Tamko Underlayment & Deck Repair Nationwide

Tamko Underlayment & Deck Repair: The Los Angeles Owner’s Guide

If your Tamko roof is leaking or you see water staining on ceilings, the underlayment or decking beneath the shingles has likely failed. We stock Tamko-compatible underlayment and repair decking on our trucks across Los Angeles, and most underlayment replacements on a Tamko roof run $450 to $1,400 installed depending on how many squares of roofing material need to be lifted and relaid. That price covers removing the old underlayment, replacing any rotted deck sections, installing the new Tamko-rated barrier, and putting everything back watertight. The way most Los Angeles homeowners discover this problem: a water stain appears on the ceiling after a heavy rain, or a roofer doing a routine inspection finds soft decking under the shingles that’s been quietly rotting for years.

Call (945) 303-9821

Which Tamko Models This Applies To

Tamko underlayment and deck repair applies to any Tamko shingle system: Heritage, Heritage Premium, Elite Glass-Seal, and StormFighter IR all rely on the same underlayment layer to protect the deck beneath. The gotcha most Los Angeles owners don’t know: Tamko’s warranty on the shingles only pays out if the underlayment below meets their spec. We see homeowners hold up a warranty claim because a previous contractor slapped generic felt over a deck that needed Tamko’s synthetic underlayment instead. Identifying what’s on your roof is straightforward – look for the Tamko logo printed on the felt or synthetic roll, measure the overlap at the seams (Tamko synthetic lays at a 4-inch overlap, not the 2-inch common with cheap felt), and note whether you’re looking at organic or fiberglass mat. Tamko’s synthetic underlayment comes in 10-square rolls, roughly 4 feet wide by 250 feet long, and the fiberglass-backed version handles Los Angeles sun exposure far better than standard asphalt felt. OEM Tamko underlayment is what we’ll recommend for any roof still under the manufacturer’s warranty period. After the warranty expires, a high-quality synthetic equivalent from GAF, Owens Corning, or CertainTeed meets or exceeds Tamko’s spec and can save you 15 to 20 percent on materials.

Signs Your Tamko Underlayment & Deck Repair Is Failing

• Water stains on ceilings or walls, especially after Santa Ana wind-driven rain. Driving rain at an angle pushes water under shingles and down through cracked underlayment where a straight-down rain won’t. If stains show up only on one wall, the underlayment seam above that wall is the likely entry point.
• Shingles lifting or curling at the edges, with dark felt visible underneath. Once the underlayment dries out and shrinks, it pulls at the shingle nails and loosens their grip. In Los Angeles heat, this happens faster on south-facing slopes that bake from noon to sunset.
• Soft spots when the roof is walked. If a section of deck feels spongy underfoot, the wood has absorbed water long enough to lose its structure. By the time you feel it from above, the underlayment above that spot has been compromised for months, often years.
• Granules from your shingles accumulating in gutters, with bare patches starting to show. Failing underlayment causes shingles to flex and wear unevenly, shedding granules faster than they should. We see this on Tamko roofs in the San Fernando Valley far more often than on coastal homes, simply because the heat cycles are harsher.
• Visible water or damp insulation in the attic, directly under the roof deck. This means water has passed through both the shingle layer and the underlayment, and is now sitting on your deck. If the deck is holding water long enough to soak the insulation below, you’ve already got some level of rot starting.

Replacement Cost & What’s Included

In Los Angeles, Tamko underlayment and deck repair pricing breaks down like this: underlayment replacement alone, including lifting and relaying the existing shingles, runs $450 to $900 for a typical single-story home section. If the decking below needs partial replacement, budget an additional $80 to $150 per 4×8 sheet of plywood or OSB. A full deck replacement on a small roof, where the entire roof is stripped, redecked, and a new Tamko underlayment goes down before shingles are reinstalled, starts around $1,200 and climbs based on roof size. What drives the range: roof pitch (steeper roofs require more safety setup and slower work), number of valleys and penetrations, how much of the deck needs cutting out, and whether your shingles can be reused or have reached the end of their life. Every estimate includes the materials, labor, haul-away of old underlayment and rotted deck sections, and a written guarantee on the repair work itself, delivered before our crew leaves the property. No change orders, no surprise line items added at the door. Greg Holloway put that rule in place years ago and it’s never been bent: know the price before the first tile moves.

DIY or Call Us?

What you can safely do yourself: check your attic for water staining after the next rain, clear gutters so water isn’t backing up under the shingles, and note which rooms below the roof show discoloration. What you shouldn’t do: pull up shingles to peek at the underlayment. Roof work on a pitched Los Angeles roof, especially repairing decking, means working at height with tools and materials that can slide. A fall from a single-story roof in Los Angeles results in a hospital trip more often than homeowners like to admit, and a bad DIY patch leaves the deck exposed to the next rain. Roof decking that’s rotten needs to be cut out carefully so the load of the roof transfers properly to the remaining structure – if you cut the wrong section or sister a joist badly, you’ve created a structural issue that costs far more to undo than the original repair would have. If you suspect underlayment or deck damage, call us at (945) 303-9821 and we’ll send someone out to inspect it, explain what we found in plain language, and hand you a written price before any work starts.

FAQs