Boral Underlayment & Deck Repair Nationwide

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

If your Boral roof system has a failing underlayment or damaged decking, we install Boral-compatible underlayment and complete deck repair throughout San Antonio, with most jobs running between $850 and $2,400 depending on deck damage extent and square footage. We keep Boral-compatible synthetic underlayment and CDX plywood decking on our trucks for most San Antonio service calls, which means we can often complete the repair in a single visit. Homeowners usually discover the problem the hard way: a ceiling stain appears after a heavy San Antonio downpour, or during a re-roof, the old underlayment peels back like tissue paper and the decking underneath has rotted through.

Call (254) 276-4369

Boral roofing products were engineered for performance, but here in South Texas, the underlayment and deck take a beating that even the best materials can’t always shrug off. Intense UV exposure, hail, and the kind of humidity that makes August feel like a wet blanket all work against the layers beneath your visible roof. When those layers fail, the shingles or tiles above them lose their foundation. That’s the part of the roof most San Antonio homeowners never see until it’s too late, and it’s the part we spend a lot of our time fixing right.

Key Takeaways:

• We stock Boral-compatible underlayment and decking materials for San Antonio service calls.
• Installed repair costs in San Antonio typically run $850 to $2,400 depending on deck damage and square footage.
• Most underlayment and deck repairs are completed same-day once we’re on site.
• Every repair includes a written 365-Day Done Right Promise in writing before work starts.

Which Boral Models This Applies To

Boral’s roofing division produced several distinct product lines before their US roofing operations transitioned, and the underlayment and deck specifications varied by system. If your San Antonio home was roofed with Boral concrete tile, you’re most likely dealing with either the Boral CedarLite or Boral VillaTile profiles, both of which required a reinforced underlayment rated for the weight and thermal expansion of concrete. Boral steel roofing systems, including the Boral Steel line, used a different underlayment spec entirely, one designed to handle the expansion and contraction of metal panels under the Texas sun.

Here’s the compatibility gotcha most homeowners don’t know: Boral tile roofs in San Antonio were often installed with a two-layer underlayment system, and if only the top layer looks worn, the bottom layer may still be failing where you can’t see it. We don’t patch over old underlayment. We remove it down to the deck, inspect the wood, and start fresh. That’s the only way to know the system underneath your Boral roof is actually sound.

As for the deck itself, San Antonio homes with Boral tile almost always have either 15/32-inch CDX plywood or 1×6 spaced sheathing underneath, depending on when the home was built and which code cycle governed the original installation. We match the existing deck material and thickness unless the current deck fails inspection, in which case we bring it up to current San Antonio code before the new underlayment goes down.

Signs Your Boral Underlayment & Deck Repair Is Failing

• Water stains on ceilings or walls after rain. This is the most common first sign. It usually means the underlayment has a breach and water is traveling down through the deck and into the home. By the time you see the stain, the deck underneath is likely already softening.
• Visible daylight or sagging in the attic. If you can see light through the roof deck from inside the attic, or if the deck visibly sags between rafters, that section has failed structurally. In San Antonio’s humid climate, this is often from long-term, slow leaks that never showed up as a dramatic drip.
• Granules or tile fragments in gutters after storms. This tells you the top layer took a hit, but it also means the underlayment underneath has been exposed to weather. Once the protective top layer is compromised, underlayment degradation accelerates quickly.
• Musty attic smell or visible mold on rafters. Trapped moisture in a San Antonio attic during summer can turn a small underlayment breach into a mold problem within weeks. The deck holds moisture against the wood, and the heat does the rest.
• Cracked or lifted tile edges along the eaves. Boral tile is tough, but when the underlayment beneath it degrades unevenly, the tile bed loses its flat surface and tiles start to shift. This often shows up first at the roof edge where thermal movement is greatest.

If you’re seeing any of these, don’t wait for the next San Antonio gully-washer to confirm your suspicion. Water intrusion that reaches the deck means the repair scope expands every week it goes unaddressed.

Replacement Cost & What’s Included

For most San Antonio homes, Boral underlayment replacement with deck repair runs between $850 and $2,400 installed. The range depends mainly on how much decking has to be replaced, which we won’t know for certain until we peel back the old underlayment and inspect the wood. Here’s the honest breakdown:

• Underlayment only (small section, no deck damage): $850 to $1,200.
• Underlayment plus one or two sheets of decking replaced: $1,200 to $1,800.
• Larger deck sections, multiple sheets, or full slope replacement: $1,800 to $2,400, occasionally higher on steep or complex Boral tile profiles.

Every estimate is a written line-item price you’ll see before any work begins. The price we write is the price you pay, with no change orders and no surprise add-ons at the end. On Boral tile work specifically, we also account for tile removal and reset, which most general contractors don’t think about until they’re halfway through the job. That’s the kind of thing that turns a $900 quote into a $2,000 invoice when someone doesn’t know tile systems. We know tile systems. The written price stays the written price, and the repair is covered by our 365-Day Done Right Promise: if it’s not right within a year, we make it right, free.

DIY or Call Us?

For anyone with a Boral roof, leave the underlayment and deck work to a professional. This isn’t gatekeeping. Walking the deck of a tile roof is dangerous; one wrong step on a cracked tile can send you off the edge, and San Antonio’s steep pitches make it worse. Beyond the fall risk, removing Boral tile to access the underlayment requires knowing how to lift tiles without cracking the interlocking edges, and if you crack tiles, you’re now buying replacement tile too.

What you can safely do yourself is inspect the attic, note any water stains or sagging, and give us a call. The inspection from inside costs you nothing. The peace of knowing what’s happening under your roof, that’s worth the call. When we come out, every technician’s name and photo is sent to you ahead of the visit, and they’ll show you a photo ID badge at the door before stepping inside. If you’d rather check the attic with us, that’s fine too. Call (254) 276-4369 and we’ll set up a free estimate.

FAQs

Call for a Free Boral Underlayment & Deck Estimate in San Antonio

If your Boral roof is showing any of the warning signs above, or you just want a professional opinion before San Antonio’s next storm season tests it, call us at (254) 276-4369. A live person answers, day or night. We’ll schedule a time for a no-cost inspection, send you the technician’s name and photo before we arrive, and hand you a written estimate with a fixed price. No pressure, no surprises. Just an honest look at what’s happening under your roof and a plan to fix it right.

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