakes, where the afternoon sun hits west-facing arches at 95-plus degrees for months, that canvas delaminates and bubbles. We see this on Main Street historic renovations where the arch is decorative but the seal is structural. We remove the sash, strip to substrate, and rebuild with OEM-compatible fiberglass lamination rated for South Florida UV exposure.
- Smooth-Star geometric corner stress cracks. Smooth-Star’s fiberglass formulation is lighter than Classic-Craft, which is an advantage until you cut it into a trapezoid or pentagon. The corner miters in geometric configurations carry load differently than rectangular units, and we’ve found stress fractures initiating at the interior corner radius after 3 to 5 years. Our fix: we specify reinforced corner blocks on every custom Smooth-Star geometric, fabricated from the same lot number as the sash to maintain thermal expansion match.
- Impact-rated custom units with seal failure at the glazing bed. Therma-Tru’s impact-rated custom windows use a dual-seal system, but the geometric cuts interrupt the continuous seal path. In Miami Lakes, where the building department enforces HVHZ (High Velocity Hurricane Zone) standards, a failed seal means a failed inspection. We re-bed with Sika or Dow 795 in a continuous bead, tool the joint to a concave profile, and pressure-test before we leave. Sonia Raman checks the operating hardware personally; she does not leave until someone else has opened and closed the unit.
- Oversized Direct Set units with frame deflection. Direct Set geometric windows over 48 inches on a side rely on the frame for structural support, but Therma-Tru’s standard jamb depth doesn’t always accommodate Miami Lakes block construction without shimming. We’ve measured openings where the previous installer shimmed with composite wedges that compressed under load, dropping the sash and binding the lock. We fabricate custom jamb extensions from cellular PVC, match the sightline to the original, and secure with Tapcons into the lintel, not the shim stack.
- Decorative glass delamination in curved units. Therma-Tru’s decorative glass options, Granada and Homeward, use a resin interlayer that yellows faster in curved configurations because the bend creates micro-stress in the laminate. Miami Lakes humidity accelerates the reaction. We source replacement curved insulated glass units (IGUs) from the same OEM vendor Therma-Tru uses, but we specify a Trosifol or SentryGlas interlayer with higher moisture resistance. The warranty remains intact because we do not alter the frame or the glazing stop profile.
Our Therma-Tru Custom & Geometric Windows Process

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Measured survey on site. We arrive with a laser measure, a level, and a camera. We document the rough opening in six dimensions, note the wall construction (Miami Lakes block, frame, or combination), and record the existing sightline. You keep a copy of the survey; it is Haven Clause 1 evidence.
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Diagnostics and failure mode identification. We test operation, check seal continuity with a smoke pencil, and inspect the glazing bed for delamination or moisture intrusion. If the unit is impact-rated, we verify the HVHZ label is intact and legible.
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Parts decision: OEM or verified aftermarket. For Classic-Craft and Smooth-Star, we prefer OEM sashes and frames when the lead time is under 5 weeks. For discontinued profiles or urgent timelines, we source from a verified aftermarket fabricator whose extrusions we’ve tested for thermal expansion compatibility. We document the source on the written scope.
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Fabrication and arrival inspection. Custom geometric units ship from Therma-Tru’s plant or our verified fabricator. We inspect at our warehouse for corner integrity, glass clarity, and label accuracy before scheduling installation.
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Installation, seal, and operation test. We set the unit plumb and square, seal with specified sealant, and test operation. Haven Clause 4 requires evidence: we photograph the installation, the sealant profile, and the label. Then someone other than the installer operates the hardware before we consider the job complete.
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Documentation delivery and 365-Day Done Right Promise activation. You receive the photo record, the written scope, and the warranty document. If anything is not done right, we make it right. That is written into the Haven Standard, not offered as a courtesy.
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AfterWhat Therma-Tru Custom & Geometric Windows Costs in Miami Lakes
These are the price ranges we have written for Therma-Tru custom and geometric work in Miami Lakes over the past 24 months. Every job is measured before we name a number; these are ranges, not quotes.
| Scenario | Typical Range |
|---|---|
| Standard geometric replacement (trapezoid, triangle, single arch) | $1,800 - $3,400 per opening |
| Double-arch or compound curve (Classic-Craft or Smooth-Star) | $3,200 - $5,600 per opening |
| Oversized Direct Set geometric (over 48 inches, impact-rated) | $4,500 - $7,800 per opening |
| Decorative glass upgrade (Granada, Homeward, or custom IGU) | $800 - $1,600 additional per unit |
| Jamb extension or frame rebuild for block construction | $400 - $900 additional per opening |
What moves the price: wall condition (block vs. frame), impact rating requirement, decorative glass, and whether the opening requires structural reinforcement. We do not discover these conditions after we write the price; we discover them during the measured survey, and the price is written after. Call (786) 755-8730 to schedule your free measured survey and written estimate.
Why Miami Lakes Homeowners Call Sightline Windows & Doors Miami Lakes for Therma-Tru Work

