Tamko Underlayment & Deck Repair Nationwide

Tamko Underlayment & Deck Repair: The Pasadena Owner’s Guide

If your Tamko roof system has a failing underlayment or a soft spot in the decking, the repair typically costs between $850 and $2,400 in Pasadena depending on how many square feet are affected and whether the deck plywood needs full replacement or just a patch. We stock Tamko-compatible underlayment on our trucks, and most deck repairs are completed the same day once we get the old material up and see what’s underneath. You’ll usually find out the hard way after a leak shows up on the ceiling, or during a re-roof when the crew pulls back a section and finds the underlayment has dried out, cracked, or separated at the seams.

Call (626) 657-5397

We’re an independent Pasadena roofing company, not affiliated with Tamko, but we’ve worked with their underlayment systems for years. What matters to us is matching the right material to your existing roof so water never gets a second chance at your decking.

Which Tamko Models This Applies To

Tamko makes several underlayment lines that end up on Pasadena homes, and the repair approach changes depending on which one you have. The two most common are TW Metal and Tile Underlayment (a reinforced felt) and Moisture Guard Ice & Rain (a peel-and-stick modified bitumen membrane). On older Pasadena roofs, especially craftsman-era homes that were re-roofed in the 1990s or early 2000s, we regularly see the original felt-based underlayment under Tamko shingles breaking down along the eaves and valleys long before the shingles themselves give out.

To identify what you have, look for the Tamko logo printed on the exposed underlayment edges in your attic, or check the original roofing invoice if you have it. The physical measurement matters too: Moisture Guard comes in 36-inch-wide rolls, while the felt underlayments are typically 36 or 40 inches wide. Here’s the compatibility gotcha most Pasadena homeowners don’t know: if your original underlayment is a non-Tamko felt, mixing in a Tamko peel-and-stick membrane in a repair area is fine, but the seams must be sealed correctly or water tracks sideways into the old material. We match what’s there, not what’s convenient to grab off the shelf.

For decking underneath, the question is usually plywood versus OSB. Most Tamko installations over the last two decades in Pasadena used either 15/32-inch plywood or 7/16-inch OSB. If the deck has started to delaminate from moisture, you can’t just nail new underlayment over it and call it done. The deck has to come up in those sections.

Signs Your Tamko Underlayment & Deck Repair Is Failing

• Water stains on the ceiling or upper walls after rain. This is the classic clue that underlayment has failed somewhere above. Underlayment is the last line of defense before water hits the deck, so a stain usually means the underlayment tore, cracked, or pulled away from a seam and water has been working through slowly.
• Spongy or soft spots on the roof deck when walked on. If you or a contractor feels give underfoot, the plywood or OSB has absorbed moisture and started to lose structural integrity. In Pasadena, this often happens near valleys and around penetrations like vents or skylights, where water pools during our heavier winter rains.
• Granules piling up in gutters or at downspout bases. While granule loss is often attributed to shingles, it can also signal underlayment breakdown underneath, especially if you’re seeing bare spots on the shingle edges near eaves. Once the underlayment starts disintegrating, the overlay shifts, and the shingles above take on more friction.
• Visible daylight through the attic roof boards. If you can see light through cracks or gaps from inside the attic, the decking has split, warped, or pulled back from the joints. This is a deck repair issue, not an underlayment issue, and it needs to be addressed before the rainy season in Pasadena kicks in around November.
• Peeling exterior paint or bubbling on the fascia boards near the roofline. When underlayment fails along the eaves, water runs down behind the gutters and into the fascia. Paint that won’t stay put in a specific area is often a roof leak hiding above it.

Replacement Cost & What’s Included

For a targeted Tamko underlayment repair on a Pasadena home, you’re generally looking at $850 to $1,400 for underlayment-only work on a 100 to 200 square foot area. If the decking underneath needs patching or full replacement, that adds $400 to $1,000 depending on how many sheets of plywood or OSB come up and whether the rafters or trusses need any reinforcing. Larger jobs, like replacing the entire underlayment layer during a full re-roof, run higher because the labor multiplies, but on a repair basis the price range above covers most of what we see in Pasadena neighborhoods like Bungalow Heaven, Madison Heights, and the hillside areas near the Arroyo.

Every Birchbark Roofing job includes a written price before any work starts, so you’ll see the exact number in dollars, broken down by materials and labor, before a tool comes out. And if the repair isn’t done right, our 365-Day Done Right Promise means we make it right at no charge. You’ll have the price in writing before we touch a single shingle.

DIY or Call Us?

Walking a roof deck is not something we recommend for homeowners, especially on a two-story Pasadena craftsman with a steep pitch. A fall is a fall, and soft decking makes the risk worse. What you can safely do is check your attic with a flashlight after a rain, photograph any new stains, and call us with what you see. Erik Lindgren has been diagnosing leak patterns for close to three decades, and he’d rather take the inspection walk himself than have you risk your neck.

Where DIY goes wrong with deck repair is the match: if you use the wrong thickness plywood or a non-compatible underlayment, you create a lip or a seam that water finds within a year. Then you’re paying twice. If you’re seeing the warning signs above, call (626) 657-5397 and we’ll schedule a walk-through.

FAQs