Tamko Home Additions & ADU Nationwide

Tamko Home Additions & ADU: The Sunnyvale Owner’s Guide

Tamko roofing products used in Sunnyvale home additions and ADU construction typically run $45,000-$130,000 installed, depending on whether you’re extending an existing roofline or building a standalone unit. We stock Tamko Heritage series shingles and compatible underlayment, and most ADU roof sections can be spec’d and started within two weeks of a signed contract. Most Sunnyvale owners discover their Tamko roofing system needs attention when the addition’s ceiling shows water staining after our first heavy winter rains, or when a permit inspector flags inadequate headlap on a homeowner-permitted ADU roof.

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Which Tamko Models This Applies To

Tamko’s Heritage series, Heritage Vintage, and Heritage IR (impact-resistant) are the shingles we see most often on Sunnyvale additions and ADUs built between 2015 and 2023. The Heritage line carries a 30-year limited warranty with a 10-year full start period; the Vintage and IR lines step up to 50-year coverage. To identify what you’re working with, check the cellophane strip on the shingle back for the printed series name, or look for the Tamko lot number on the wrapper of any leftover bundles in the garage.

Here’s where compatibility gets specific: Tamko Heritage shingles require a minimum 4/12 roof pitch, which matters on low-slope ADU designs common in the Lakewood Village area where owners max out height limits. Below 4/12, you’ll need Tamko’s approved low-slope membrane system, not standard shingles. We source OEM Tamko for color-matched repairs and use Atlas or Malarkey equivalents when the original color is discontinued, which happened with several Heritage Vintage lots after the 2019 formulation change. The aftermarket shingles match ASTM D3462 spec but always verify the granule color in Sunnyvale’s particular afternoon light before committing to a large section.

Signs Your Tamko Home Additions & ADU Is Failing

• Granule loss exposing the asphalt mat. Tamko shingles shed granules faster on south-facing ADU roofs in Sunnyvale’s intense summer sun. Once the mat shows, UV degradation accelerates and leaks follow within one to two rainy seasons.
• Curling or clawing at shingle edges. This indicates the fiberglass core has separated from the asphalt, often from inadequate attic ventilation in a converted garage ADU where soffit vents were never installed. The shingle is structurally compromised and will lift in wind.
• Water stains on the addition ceiling after rain. The leak may be ten feet uphill from the stain due to Sunnyvale’s shallow-pitch additions. We trace it with a hose test, but the underlying cause is usually failed step flashing where the addition meets the original structure.
• Shingles brittle enough to crack when walked on. Tamko’s asphalt formulation stiffens faster in dry Santa Clara Valley heat than in coastal climates. If a shingle cracks under a repairman’s foot, the whole field is near end of life.
• Visible fiberglass fibers at shingle edges. This means the weathering asphalt has worn through entirely. On ADUs built during the 2018-2020 rush, we’re seeing this at year six or seven instead of the expected twelve to fifteen.

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Replacement Cost & What’s Included

The range depends on three factors: whether we’re matching existing roof planes or building new, how many layers need tear-off (Sunnyvale limits most structures to two), and whether the addition’s structure can handle the weight of upgraded shingles like Heritage IR. Our quote lists material costs per square, labor hours at a fixed rate, and subcontractor scope separately, so you see where each dollar goes before signing. Under Clause 1 of the Haven Standard, that written price is locked; no change proceeds without a signed change order. The 365-Day Done Right Promise covers workmanship, and Tamko’s own warranty runs 30 to 50 years depending on series.

DIY or Call Us?

A homeowner can safely check for granule loss in gutters or photograph ceiling stains for documentation. You can also verify your Tamko series from leftover bundles or building permits pulled with the city of Sunnyvale.

What you should not do: walk a pitched roof to inspect, remove shingles to check nail patterns, or attempt a partial re-roof on the addition-to-house junction. That junction is the leak point on nine out of ten failing additions we see, and it requires proper step flashing integration with the existing roof, which means working on both surfaces simultaneously. Falls from single-story ADU roofs cause more residential construction injuries in Santa Clara County than any other accident type. We’re background-checked, uniformed, and carry the documented photo record equipment as standard; call (650) 405-3637 and we’ll scope it properly.

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