Tamko Home Additions & ADU Nationwide

Tamko Home Additions & ADU: The San Diego Owner’s Guide

Tamko roofing products are commonly specified for home additions and ADU roof assemblies in San Diego, where the coastal climate and Title 24 energy codes create specific compatibility requirements. We stock and install Tamko-compatible ridge vents, underlayment, and shingle systems for addition tie-ins and standalone ADU roofs, with installed project pricing in San Diego running from $53,100 to $153,400 for full home additions and $106,200 to $259,600 for detached ADU construction. Most homeowners discover a Tamko component issue during the dry months when thermal expansion reveals gaps at the addition-to-existing wall junction, or when a permit inspector flags inadequate fire-rated assembly at the roof deck.

Call (858) 434-8926

Which Tamko Models This Applies To

Tamko’s residential roofing lines relevant to San Diego additions and ADUs break into three categories: Heritage series laminated asphalt shingles (the volume product we see specified), Titan XT impact-resistant shingles (required in some wildland-urban interface zones east of Interstate 15), and MetalWorks steel shingles (used where the architect wants standing-seam appearance without the standing-seam price). The critical identification point is the underlayment pairing: Tamko’s TW Metal and Tile Underlayment or TW Pro Synthetic must be matched to the shingle line for warranty validity, and the roll label will show the ASTM D226 or D4869 compliance mark that San Diego’s building inspectors look for.

We do not source through Tamko directly; we are an independent contractor with accounts at three San Diego roofing distributors who stock OEM Tamko products alongside quality equivalents like CertainTeed DiamondDeck and Owens Corning DeckDefense. For addition tie-ins where the existing roof has five years or more of UV exposure, we typically recommend staying OEM to avoid color-lot mismatch at the valley. On new ADU roofs, the aftermarket synthetics perform equivalently and cost 15 to 20 percent less per square, which we reflect in the written quote.

Signs Your Tamko Home Additions & ADU Is Failing

• Lifted ridge shingles at the addition junction. San Diego’s Santa Ana wind events expose inadequate nail patterns or missing hip and ridge cap adhesive. The underlying cause is usually an installer who ran the field shingle too close to the peak without the required 5-inch offset, leaving the ridge cap with insufficient fastening surface.
• Water staining on the existing home’s ceiling directly below the new tie-in wall. This points to failed step flashing where the addition roof meets the existing structure. Tamko’s installation guidelines specify 4-by-4-inch minimum step flashings; we regularly find 3-by-3-inch pieces substituted by crews rushing to beat weather.
• Granule accumulation in gutters after the first hot spell. Normal for the first month, but persistent shedding indicates thermal shock damage from a dark shingle color installed without adequate attic ventilation. Tamko’s Heritage in Rustic Black on a south-facing ADU in Clairemont or Linda Vista is particularly susceptible if the soffit vents were omitted.
• Soft spots at the eave when walked for gutter cleaning. This is delamination of the underlayment from the sheathing, usually from moisture driven inward by our marine layer and trapped by impermeable synthetic underlayment installed without the required top lap sealant.
• Permit correction notice citing inadequate Class A fire rating. San Diego County requires Class A assembly for all new construction including ADUs; Tamko Heritage with the proper underlayment meets this, but the inspector needs the ICC-ES report number visible on-site, which we include in our permit packet.

Before

After

Replacement Cost & What’s Included

Home addition and ADU roofing in San Diego falls within our broader addition pricing structure. A partial roof repair or tie-in reflash on an existing addition typically runs $4,700 to $21,250 depending on square footage and sheathing condition. Full addition roof replacement sits at $9,440 to $23,600 for standard asphalt shingle, while a complete detached ADU roof on a 500-square-foot structure with Tamko Heritage, synthetic underlayment, code-mandated drip edge, and proper ventilation runs toward the middle of that range.

Every written quote from Rowan Construction Group San Diego itemizes: tear-off and disposal per ton, sheathing replacement at $3.80 to $5.40 per square foot if needed, Tamko or equivalent material by the square with the specific product name and color lot number, labor by the man-hour with crew size noted, permit fees to the City of San Diego or relevant jurisdiction, and a 365-Day Done Right Promise covering both materials and installation. Under Clause 1 of the Haven Standard, this price is fixed; no change order is generated unless you request a scope change and sign the revision.

DIY or Call Us?

There is no safe DIY path for roof work on a home addition or ADU. The fall hazard is obvious, but the less visible risk is the structural one: an addition roof ties into load-bearing walls that were not designed for the point loads of a person plus materials. We have seen homeowners in San Diego’s older neighborhoods, particularly around North Park and South Park where original 1920s framing is common, punch through lath-and-plaster ceilings while attempting to sister rafters from above.

What you can safely check from the ground or a secured ladder: binocular inspection for lifted shingles, gutter granule load, and daylight visible through soffit vents (which should be clear, not painted over). What requires a trained eye: step flashing integration, underlayment lap sequencing, and the structural adequacy of the tie-in header. We offer free written estimates, and our documented photo record shows you exactly what we found without pressure to proceed. Call (858) 434-8926 to schedule.

FAQs