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Tamko Home Additions & ADU: The Pasadena Owner’s Guide
Installed home additions in Pasadena run $45,000 to $130,000, and ADUs run $90,000 to $220,000 depending on size, site access, and how much of the existing structure we can reuse. Sawyer Remodel Pasadena handles the full Tamko-capable scope: footings, framing, roofing, weatherproofing, and tying the new build into your existing home so it doesn’t look like an afterthought. Most owners discover they’ve outgrown a room the same month a failed part forces the conversation: a leaking roof plane, a rotted ledger board, or an old window wall that’s no longer weather-tight.
We’re an independent Pasadena general contractor. We are not affiliated with Tamko directly, but their materials show up on a lot of Southern California additions and we’ve worked around them long enough to know what holds up and what doesn’t.
Which Tamko Models This Applies To
Tamko makes a range of building products that end up in home additions and ADU builds here in Pasadena: laminated and three-tab shingles, underlayment, waterproofing membranes, and flashing systems. The compatibility question is less about a “model number” and more about the product line, because different Tamko series have different installation specs. A Heritage Pro shingle, for example, carries different exposure and nail-line requirements than a Rustic Black Walnut or laminated Elite Glass-Seal line.
Before you replace anything, look at the edge of an existing shingle or the corner of a membrane roll. Tamko prints the series name and sometimes the line number right on the material. Take a photo before it ends up in a dumpster. That photo tells us whether we can match an existing roof plane on a Pasadena home addition, or whether we should re-roof the whole new build footprint. Aftermarket equivalents exist for some Tamko underlayments and flashing, but we’ve seen too many Southern California additions where a generic peel-and-stick underlayment fails after four or five summers of UV exposure. For roofs and waterproofing, OEM or a same-spec brand like GAF or CertainTeed is almost always the better call.
Styles & brands we work with
Signs Your Tamko Home Addition or ADU Is Failing
- Water staining at the ceiling-wall junction of the addition. In Pasadena, this usually means the Tamko flashing at the roof-to-wall tie-in has pulled loose, or the step flashing was never lapped correctly when the addition was built. Water finds the seam and rides it inside.
- Wavy or lifting shingle tabs on the new roof plane. Southern California heat cycles bake adhesive strips hard, and a Tamko shingle that wasn’t sealed properly in the first season will curl at the corners by year two or three.
- Efflorescence or damp concrete at the addition’s stem wall. That white chalk on the concrete usually means the Tamko or generic waterproofing membrane wasn’t run far enough up the pony wall, and groundwater is wicking through. Pasadena’s clay-heavy soils hold moisture against foundation walls for months after rain.
- Do you feel a draft at the old-to-new floor transition? A common failure on Pasadena additions is a sill plate that wasn’t sealed or anchored properly where the original house meets the new framing. You’ll feel it in December before you’ll see anything.
- Interior drywall cracks at the addition’s header or ceiling plane. This is usually movement: expansive soil, undersized headers, or a wall that was framed without enough crown on the beam. Once the cracks repeat in the same lines after patching, it’s structural, not cosmetic.
See the difference
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AfterReplacement Cost & What’s Included
For Pasadena specifically, a full home addition at $45,000 to $130,000 is the broad envelope. A garage conversion runs $30,000 to $80,000, and a detached ADU runs $90,000 to $220,000. The spread comes down to site conditions: a flat Pasadena lot with clear access and a single-story addition is the low end. A hillside lot, poor drainage, a second story, or failing existing framing pushes you toward the top end fast.
What’s included: our written price lands before any work starts and covers demolition, footings and foundation, framing, the Tamko or same-spec roof assembly, weather-resistive barrier, windows, doors, and finishing. The invoice you approve is the invoice you pay: no change orders without a written number, no surprise line items, no “we’ll figure it out later” pricing. Every addition and ADU we build carries our 365-Day Done Right Promise: if it isn’t done right, we make it right, in writing, for a full year after the job closes.
DIY or Call Us?
A homeowner can safely do a few things before calling. Walk the addition’s exterior after the first rain of the season. Look for shingle granules collecting at downspouts, loose flashing, or standing water against the stem wall. Take photos with your phone. Note where the water stains are inside. That helps us price the repair accurately over the phone.
What you shouldn’t do is climb a ladder onto the roof of your Pasadena addition to replace Tamko flashing or shingles yourself. It’s not the tile work that hurts people; it’s the fall from the eave onto a driveway or the patio below. Roof work on two-story additions, in particular, is for trained professionals with proper fall protection. The same goes for cutting into a load-bearing wall to “just add a door” between the original house and the addition. We’ve been called after both of those shortcuts went sideways. If you’re not sure whether a crack is cosmetic or structural, call (626) 657-5396 and send us a photo first. We’ll tell you honestly whether it’s a handyman-sized fix or a full crew.
FAQs
In Pasadena’s dry heat and intermittent heavy rain, a properly installed Tamko laminated shingle roof on an addition typically lasts 18 to 25 years. The failure points are usually flashing, not shingle wear. Call (626) 657-5396 if your addition’s roof is under 15 years old and already leaking; we’ll figure out what corner got cut.
Yes, if the damage is isolated to one roof plane, one section of flashing, or one stem wall. For additions in Pasadena, we repair what’s failing and leave what’s still performing. If the failure is widespread in the framing or the waterproofing was never installed right, a partial repair costs more in the long run than a full correct. We price both and show you the numbers before we touch anything.
A small single-story addition in Pasadena usually runs 10 to 16 weeks from first dig to final inspection. A detached ADU runs longer, often 5 to 8 months depending on plan check at the city and site work. We’ll give you a written schedule when we give you the written price, and we send photo updates before and after each phase.
We order Tamko or same-spec shingles, underlayment, and flashing for each specific Pasadena job, and we bring everything to the site on day one. We don’t store roofing materials in a warehouse where they bake in the heat, because that’s how you end up installing a shingle that’s already half-cured before it hits the deck. You’re only ever waiting on the city, not on us.
Call (626) 657-5396 to schedule a free estimate for your Tamko home addition or ADU work in Pasadena. Written price, live arrival time, and no surprises.
Written by Luca Romano, Owner & Lead Contractor, Sawyer Remodel Pasadena at Sawyer Remodel Pasadena, serving Pasadena and nearby areas.
