Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
CWS Roofing: The Sunnyvale Owner’s Guide
CWS-compatible roofing parts in Sunnyvale typically run $400-$1,800 installed for repairs and $8,000-$20,000 for full replacement, depending on whether we’re matching individual components or the full system. We stock common CWS fasteners, membrane sections, and flashing profiles on our trucks, and most CWS part replacements in Sunnyvale are completed in a single visit. Most owners discover a CWS roofing failure after a rain event, when water appears at the ceiling edge near a valley or penetration, or when they spot lifted shingles along the Santa Clara Valley’s typical south-facing exposures where thermal cycling is hardest on the adhesive strips.
Which CWS Models This Applies To
CWS Roofing Systems, a regional manufacturer based in Northern California, produces several residential lines that have been installed across Sunnyvale since the early 2000s. The most common we encounter are the CWS Presidential Shake (a laminated architectural shingle), the CWS Marathon 25 (three-tab strip shingle), and the CWS Northgate SBS-modified line, which uses a rubberized asphalt formula better suited to the temperature swings between Sunnyvale’s 45°F winter lows and 85°F summer peaks.
To identify your CWS model, check the shingle back for a printed code, usually found near the tar line, or look for a specification label on the original building permit if your home was built or re-roofed after 2005. The Presidential Shake runs 39 3/8 inches by 13 3/4 inches per shingle with a 5 5/8-inch exposure; the Marathon 25 is slightly smaller at 36 by 12 inches. Mixing these exposures during repair creates a visible wave pattern and voids any wind warranty, so measurement matters before we pull anything from stock. We carry both OEM CWS bundles and Atlas and CertainTeed equivalents where color match allows, and we’ll show you the physical sample against your existing roof before ordering.
Signs Your CWS Roofing Is Failing

- Curled or cupped shingle edges, especially on south and west faces. Sunnyvale’s 250-plus annual days of sun exposure dry out the asphalt binder in CWS three-tab shingles faster than the manufacturer’s 20- or 25-year rating assumes. Once the edges curl, wind uplift tears the shingle within one or two storm seasons.
- Granule loss visible in gutters or at downspout outlets. Those ceramic granules shield the asphalt mat from UV. Heavy loss, often appearing as sand-colored sediment after rain, means the shingle core is exposed and aging exponentially. On CWS Presidential Shake, granule loss often starts at the laminate bond line where manufacturing voids concentrate stress.
- Flashing separation at chimneys, vents, or wall abutments. CWS systems rely on step flashing integrated with the shingle course. In Sunnyvale’s clay-heavy soils, subtle foundation settlement cracks the mastic seal between metal and shingle, opening a path for water that travels laterally before dripping.
- Dark streaks or moss on north-facing slopes. Not merely cosmetic in our climate; moss roots lift shingle tabs and hold moisture against the mat. CWS shingles with early-generation algae resistance (pre-2010) are particularly susceptible in Sunnyvale’s shaded Heritage District lots.
- Sagging or soft spots when walked. Indicates degraded underlayment or, in CWS systems installed over skip sheathing common in 1960s Sunnyvale tract homes, localized rot where ventilation failed. This is structural, not surface, and requires deck inspection before any shingle work proceeds.
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AfterReplacement Cost & What’s Included
| Scope | Typical Range in Sunnyvale | What’s Included |
|---|---|---|
| CWS shingle repair (localized, up to 10 sq. ft.) | $400-$900 | Matching shingles, underlayment patch, fasteners, disposal |
| CWS valley or flashing repair | $600-$1,400 | Metal replacement, ice/water shield, mastic, integration with existing courses |
| Partial CWS re-roof (one slope or section) | $3,500-$7,500 | Tear-off to deck, new underlayment, shingles, vents, permits |
| Full CWS roof replacement | $8,000-$20,000 | Complete tear-off, deck repair as needed, full system, permits, final inspection |
What drives the range: deck condition (we find soft plywood in about 30% of Sunnyvale re-roofs over original construction), access complexity (steep pitches above 6:12 require tie-off systems), and whether we’re matching discontinued CWS colors or transitioning to a current line. Under Clause 1 of the Haven Standard, you receive a written line-item quote before any work starts - material counts, labor hours, permit fees, and disposal listed separately. Our 365-Day Done Right Promise covers the installation; shingle material warranty runs per CWS or equivalent manufacturer terms, which we document on your final invoice.
DIY or Call Us?

There’s a safe middle ground for CWS owners. You can walk the perimeter with binoculars, check gutters for granules, and photograph any lifted tabs or flashing gaps from the ground or a secured ladder. What you should not do: climb onto a slope steeper than 4:12 without fall protection, attempt to lift and re-seal curled shingles in cool weather when the asphalt won’t flex, or replace valley flashing without removing the surrounding shingle courses. The last requires cutting nails beneath three overlapping courses, a technique that looks straightforward on video but tears waterproofing layers when done by feel.
CWS shingle adhesive strips reactivate with solar heat, so a “simple” tab repair in January often becomes a five-shingle replacement by March when the brittle mat cracks. If you’re seeing active leaks, the damage is already deeper than the visible shingle. Call (650) 405-3637 and we’ll scope it with a written estimate, no charge.
FAQs
Expect 18-22 years from CWS three-tab lines and 22-28 years from Presidential Shake or SBS-modified products, assuming proper attic ventilation. Sunnyvale’s intense UV and occasional Santa Ana wind events accelerate aging on poorly ventilated roofs. Call (650) 405-3637 for an exact assessment - estimates are free.
Yes, if the failure is isolated to flashing, a few wind-damaged shingles, or a single valley, and the underlying deck is sound. We do not recommend patching when more than 25% of the field shows curling, granule loss, or brittle cracking - the labor to integrate new with failing exceeds the value. Call (650) 405-3637 for an exact quote - estimates are free.
Most single-component repairs, such as a vent boot or a 3-by-5-foot shingle patch, take two to four hours. A full CWS roof replacement runs three to five days in Sunnyvale, including permit pull, tear-off, deck repair, dry-in, shingle installation, and final inspection. Call (650) 405-3637 to schedule - estimates are free.
We stock common CWS-compatible fasteners, standard flashings, and underlayment on every truck. Specific CWS shingle colors and the full Presidential Shake palette are warehoused in San Jose and available next-day if not on hand. We confirm stock before scheduling so your crew isn’t waiting on material. Call (650) 405-3637 to verify availability for your color - estimates are free.
Rowan Construction Group Sunnyvale is an independent service provider and is not affiliated with CWS Roofing Systems. We also stock and install parts for KraftMaid, Cambria, and Silestone products across our trades.
Written by Grant Rowan, Owner, Rowan Construction Group Sunnyvale at Rowan Construction Group Sunnyvale, serving Sunnyvale and nearby areas.







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