Tamko Underlayment & Deck Repair Nationwide

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

We stock and install Tamko-compatible underlayment and deck repair materials across San Antonio, with most underlayment replacements running $1,800 to $4,600 installed depending on roof size and deck condition. Our trucks carry Tamko TW Underlayment, Moisture Guard, and deck replacement boards, so most jobs are completed same day once we’re on-site. Homeowners usually find us when they’ve spotted a leak near a valley or felt spongy decking underfoot in the attic, and they want a crew that matches the right Tamko product to the original system instead of slapping on whatever’s cheapest.

Call (903) 354-7802

Here’s what to know before you call: Tamko makes the underlayment, but the deck underneath it is the structural layer that holds everything together. When one fails, the other is usually not far behind. We’ll walk you through both.

Key Takeaways:

• We install Tamko TW Underlayment, Moisture Guard, and Apex underlayment systems, plus deck repair and replacement
• Most San Antonio underlayment and deck repairs run $1,800 – $4,600 installed
• You’ll get a written price in dollars before we touch the roof, no exceptions
• We’re an independent roofing company, not affiliated with Tamko, and we work with GAF, Owens Corning, CertainTeed, and other major brands too

Which Tamko Models This Applies To

Tamko’s underlayment line breaks into a few families, and matching the right one matters more than most contractors admit. The most common in San Antonio is TW Underlayment, a fiberglass-reinforced asphalt product available in two grades: the standard TW (25 mil) and TW Metal & Tile (40 mil) for higher-temperature applications under metal and tile roofs. We also see Moisture Guard, which is Tamko’s self-adhering ice and water shield, and Apex, their synthetic underlayment with a slip-resistant coating.

The compatibility gotcha we run into regularly: if your original roof used a self-adhering product like Moisture Guard in valleys and around penetrations, swapping in a cheaper #15 felt there is a downgrade, not an upgrade. San Antonio’s heat plus our occasional hailstorms push moisture into places felt simply can’t hold. We match the original spec unless you’ve explicitly asked us to upgrade it.

How to identify what you have: look at the exposed underlayment at the eaves or in the attic. TW Underlayment has a white or gray fiberglass mat face with Tamko printing every few feet. Moisture Guard is a thick, rubbery sheet with a release film on top. Apex looks like a bright synthetic fabric, often white or gray with printed grid lines. If you can’t tell, we’ll identify it in under ten minutes from a single trip into the attic or a look at the rakes.

On the OEM versus aftermarket question: for underlayment, we use Tamko products when the roof is a Tamko system and you want the manufacturer’s warranty to stay intact. For deck repair boards, there’s no such thing as “Tamko decking” – decking is structural plywood or OSB, and we source it locally to match your existing thickness, typically 1/2″ or 5/8″ in older San Antonio homes, and 7/16″ OSB in newer construction.

Signs Your Tamko Underlayment & Deck Repair Is Failing

• Water staining on ceiling drywall or around vents. This usually means moisture has worked past the underlayment and soaked into the deck. By the time you see a stain, the deck board beneath that spot has been wet for weeks or months.
• Spongy or bouncy sections when walking the roof. If a roofer’s foot sinks even slightly, the deck has lost structural integrity. In San Antonio attics, sustained heat accelerates OSB delamination once moisture gets in, because hot air bakes the glue layers until they separate.
• Visible underlayment tears, ripples, or exposed seams from the ground. Tamko underlayment should lie flat and tight. Ripples mean the fasteners have backed out or the adhesive has failed, and now wind-driven rain has a path under your shingles.
• Granules collecting in gutters alongside dark underlayment flecks. Shingle granule loss is normal over time, but underlayment particles in the gutter mean the underlayment itself is degrading from sun exposure at the eaves or rakes.
• Musty attic odor after rainfall. Smell is one of the first indicators of deck saturation, often before water visibly drips. Wet OSB in a closed San Antonio attic feels like a greenhouse and smells like one too.

Replacement Cost & What’s Included

Here’s the straight number range for San Antonio: a deck repair section of 2 – 4 sheets runs $600 – $1,800 installed. Full underlayment replacement on a typical 1,800 – 2,400 square foot roof runs $2,500 – $4,600, with tile or metal roofs on the higher end because they require the heavier 40-mil Tamko TW Metal & Tile. Deck replacement adds material cost per sheet, currently running $75 – $110 per 4×8 sheet for 5/8″ CDX plywood or OSB in our local market.

Every quote includes tear-off of the failed underlayment, deck inspection with documented photo notes, replacement of any unsound boards, new Tamko underlayment installed to current code, and full clean-up. You’ll see the line items before you sign: materials, labor, deck boards if needed, and disposal. No change orders after we start unless you ask us to expand the work.

The work is covered by our 365-Day Done Right Promise: if it’s not right, we make it right. Erik Lindgren’s crew doesn’t hand you a surprise number at the end of a job, because the number was already in writing before the first truck pulled up.

DIY or Call Us?

There’s a surface-level check and a real repair, and they’re different jobs. You can safely do the surface-level check from the ground or from inside your attic: look for stains, check for daylight through the deck, feel for spongy boards, and take photos of anything you find. That tells you whether you need us. It doesn’t fix anything.

The actual replacement means working on a roof deck, pulling nails and underlayment, and sometimes finding rotted sheathing that needs cutting out. A missed nail through a hidden wire in the attic, or a wrong step through a soft board, is a hospital bill waiting to happen. And if you’re not matching the underlayment to the Tamko system spec, you’re building a future leak right into the repair. We’d rather do it once with the correct materials and the correct fall protection.

If you’ve got signs of failure, call (903) 354-7802 and we’ll give you a written price before any work starts. A written price and a straight answer – that’s where we start.

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