We are not a Therma-Tru dealer. We are an independent installer who specifies Therma-Tru when the opening calls for it, which means we also specify PGT, CGI, CWS, and ES Windows when they fit better. That independence matters in Miami Lakes, where a Main Street historic facade may need impact-rated glass in a profile that looks like 1958, and only one manufacturer makes it.
The Haven Standard governs every job: written price before work starts, verified crew with license number on record, documented photo evidence, and no surprises. Our change-order rate is low because Sonia Raman reads the rough opening before she quotes it, not after. Her standing rule: measure it right the first time or budget for the second trip. The 365-Day Done Right Promise is stamped on every job, not offered as a promotion. Calls are answered by a live person, 24/7, at (786) 755-8730.
FAQs
No, provided the installation follows Therma-Tru’s published guidelines and uses OEM or compatible components. The warranty covers manufacturing defects, not installation errors, which is why we document every step to the Haven Standard. If a defect appears, we help you file the claim with the documentation we collected. Call (786) 755-8730 if you have a specific concern about your existing warranty status.
Standard custom geometries from Therma-Tru run 4 to 6 weeks from order to delivery. Complex curves or oversized impact-rated units can extend to 8 weeks. We do not quote installation dates until the unit is in our warehouse and inspected, because promising a date on an unconfirmed shipment is how schedules break. Call (786) 755-8730 to check current lead times for your specific profile.
Sometimes. We maintain relationships with aftermarket fabricators who can replicate discontinued Therma-Tru profiles from extrusion samples. We need to measure the existing unit and, in some cases, remove a corner of trim to access the frame profile. If replication is not feasible, we will tell you during the survey and propose a replacement that preserves the sightline. The measured survey is free; call (786) 755-8730 to schedule.
Repair makes sense when the frame is sound and the failure is isolated to glass, seal, or hardware. Replacement makes sense when the frame has delamination, the corner structure is compromised, or the unit is pre-2010 and parts are unavailable. We do not recommend replacement for margin; we recommend it when the repair would exceed 60 percent of replacement cost or when the repair cannot restore impact rating. We document both options in writing. Call (786) 755-8730 for a free second opinion on any estimate.
Yes, for any replacement that alters the opening size, changes the egress configuration, or involves impact-rated glass in the HVHZ. Miami Lakes building department requires permits for impact-rated installations and inspects for label compliance and fastening schedule. We pull the permit, schedule the inspection, and correct any deficiency at our cost under the 365-Day Done Right Promise. The permit cost is included in the written price, not added later. Call (786) 755-8730 to confirm whether your specific job requires permitting.
Written by Sonia Raman, Owner, Sightline Windows & Doors Miami Lakes at Sightline Windows & Doors Miami Lakes, serving Miami Lakes and nearby areas.










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