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CWS Window Installation: The Kendall Owner’s Guide
CWS window installation in Kendall typically runs $340-$780 per opening depending on series, size, and whether the existing frame is preserved or replaced. We stock CWS-compatible hardware, fasteners, and sealant profiles on every truck, and most standard replacements are completed in a single visit. Homeowners usually discover a problem when they notice drafts around the sash, visible sealant separation after a heavy rain, or the window refusing to stay open on its own.
Sonia Raman and our crew have been setting CWS frames across Kendall for years, from the townhome blocks near Dadeland Mall to the single-family homes off Kendall Drive. The CWS product line is solid, but South Florida’s combination of salt air, afternoon thunderstorms, and UV exposure wears on installation components faster than the frame itself. We’ve learned to spot the difference between a failing part and a failing install.
Which CWS Models This Applies To
CWS manufactures several series common in Kendall homes built between 2015 and 2022: the CWS 3120 single-hung, the CWS 5400 double-hung, the CWS 7700 horizontal roller, and the CWS 8800 casement series. The installation hardware differs meaningfully between these lines. The 3120 and 5400 use a shared sill track profile, but the 7700 roller assembly requires a deeper pocket, and the 8800 casement hinge mounts on a reinforced jamb that cannot be retrofitted to a standard frame without modification.
To identify your series, check the etched marking in the glass corner or the label on the frame head. The model prefix tells us which installation kit to bring. For the 3120 and 5400, we carry both OEM CWS fasteners and a verified aftermarket equivalent from a Miami-based supplier that matches the 410 stainless spec. For the 7700 and 8800, we use OEM exclusively - the roller tolerance on the 7700 is too tight for aftermarket, and the 8800 hinge load rating is safety-critical.
One compatibility gotcha we’ve hit repeatedly in Kendall: the CWS 3120 installed in homes between 2016 and 2019 sometimes used a transitional sill adapter that CWS phased out. The current OEM part does not seat correctly without a shim kit we fabricate in-house. We check this on every 3120 call. Sightline Windows & Doors Kendall is an independent service provider, not affiliated with CWS.
Signs Your CWS Window Installation Is Failing

- Draft at the sash meeting rail even when locked. The compression seal has lost its memory, usually from UV breakdown of the EPDM rubber. In Kendall, we see this accelerate on west-facing elevations where afternoon sun hits hardest. The seal itself is replaceable, but if the sash is out of square, the new seal won’t seat.
- Water intrusion at the sill after heavy rain. The weep system is clogged or the sill pan flashing was never integrated with the house wrap. We find this often in Kendall’s older townhome stock where the original installer skipped the end dam sealant. The fix is removal, cleaning, and reinstallation with proper slope and sealant.
- Window will not stay open or slams shut unexpectedly. The balance system has failed. On CWS single-hung units, this is a coil spring assembly under constant tension. This is not a homeowner repair - the spring stores enough energy to cause serious injury if released improperly. We replace the balance cartridge with the sash removed and secured.
- Visible gap between frame and wall, or caulk pulling away. The installation fasteners have backed out or the frame has shifted. In South Florida’s sandy soils, subtle structural movement is common. We re-anchor with structural screws and backfill with backer rod and neutral-cure silicone rated for the joint width.
- Condensation between panes on insulated glass. The glass seal has failed, but the installation may be contributing if the frame is twisted or the glazing tape has degraded. We assess whether the IGU can be replaced in-frame or if the sash needs full removal.
Before
AfterReplacement Cost & What’s Included
| Service | Typical Range (Kendall) |
|---|---|
| Seal replacement, sash-in-place | $340-$480 |
| Balance system replacement (single-hung) | $420-$620 |
| Sill pan / weep system repair | $480-$780 |
| Full sash removal, reinstallation, and reseal | $580-$780 |
These prices include the part, labor, disposal, and our documented photo record. What drives the range: accessibility (second-story requires our pump jack or scaffold), whether the interior trim needs removal, and whether we discover hidden damage once the sash is out. We do not change the price after we start. Haven Clause 1 means the written quote from our measured survey is the final invoice. Every CWS installation repair carries our 365-Day Done Right Promise - if the seal fails or the balance goes within a year, we return and fix it at no charge.
DIY or Call Us?

There is one thing a Kendall homeowner can safely check: the weep holes at the exterior sill. If they’re clogged with debris or paint, clear them with a piece of wire and pour a cup of water to confirm drainage. Beyond that, CWS window installation work involves risks we do not recommend taking on.
The balance spring in a single-hung CWS unit is under enough tension to lacerate a hand or launch a sash across a room. We’ve seen homeowners attempt this with a screwdriver and end up in Kendall Regional’s ER. The structural screws that anchor a frame to the opening are specified by embedment depth and spacing; the wrong fastener or location compromises impact rating and voids the product warranty. And the silicone sealants we use require specific joint geometry and backer rod sizing - without it, the seal fails in the first rainy season.
We carry CWS-compatible parts on every truck, and our technicians are background-checked, uniformed, and identified by license number before arrival, per Haven Clause 3. Call (786) 321-3319 to schedule your free estimate.
FAQs
In South Florida’s climate, a properly installed seal or balance system typically lasts 8-12 years. The salt air and UV exposure near coastal Kendall shorten this compared to inland markets. We use UV-stable EPDM and neutral-cure silicones rated for 20-year exposure, but the reality of thermal cycling means 8-12 is the honest expectation. Call (786) 321-3319 for an exact quote - estimates are free.
The installation can almost always be repaired independently of the window itself. We replace failed components - seals, balances, fasteners, flashing - and preserve the CWS frame and sash. Full window replacement is only necessary if the frame is structurally compromised or the insulated glass seal has failed and the IGU is no longer available. Call (786) 321-3319 for an exact quote - estimates are free.
Most standard repairs are completed in 2-4 hours on-site. A balance replacement on a single-hung CWS 3120 takes about 90 minutes once the sash is secured. Sill pan work runs longer because we remove the sash, clean the opening, install new flashing, and let the sealant skin before reassembly. We schedule accordingly and arrive on schedule, per Haven Clause 2. Call (786) 321-3319 for an exact quote - estimates are free.
We stock CWS-compatible seals, balances, fasteners, and sealant profiles on every truck. The only items we occasionally need to order are specialty sill adapters for the transitional 2016-2019 3120 units and custom-width IGUs. If your repair requires a special order, we tell you before we start and schedule the return visit. Call (786) 321-3319 for an exact quote - estimates are free.
Sightline Windows & Doors Kendall also stocks parts and performs installation repair for PGT, CGI, and ES Windows product lines.
We also install and replace windows and doors across eight product categories - impact windows and doors, energy-efficient windows, sliding and patio doors, impact garage doors, and custom and geometric windows - drawing from eight verified manufacturer lines: PGT, CGI, CWS, ES Windows, ECO Window Systems, Mr-Glass, Therma-Tru, and ViewLux. Every engagement begins with a measured survey the customer keeps, and the written quote cannot differ from that document. All technicians are background-checked, uniformed, and identified by license number before arrival; every completed job is covered by the 365-Day Done Right Promise and leaves a documented photo record. Our founding principle since 2012: the measurement and the quote are the same document.
Ready to get your CWS window working right? Call (786) 321-3319 to schedule your free estimate. We’ll bring the measured survey, the written price, and the parts to fix it.
Written by Sonia Raman, Owner, Sightline Windows & Doors Kendall at Sightline Windows & Doors Kendall, serving Kendall and nearby areas.










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