Tamko Underlayment & Deck Repair Nationwide

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

If your Tamko roof is leaking, buckling, or showing soft spots, the problem usually isn’t the shingle you can see. It’s what’s underneath. We stock and install Tamko-compatible underlayment and decking repair materials across Miami, with most deck repairs running $850 to $2,400 depending on how much plywood has to come up. We carry the materials on our trucks, so for straightforward repairs we can usually handle the job in a single visit. Homeowners typically discover the failure after a heavy rain, when a ceiling stain shows up in a bedroom, or during a routine inspection when a roofer points out that the deck feels spongy underfoot.

Call (850) 753-2996

Here’s what most people don’t realize: Miami’s humidity attacks underlayment long before the shingles show wear. When the underlayment fails, water sits against the decking, the plywood rots, and by the time you see a shingle lifting, you’re already into deck replacement territory. This page tells you exactly what to look for, what it costs to fix, and how to know whether your Tamko system can be saved.

Key Takeaways:

• Tamko underlayment failure in Miami is almost always moisture-driven, not age-driven
• Most deck repairs in Miami run $850 to $2,400 installed, depending on square footage and rafter condition
• We stock Tamko-compatible synthetic underlayment and CDX plywood on our trucks
• Mercer Roofing Co Miami is an independent roofing contractor; we are not affiliated with Tamko, but we install and repair their systems daily
• Every repair comes with a written price before we start and a 365-Day Done Right Promise in writing

Which Tamko Models This Applies To

Tamko’s underlayment line breaks into two families: their synthetic products (TW Underlayment, Apex, and MoistureGuard) and their felt-based products (Proline and 30# felt). The synthetic lines are what we see most often under Tamko’s Heritage, Elite Glass-Seal, and Titan XT shingle systems in Miami. If you’re unsure what’s under your shingles, the label is usually visible from the attic on the underside of the decking, or printed on the underlayment edge at the eave line. A Tamko TW Underlayment roll is 48 inches wide and comes in 250-square-foot rolls. MoistureGuard runs a different spec: 39.4 inches wide with a 200-square-foot coverage, which matters because the overlap pattern changes and so does the material math.

The OEM-vs-aftermarket question comes up a lot. For underlayment, an aftermarket synthetic from GAF, Owens Corning, or CertainTeed will perform as well as Tamko’s own, as long as the install follows Tamko’s nailing pattern and penetration details. The decking is where we push back on aftermarket hardware. Miami’s building code requires minimum 15/32-inch CDX plywood for reroof decking in most of Dade County, and cheap sheathing warps within two seasons here. We standardize on 1/2-inch CDX as a floor and upgrade to 5/8-inch when the rafter spacing exceeds 24 inches on center. That’s a spec detail most quotes gloss over, and it’s the difference between a deck that lasts twenty years and one that sags by the third hurricane season.

Signs Your Tamko Underlayment & Deck Repair Is Failing

• Stains on ceiling drywall or around can lights. This is water that has already passed through the shingles, through the underlayment, and is now pooling on the decking. By this point the underlayment is compromised in that spot, and the decking beneath it is almost certainly wet.
• Shingles that look “pillowed” or uneven from the ground. When the decking swells from moisture, it pushes the shingles up in soft waves. In Miami, this shows up most often on west-facing slopes where afternoon sun bakes wet plywood.
• Granule loss concentrated at the eaves, not just age-related wear. Tamko shingles shed granules naturally, but when underlayment fails at the eave line, water runs under the shingle and accelerates granule stripping from beneath.
• A soft or bouncy feel when walking the roof. Spongy decking means the plywood has delaminated. Your underlayment is already gone in that section, and the deck is structurally compromised. This is not a caulk-and-pray situation; it’s a cut-out-and-replace.
• Attic mustiness or visible water marks on rafter tails. Miami’s humidity hides underlayment failures for months. If the attic smells like wet cardboard after rain, the underlayment is wicking moisture even if you can’t see daylight through the decking yet.

Replacement Cost & What’s Included

Here’s the straight number set for Miami, because you should know what to expect before you pick up the phone.

• Underlayment only (partial replacement, 200-400 sq ft): $480 to $900 installed
• Underlayment full replacement (average Miami roof, 1,800-2,200 sq ft): $1,400 to $2,800 installed
• Deck repair (1-3 sheets of plywood replaced plus underlayment patch): $850 to $1,900 installed
• Deck replacement (10+ sheets, full section): $2,200 to $5,600 installed

What drives the range: how many sheets of plywood have to come up, whether the rafters themselves show rot (which adds sistering), roof pitch, and access. A two-story tile-topped roof in Coconut Grove costs more to work on than a one-story ranch in Westchester. Every quote includes tear-off of the failed material, haul-away, new fasteners, underlayment, decking, and the written 365-Day Done Right Promise. That promise means if the repair fails within a year, we return and make it right, free second visit included. No fine print, no re-quote.

Grant Whitlock, who runs our Miami crew, walks every deck inspection himself. He’ll give you a number in writing before any work starts, and that number doesn’t change unless you ask for additional scope. Call (850) 753-2996 and ask for a deck walk. The estimate is free.

DIY or Call Us?

Let’s be honest about this part, because working on a roof in Miami is not the same as watching a tutorial filmed in Ohio. You can safely check a few things from the attic: look for water stains on the decking, feel for soft spots, and check whether your underlayment looks saturated or crumbly. That’s useful information for us.

What you should not do is pull shingles and try to patch underlayment yourself. This is steep-slope, fall-risk work, and if you miss a seam or nail through the wrong layer, you’ve created a leak where one didn’t exist. The decking itself is load-bearing: cutting into a rafter by mistake turns a $900 repair into a structural problem. We show up with harnesses, proper staging, and a crew that does this every week. If you want eyes on it first, call us. We’ll tell you honestly whether it’s a repair or a replacement, and you’ll have that in writing.

A roof shouldn’t be something you worry about – that’s our job.

FAQs

Get Your Free Deck Inspection in Miami

If water is getting under your Tamko shingles, waiting is the most expensive option. Rot doesn’t pause between hurricane seasons; it spreads under the decking and turns a patch job into a reroof. Call (850) 753-2996 to schedule your free estimate. You’ll get a written price before any work starts, a technician whose name and photo are sent to you before the visit, and a repair covered by our 365-Day Done Right Promise. That’s how we’ve done it across Miami since 2000, and it’s how we’ll do it for your roof.

Written by Grant Whitlock, Owner, Mercer Roofing Co Miami at Mercer Roofing Co Miami, serving Miami and nearby areas.