Free in-home measure and quote - PGT, CGI and CWS impact lines compared on your actual openings, style by style
Therma-Tru Impact Windows & Doors in Three Lakes: What to Know First
We install and service Therma-Tru impact windows and doors in Three Lakes as an independent provider - not a factory-authorized dealer - with written prices delivered before any work begins and a 365-Day Done Right Promise on every job. Most Therma-Tru impact unit consultations in Three Lakes are scheduled within 48 hours, and your measured survey becomes your written quote; the two documents do not diverge. Call (786) 808-5792 to schedule a free estimate or bring us a competitor’s written quote for a free second opinion.
This page is for Three Lakes homeowners who already have Therma-Tru products and need impact-rated replacement, repair, or an honest assessment of whether the unit can be saved. We also specify PGT, CGI, CWS, and ES Windows when the opening calls for a different performance tier or price point.
How Therma-Tru Products Fail - and How We Fix Them
- Impact sash corner separation on Vented Sidelight units. The thermal break adhesive in early Vented Sidelight production cycles degrades faster in South Florida’s UV load, and the sash corners begin to gap at the miter. We see this on homes west of SW 120th Avenue where afternoon exposure is harshest. We disassemble the sash, remove the failed thermal break, and re-bond with a two-part structural adhesive rated for the expansion coefficient - not caulk, not screws.
- Laminated glass delamination in Classic-Craft impact doors. The PVB interlayer in Classic-Craft impact-lite configurations can fog at the perimeter when the glazing tape loses compression set, typically after 6-8 years in Three Lakes humidity. The fix is not a new door; it is reglazing with fresh setting blocks, proper edge clearance, and a replacement laminated lite that meets the original design pressure. We document the old lite’s etch code before removal to match the interlayer thickness exactly.
- Multi-point lock misalignment on Fiber-Classic French doors. Therma-Tru’s adjustable multi-point hardware drifts as the composite stile takes on seasonal moisture. In Three Lakes, the wet season swells the frame enough to throw off the deadbolt throw by 1/8 inch or more. We do not shim the strike; we reset the keepers using the factory adjustment slots, then verify engagement with a torque gauge. If the composite has permanently deformed, we replace the active stile with an OEM part.
- Weep system blockage in Syntegra sliding impact doors. Syntegra’s bottom rail weep chambers clog with pollen and roof grit during Three Lakes’ spring bloom, trapping water in the track. Homeowners mistake this for a seal failure. We pull the sash, flush the weep chambers with low-pressure water, and rod the drain holes. If the sill pan is pitched backward from original installation, we correct the pitch - no new door required.
- Impact-rated astragal wear on Double Door sets. The T-astragal bulb seal on Therma-Tru double doors compresses permanently after repeated cycling, and the metal astragal itself fatigues at the screw holes. In impact-rated units, this is a pressure-boundary failure, not just a draft. We replace with OEM astragal assemblies or, when Therma-Tru lead times stretch past 4 weeks, we fabricate a compatible replacement from 6063-T6 extrusion with a Santoprene bulb that matches the original compression set.
Our Therma-Tru Impact Windows & Doors Process

