Tamko Home Additions & ADU Nationwide

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

If you’re planning a home addition or ADU in Austin with Tamko roofing and waterproofing products, you’re looking at a real installed range of $45,000 to $130,000 for an addition, and $90,000 to $220,000 for a full ADU build. We source Tamko shingles, underlayment, and waterproofing components directly through our supplier network, and we’ll give you a written price before the first board goes up. Most homeowners reach out to us mid-project because they’ve hit a wall: their general contractor ghosted, the Tamko product they specified isn’t available through their current installer, or the waterproofing detail on a connection point between old roof and new addition has already started leaking after a hard Austin rain.

Call (325) 225-5429

Here’s the situation we see most often: a contractor prices the job with one Tamko shingle line, then swaps in a cheaper line at installation. The homeowner doesn’t notice until the roof is already on. The difference matters in our climate. Austin’s July heat pushes roof surface temperatures past 150 degrees, and our spring storms dump inches in a few hours. The right Tamko product spec, installed with the right underlayment, is the difference between a 12-year roof and one you’re patching after the first hailstorm. We don’t do that bait-and-switch. The written number we give you covers the exact Tamko product we install.

Key takeaways:

• Installed home additions in Austin run $45,000 – $130,000; full ADUs run $90,000 – $220,000.
• We spec Tamko products by model line, not just “Tamko” as a generic brand.
• We write the price down before work starts and back it with our 365-Day Done Right Promise.
• Trevor Nash runs the jobs in Austin; you’ll get a live person on the phone at (325) 225-5429 when you call.

Signs Your Tamko Home Additions & ADU Is Failing

• Granule loss in the gutters or at downspouts. If you’re finding black or gray grit accumulating after rains, the shingle surface is breaking down. In Austin, UV exposure accelerates this. When the granules go, the asphalt underneath begins to cook and crack.
• Water staining on the ceiling inside the addition or at the transition wall. This is the classic “old roof meets new roof” failure. The flashing detail where your addition connects to the original house is the most common leak point we fix, and it’s almost always because someone skipped the correct Tamko valley metal or installed the water shield in the wrong sequence.
• Curling shingle edges or lifting tabs after a wind event. High wind from a spring storm front will lift shingles that weren’t installed at the right temperature or with proper nail placement. A lifted tab on a new addition roof means water is already getting under the course.
• Moss or algae growth that keeps returning on the north slope. Austin’s humidity plus shade from mature live oaks creates the right conditions for algae. Tamko makes an algae-resistant line, but if the wrong granule spec went on, the growth keeps coming back and shortens the shingle life.
• Soft spots you can feel when walking the roof or inspecting from a ladder. That’s decking rot underneath the Tamko underlayment. It means moisture has been getting past the barrier for a while, and you’re into decking replacement territory before the new shingles can go down.

Replacement Cost & What’s Included

For an Austin home addition or ADU built with Tamko roofing and waterproofing, plan on $45,000 to $130,000 for the addition, or $90,000 to $220,000 for a complete detached ADU. What drives the number: the size and complexity of the roof on the new structure, whether you’re tying into an existing roof line or building a separate envelope, the insulation and HVAC requirements for our code climate, and the finish level inside. A simple bump-out with a straight roofline lands at the lower end. A full bedroom and bath with dormers, ducted HVAC, and a tie-in to an existing 60-year-old roof lands at the higher end.

What’s included in our pricing: the written quote covers the demo (if any), framing, roofing with the exact Tamko products listed, underlayment, flashing, insulation, drywall, paint, the connection detail work, and a written warranty on the whole project. If the price changes, we tell you before the work changes, not after. That’s the point of the written number. You get the invoice that matches the quote, and our 365-Day Done Right Promise behind it: if something fails inside the guarantee year, we fix it at no charge. Cambria, KraftMaid, and Silestone product lines are also available if the interior finishes move into kitchen or countertop territory.

DIY or Call Us?

For the roofing and waterproofing parts of a Tamko addition, this is not a do-it-yourself job. The safety risks are real: you’re working at height, near the roof edge, and the proper installation sequence for water shield, underlayment, and flashing is the difference between a watertight house and a mold problem in the wall cavity. One wrong overlap on the Tamko water shield at the transition point, and you’ll be opening up the ceiling inside the addition six months later to find the rot. That repair costs more than the original install.

What you can do safely: check your gutters for granule build-up, look for visible shingle damage after storms, and keep a photo record of any water staining you see inside. That gives us a head start when we come out to look. If you’ve got a failing connection point or an existing addition roof that’s showing its age, call (325) 225-5429 and ask for a free estimate. We’ll come out, look at the details, and give you a written price. Tell me what you need, I’ll tell you what it costs, and we’ll go from there.