Metal roofing
Architectural shingles
Tile roofing
GAF
Owens Corning
Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Boral Underlayment & Deck Repair: The Fresno Owner’s Guide
Boral underlayment and deck repair in Fresno typically runs $850 to $2,400 installed, depending on how much decking has to be pulled and replaced before new underlayment goes down. We stock Boral-compatible underlayment on our trucks and can usually get eyes on your roof the same day you call. Most Fresno homeowners discover the problem after a leak shows up on the ceiling, or when they’re up on the roof cleaning gutters and notice decking that’s gone soft underfoot.
What you’re dealing with is the layer between your roof’s structural deck and whatever Boral roofing product sits on top of it. When that underlayment fails, water gets to the deck. When the deck fails, it rots. And in a Fresno summer, that cycle moves faster than people expect because the attic heat bakes moisture out of wet wood and breaks the fibers down. Travis Oakley has pulled enough rotted deck sections in the Tower District to know what that looks like from twenty feet away. Tell me what you’re seeing and I’ll tell you what it actually means.
Which Boral Models This Applies To
Boral makes several roofing product lines that sit over underlayment, and the compatibility question is real. If your roof uses Boral concrete tile, Boral steel roofing, or Boral’s CedarLite composite shake, each one has different underlayment requirements based on weight and how the fasteners bite through. The model line matters less than what’s on the existing roof, because the repair has to match what was installed originally or exceed it.
The practical way to identify what you have is to look at the side of the tile or shake for a stamped marking, or check the original invoice from the install. If neither is available, our technicians measure the tile profile and deck spacing on site. For Boral concrete tile over plywood decking in Fresno, the underlayment is usually a high-temperature self-adhered membrane or a double layer of 30-pound felt, depending on when the roof was installed. Older Fresno homes, especially those built in the 1970s and 80s, often have a single layer of felt that’s now baked brittle and delaminating. The OEM-versus-aftermarket question matters here: Boral’s warranty requires underlayment that meets their published spec, but the decking itself is always structural OSB or plywood from lumber suppliers, not a Boral product. We use either as the situation calls for, and we’ll put that choice in writing before any work starts.
Styles & brands we work with






Signs Your Boral Underlayment & Deck Repair Is Failing
- Ceiling stains that appear after heavy rain, not during it. Water is pooling somewhere above the underlayment and then soaking through slowly. By the time it shows inside, the deck below has usually been wet for weeks.
- Soft spots or “spongy” areas when you walk the roof. That’s the decking delaminating from moisture. In Fresno, we see this a lot on north-facing slopes where dew sits longest and the wood never fully dries.
- Granules or concrete dust washing out of your gutters. The underlayment has failed and the underside of the Boral tiles or shakes is eroding as water runs beneath them. That material has to go somewhere, and your gutters are where it lands.
- Musty attic smell that gets stronger in summer heat. Wet decking is drying from below and the moisture is pushing into your attic space. That smell is usually worse right after the sun hits the roof for a few hours.
- Visible tears, wrinkles, or bubbling under the tile edges where the Boral product meets flashing or penetrations like vents and pipes. This is the most common failure point on Valley roofs because the heat expands and contracts underlayment at a rate that eventually splits it.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
For Fresno homeowners, here’s the range we quote on Boral underlayment and deck repair. The spread is driven by how much decking has to come out and whether we’re working around penetrations, valleys, or steep sections.
| Scope | Typical Installed Price |
|---|---|
| Underlayment replacement only, no deck work | $850 – $1,400 |
| Underlayment plus 1 – 3 sheets of decking | $1,200 – $1,900 |
| Underlayment plus extensive deck replacement (4+ sheets) | $1,800 – $2,400 |
These are installed prices, meaning they include materials, labor, removal of old underlayment, and haul-off. The price you get goes on paper before any work starts and it does not move at the door. Every Boral underlayment and deck repair we do carries the 365-Day Done Right Promise: in writing, for one full year, and if it fails within that period we come back and fix it at no charge.
DIY or Call Us?
What you can safely do as an owner is look. Get up on a ladder or walk the roof if you’re steady on your feet, and check for the symptoms we listed above. Take photos of anything that looks wrong, especially around flashing and penetrations. You don’t need to touch anything.
What we don’t recommend is pulling Boral tile or shake yourself to inspect the underlayment underneath. Concrete tile is heavy, and once you break the interlocking pattern, getting it back down correctly matters so it doesn’t blow off in a Fresno wind event or crack under foot traffic. Decking repair means structural work, and doing it wrong means another leak next winter. If you see the signs, call (559) 785-2160 and we’ll send a background-checked, uniformed technician to take a look. The estimate is free.
FAQs
Plan on 15 to 25 years for most Boral underlayment in Fresno’s climate. The high summer heat and UV exposure through tile gaps dry out felt and membranes faster than coastal California, and we’ve pulled 20-year-old underlayment in the Tower District that came off the roof in brittle sheets. If your roof is over 20 years old and you’re seeing any of the failure signs, it’s worth having someone look. Call (559) 785-2160 and we’ll give you an honest assessment, not a sales pitch.
Yes, if the failure is localized around a single penetration, vent, or valley, we can cut back to solid decking and splice in new underlayment with proper overlap. That said, if the underlayment is brittle over large areas, patching is a losing game because the new section won’t bond well to the brittled material around it. We’ll tell you which situation you have before you spend a dollar.
Most Boral underlayment and deck repairs in Fresno take one to two days, depending on decking replacement and weather. We don’t start pulling tile if rain is in the forecast within 48 hours. The price we give you accounts for the full scope, and we don’t change it halfway through.
Yes, our trucks carry high-temperature self-adhered underlayment, 30-pound felt, and structural decking in common Fresno thicknesses. If your roof needs a specific product we don’t have on hand, we source from our Boral supplier network and most specialty orders land the same week. We also work with GAF, Owens Corning, and CertainTeed underlayment lines when they’re the better match for the roof.
Brennan Roofing Co Fresno is an independent roofing contractor and is not affiliated with Boral. We install and repair Boral roofing products with materials sourced through our supplier network.
Call (559) 785-2160 to schedule your free estimate. You’ll get a live person on the phone, a written price before any work starts, and a full-year written guarantee on the work. That’s the Garrison Standard, and it’s the same on every job we do in Fresno.
Written by Travis Oakley, Owner, Brennan Roofing Co Fresno at Brennan Roofing Co Fresno, serving Fresno and nearby areas.