- 1
Measured survey. Sonia Raman or a Verified Crew technician arrives in uniform with license number visible, records rough opening dimensions to 1/16 inch, notes frame plumb and square readings, and photographs existing conditions. You keep the survey.
- 2
Diagnostics with etch code verification. We read the tempered or laminated lite etch code to confirm the original design pressure and interlayer specification. For Therma-Tru units, we cross-reference the etch against the Miami-Dade Notice of Acceptance database to confirm the product is still listed - some pre-2017 NOAs have been superseded.
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Parts decision: OEM or verified equivalent. We quote OEM Therma-Tru components first. If lead time exceeds your tolerance or the part is discontinued, we specify an aftermarket equivalent with matching DP rating and submit the substitution in writing for your approval - no surprises.
- 4
Installation per Haven Standard. Verified Crews work to the written scope only. Fastener pattern, sealant bead, and shimming are photographed at each stage. The measured survey and final invoice are the same document - Haven Clause 1.
- 5
Operational test and documentation. We cycle the unit 10 times, verify lock engagement with feeler gauges, and run a smoke pencil on the perimeter. You receive the photo record, the written warranty, and the 365-Day Done Right Promise stamp.
- 6
Cleanup and final walk. We leave the opening cleaner than found. No debris, no caulk smears, no hardware packaging. The invoice is due only when the documentation packet is in your hand.
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AfterWhat Therma-Tru Impact Windows & Doors Costs in Three Lakes
| Scenario | Typical Range |
|---|---|
| Therma-Tru impact single-hung reglazing (laminated lite, standard size) | $680 - $1,150 |
| Classic-Craft impact door reglazing with new laminated lite | $1,400 - $2,200 |
| Fiber-Classic multi-point lock reset or replacement | $320 - $580 |
| Syntegra sliding door weep system repair and sill pan correction | $450 - $780 |
| Full Therma-Tru impact window replacement (standard opening, installed) | $1,850 - $3,400 |
| Double door T-astragal replacement with impact-rated assembly | $890 - $1,450 |
Price movers: lite size and design pressure rating; whether the original NOA is still active; accessibility (second-story openings require staging); and whether the frame is salvageable or requires full rough-opening remediation. We do not quote until we measure - and once we measure, the price is fixed. Call (786) 808-5792 for your written estimate.
Why Three Lakes Homeowners Call Sightline Windows & Doors Three Lakes for Therma-Tru Work

We have installed and serviced 18,000+ openings since 2012, and a measurable share of those have been Therma-Tru units in South Florida subdivisions where the builder spec’d them for cost and the homeowner now needs them to perform under actual hurricane conditions. Sonia Raman reads a rough opening once, quotes it straight, and installs it right - nothing else belongs on the invoice.
Our multi-brand capability matters: if your Therma-Tru unit is discontinued or the lead time does not match your timeline, we can specify PGT, CGI, CWS, or ES Windows from our verified lines without starting over with a new contractor. Every technician is background-checked, uniformed, and identified by license number before arrival - Haven Clause 3. Calls are answered by a live person, 24/7. And the 365-Day Done Right Promise is not a verbal assurance; it is stamped on your paperwork under the Haven Standard.
FAQs
Therma-Tru’s warranty covers original defects in material and workmanship; it does not cover field modifications, improper installation, or damage from impact events. As an independent Therma-Tru service provider, we document every part source and procedure so you have a clear record if a warranty claim arises. We use OEM parts where possible and note any substitution in writing. Call (786) 808-5792 if you need help interpreting your warranty documents.
Most reglazing jobs are completed in one working day once parts arrive. Therma-Tru OEM laminated lites typically ship within 2-3 weeks; if your timeline is shorter, we can often source a DP-matched equivalent from our verified aftermarket suppliers with your written approval. We do not start work until the price is agreed and the parts are in hand.
Replace when the frame is rotted, the composite stile has permanently deformed, or the unit no longer carries a valid Miami-Dade NOA for your wind-borne debris zone. Repair when the failure is isolated to glass, hardware, or seal - most Therma-Tru composite frames outlast their first glazing cycle by a decade or more. We make this recommendation in writing, with photos, after the measured survey.
Yes, within current production availability. We photograph your existing panel profile, glass pattern, and hardware finish, then cross-reference against Therma-Tru’s active catalog. If the original style is discontinued, we provide three written alternatives at different price points. We also stock ViewLux and ECO Window Systems entry door lines when the opening specification allows a different manufacturer.
Yes, for any replacement that alters the rough opening or changes the egress configuration. Miami-Dade County requires a permit and final inspection for impact-rated window and door replacements to confirm the new unit meets the Florida Building Code and the Notice of Acceptance is current. We pull the permit, schedule the inspection, and pass it - included in the written scope, never added later. Call (786) 808-5792 to confirm whether your specific job requires permitting.
Written by Sonia Raman, Owner, Sightline Windows & Doors Three Lakes at Sightline Windows & Doors Three Lakes, serving Three Lakes and nearby areas.










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