Tamko Underlayment & Deck Repair in San Antonio, TX

Tamko Underlayment & Deck Repair: The San Antonio Owner’s Guide

Tamko underlayment and deck repair in San Antonio typically runs $1,200-$2,800 installed, depending on how much decking has rotted through and whether we’re matching existing Tamko Heritage or Titan XT shingle lines. We stock Tamko-compatible synthetic underlayment and 1/2-inch CDX plywood on every truck, and most deck repairs are completed same-day. Homeowners usually discover the problem after a hard rain, when water spots bloom on the ceiling or they notice a soft, spongy feel walking the roof during gutter cleaning.

Call (833) 756-5022

Which Tamko Models This Applies To

This applies across Tamko’s full residential line: Heritage, Heritage Vintage, Heritage Woodgate, Titan XT, and the discontinued Elite Glass-Seal lines still found on older San Antonio homes in neighborhoods like Monte Vista and Alamo Heights. The key compatibility issue is underlayment weight and permeability rating. Tamko’s current synthetic underlayment is rated at 10 square per roll with a 16 mil thickness; substituting a lighter 8 mil generic voids the shingle warranty and creates a mismatch in how the deck breathes during our humid Gulf Coast summers.

To identify what you have, check the shingle bundle label in your garage or attic stock, or look for the Tamko lot number stamped on the shingle back. If your home was built between 1985 and 2005 and never re-roofed, you likely have organic felt underlayment that has dried to the point of cracking, especially in south-facing sections where San Antonio sun exposure peaks. We carry both Tamko-branded synthetics and a heavier 20 mil aftermarket equivalent that meets Tamko’s spec for wind warranty continuity. The OEM part guarantees color-match and exact permeability; the aftermarket saves roughly 15 percent with no practical performance loss in our climate. Ridgeline Roofing Co. of San Antonio is an independent service provider, not affiliated with Tamko.

Signs Your Tamko Underlayment & Deck Repair Is Failing

• Water stains on ceiling drywall, especially after wind-driven rain. The underlayment has torn at valleys or penetrations, and water is tracking along the deck boards until it finds a fastener hole. In San Antonio’s spring storm season, this accelerates because wind lifts shingles enough to expose compromised underlayment.
• Soft or springy spots when walking the roof. The OSB or plywood deck has absorbed moisture through failed underlayment and begun delaminating. On older homes in Beacon Hill and King William, we’ve found 3/8-inch plywood that was under-spec from the start and rots through faster.
• Shingle granules collecting in gutters with black substrate visible. This often means the underlayment has baked and cracked underneath, allowing heat transfer that degrades the shingle mat from below. South Texas UV exposure turns cheap felt brittle in seven to ten years.
• Musty attic smell or visible mold on rafter undersides. Failed underlayment is no longer blocking moisture vapor. Our humidity hangs above 60 percent for months; without a functioning vapor barrier, the deck becomes a moisture sink.
• Nail pops or shingle tabs lifting in straight lines. The deck has swelled and contracted enough to push fasteners out. This happens when plywood has cycled through wet-dry seasons with compromised underlayment, common in homes near the San Antonio River basin where nighttime condensation is heavier.

Replacement Cost & What’s Included

What drives the range: deck material cost has climbed 40 percent since 2021, and accessing steep pitches or multiple stories in Terrell Hills or the Dominion adds labor hours. Our quotes include removal of failed materials, installation of Tamko-compatible synthetic underlayment, CDX plywood cut to match existing thickness, ice and water shield at valleys and penetrations, and reinstallation of matching shingles. The 90-Day Done Right Promise covers all workmanship; if a seam lifts or a nail backs out, we make it right with no paperwork and no arguing. The number on the estimate is the number on the invoice.

DIY or Call Us?

There is nothing wrong with walking your attic with a flashlight to confirm where the leak tracks. Look for darkened deck boards, water trails on rafters, or daylight showing through. But once you’re on the roof surface, the risks stack fast. Decking replacement involves working on an open frame with no solid footing, often at height, with pneumatic tools and exposed edges. We’ve seen homeowners in San Antonio step through rotted 3/8-inch decking that looked sound from below.

Underlayment installation looks simple until you hit the details: proper overlap at seams, integration with step flashing around chimneys, and sealing plumbing boots without distorting the collar. Get any of these wrong and you’ve bought yourself a repeat leak, usually discovered during the next hard rain. We carry the materials, we match the Tamko spec, and most repairs finish in one day. Call (833) 756-5022 for an exact quote - estimates are free, and a live person answers around the clock.

FAQs