Boral Underlayment & Deck Repair Nationwide

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

Boral underlayment and deck repair in San Antonio typically runs between $800 and $2,400 installed, depending on how much decking has rotted or delaminated and what your specific Boral system needs. We stock Boral-compatible underlayment and deck repair materials on our trucks, which means most jobs get done in one visit.

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Most San Antonio homeowners discover they have a problem the same way: a leak shows up on the ceiling after a hard Hill Country storm, or a roofer doing a shingle inspection points to soft spots. The underlayment and decking are the layers beneath your shingles. When they fail, the shingles above can look perfectly fine while water works its way into your attic. We’re an independent service provider, not affiliated with Boral, but we’ve repaired enough Boral systems across San Antonio to know exactly what fails and why.

Which Boral Models This Applies To

Boral’s roofing lineup includes their slate, shake, and barrel tile profiles, but the underlayment and deck concerns are shared across every system. The most common setups we see in San Antonio are Boral concrete and composite tile over a solid deck with Boral’s recommended underlayment.

The compatibility gotcha with Boral systems is fastener placement. Boral tiles are heavier than asphalt shingles, which means the decking has to be rated for the extra load. If a previous contractor swapped in lighter plywood or OSB than the original spec during a partial repair, you get nail pull-through and soft spots. We check the deck thickness against Boral’s installation requirements every time, because 7/16-inch OSB doesn’t hold a tile anchor the way 5/8-inch CDX plywood does.

For underlayment, you have a real decision. OEM Boral underlayment is engineered to match their tile profiles, but high-quality aftermarket synthetic underlayment from manufacturers like Owens Corning and CertainTeed often exceeds the spec and carries its own warranty. We’ll quote you both options with a written price for each, before any work starts, so you can choose with the numbers in front of you.

Signs Your Boral Underlayment & Deck Repair Is Failing

• Water stains on ceiling or attic sheathing. A brown ring or damp spot directly under the roof plane means water has already gotten past the tile, underlayment, and deck. By the time you see a stain indoors, the deck below that spot is usually compromised.
• Soft or spongy spots on the deck visible from the attic. If you can press a screwdriver into the wood sheathing from inside the attic, the deck is rotting. Boral tile can hide this for years, because the tile itself doesn’t sag the way asphalt shingles do.
• Delamination on the underlayment. Older felt underlayment bubbles and separates over time. If you can see wrinkled, peeling layers around penetrations or at the eaves, water has been getting between the layers.
• Cracked or sagging tile with no obvious impact damage. A Boral tile that cracks without a tree branch hitting it usually means the deck underneath has flexed. Tile doesn’t flex, so it cracks instead.
• Moldy or musty attic smell after storms. That odor is your first warning of chronic moisture. By the time you can smell it, the underlayment’s water-shedding ability is already shot.

Replacement Cost & What’s Included

For San Antonio homes with Boral systems, here’s what we typically see:

• Isolated deck repair (one or two sheets of plywood, new underlayment patched in): $800 to $1,300
• Underlayment replacement for a single roof plane (tile removed and reinstalled): $1,400 to $2,200
• Full underlayment replacement with deck repair on a two-story San Antonio home: $2,400 and up

The range comes down to three things: how much decking has to be replaced, how steep or cut-up the roof is, and whether the tile can be salvaged or has to be replaced. You’ll get a written line-item price before we start, and the number on the page is the number on the invoice. No surprises at the door. And every repair carries our 365-Day Done Right Promise: if it fails within a year, we fix it at no charge.

DIY or Call Us?

Underlayment and deck repair is not a project we recommend doing yourself. The hazards are real: you’re working at height on a tile roof, and tile roofs are slick. With a tile system, you also have to lift and reset the tile without cracking it, and Boral tile is not cheap to replace. One wrong foot placement and you’ve turned a $1,200 repair into a $3,000 job.

What you can do safely is check the attic after a storm, look for daylight coming through the deck, and note any soft spots or stains. That gives us a head start on the estimate. But the actual repair belongs to someone who does this every week. We’ll walk you through the photos before and after, so you know exactly what we found and what we fixed. Call (361) 209-8857 to schedule a free estimate.

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