Knauf Attic Insulation Nationwide | Walt’s Insulation

Knauf Attic Insulation: The San Antonio Owner’s Guide

We stock and install Knauf attic insulation throughout San Antonio, with most complete attic installs running between $1,800 and $4,200 depending on square footage, existing insulation condition, and the Knauf product line you choose. We keep Knauf EcoBatt and Jet Stream blown-in fiberglass on hand across Bexar County, so we can usually start within a few days, not weeks. Most homeowners figure out their insulation has failed when the upstairs rooms won’t hold temperature no matter what the thermostat says, or when the July electric bill arrives and looks like a car payment. The good news: Knauf insulation is one of the more forgiving products to match and replace, assuming you know what you’re looking at and what San Antonio’s humidity does to it over time.

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We’re an independent installer, not affiliated with Knauf directly, but we’ve been working with their products since Walt Brenner started this business in 2000. The one down the road, as we like to say. We answer the phone live, 24/7, and we’ll tell you straight whether you need a top-up or a full removal and reinstall.

Which Knauf Models This Applies To

Knauf makes three attic products we see regularly in San Antonio homes: EcoBatt (batt insulation with ECOSE binder), Jet Stream (blown-in loose-fill fiberglass), and the older Performance+ batts that predate the ECOSE line. Here’s the compatibility gotcha most homeowners don’t know: EcoBatt is a different binder chemistry than the older Performance+, and they don’t mix well if you’re topping up an older batt job. The brown ECOSE batts are formaldehyde-free and handle San Antonio’s humidity better than the older yellow fiberglass from the pre-2008 era. If your attic has yellow batts that crumble when touched, that’s likely original-construction material that’s reached end of life, not something you can simply layer over and call done.

For blown-in, Jet Stream comes in two coverage ranges: R-30 (about 8.5 inches settled) and R-38 (about 10.5 inches settled) for attic floors. San Antonio sits in IECC climate zone 2A, which calls for R-30 to R-60 in attics. We typically recommend R-38 minimum given our heat load, and R-44 to R-49 when the budget allows, because the difference shows up on your summer bill within two years. When you match Knauf products, the label matters less than the settled depth and the R-value actually delivered. We check both before quoting anything.

We also keep Reflectix radiant barrier on the truck for attics where the heat gain comes as much from the roof deck as the insulation gap. That’s a different fix than replacing Knauf, but it’s often the missing piece when blown-in fiberglass alone isn’t enough.

Key takeaways:

• Knauf EcoBatt and Jet Stream are current products; Performance+ is the older line, and it won’t play nice as a top-up target.
• San Antonio building codes call for R-30 minimum in attics; our heat argues for R-38 or better.
• If you’re unsure what’s in your attic, we’ll identify it during the estimate. No guesswork, no upselling.

Signs Your Knauf Attic Insulation Is Failing

• Upstairs rooms run 8 to 12 degrees warmer than downstairs in summer. This happens when fiberglass settles or compresses over time, losing its loft and the air pockets that do the insulating. In San Antonio attics, heat also degrades the binder, especially in sun-baked sections near the roof deck.
• Your AC runs constantly between 2 p.m. and 8 p.m. That’s when attic temperatures peak here, often hitting 140 degrees or more. When insulation isn’t doing its job, the ceiling becomes a heat radiator pushing hot air down into the living space, and your system never cycles off.
• You find damp or stained batts near soffit vents or AC ducts. San Antonio’s humidity causes condensation in under-ventilated attics, and once fiberglass soaks up moisture, its R-value drops significantly. This is a venting problem as much as an insulation problem. We address both when we see it.
• Electric bills have crept up 20% or more over the same period last year. If the roof, AC, and appliances haven’t changed, the insulation usually has. Fiberglass doesn’t fail gracefully, it fails gradually, and the only way you notice is the bill.
• You can see gaps, thin spots, or animal trails in the attic floor insulation. Rodents love tunneling through blown-in fiberglass, and every tunnel is a thermal bypass. Beyond replacing the insulation, we’ll talk about rodent proofing so you’re not paying for the same job twice.

Replacement Cost & What’s Included

For a standard San Antonio single-story home around 1,500 to 2,000 square feet, a full Knauf Jet Stream blown-in reinstall to R-38 typically runs $2,200 to $3,600, including removal of old material and disposal. A top-up over existing insulation that’s still dry and structurally sound runs $1,100 to $1,800. EcoBatt roll installations land between $1,500 and $2,800 depending on attic access and whether we’re working around ductwork. What changes the price the most is the condition of what’s already up there: if it’s water-damaged or rodent-soiled, it costs more to remove, and skipping that step means whatever we put on top fails early too.

Every estimate includes the full job: removal if needed, air sealing around penetrations where practical, the Knauf product itself, labor, cleanup, and verification of settled depth. You get a written price before we start, and the work is covered by our Done Right Promise, a lifetime workmanship guarantee. If it’s not done right, we make it right. No runaround, no fine print games. We also offer a free second opinion on any written estimate, and there’s no trip charge in our service county. Seniors and veterans get 10% off, always.

DIY or Call Us?

Insulation is one of those jobs where the danger isn’t as dramatic as garage springs or electrical panels, but it’s still real. Attics in San Antonio hit 140 degrees for four months a year, and heat exhaustion catches people who think they’re just going to “roll out a few batts” on a Saturday morning. If you want to check what’s up there, grab a flashlight and look from the attic access: check for settled depth, dark stains, and animal sign. Beyond that, blown-in requires commercial equipment and a second person feeding the hopper, and EcoBatt installs mean working around trusses, wiring, and ductwork in tight spaces. The most common DIY failure we see is someone who installs batts over old, damp material and creates a mold situation that costs twice as much to undo. For anything beyond a visual check, call us at (866) 751-4428 and we’ll send a technician who does this every week, not once a decade.

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