Knauf Attic Insulation: The Austin Owner’s Guide
We stock and install Knauf attic insulation throughout the Austin area, and most full attic replacement jobs run between $2,800 and $5,600 depending on square footage and the R-value you’re after. We carry Knauf blown-in fiberglass, batts, and rolls on the truck, so we can typically start the same day you call. The way most Austin homeowners discover their Knauf insulation has failed is blunt: the upstairs bedroom stops holding temperature, or the July electric bill climbs $80 a month without explanation.
Knauf is one of eight insulation brands we work with, and it’s a solid product. But in a Texas attic, even good insulation fails. The 140-degree summers cook it, blown-in material settles, and one badly placed roof leak can compress a whole section into uselessness. Glenn Hartley, who leads our Austin crew, has been in enough attics here to know the difference between insulation that’s still doing its job and insulation that’s just taking up space.
Key takeaways:
- Knauf insulation works on R-value, the measure of how well it slows heat moving through your ceiling
- Austin attics regularly hit 140 degrees in summer, which shortens the working life of any insulation, Knauf included
- Most replacement jobs are completed in one day, and we hand you a written price before anything starts
- The 365-Day Done Right Promise covers every Knauf install we do in Austin
Which Knauf Models This Applies To
Knauf makes three main attic product lines, and the details matter more than most people expect: EcoBatt (fiberglass batts and rolls), Insulation Board (rigid foam), and Jet Stream (blown-in loose-fill fiberglass). The key compatibility gotcha is this: blown-in Knauf and batt Knauf are not interchangeable in the same cavity. If your attic has settled Jet Stream and you shove batts over the top, you’ll create voids that let heat pour through. And if you compress Knauf batts into a too-shallow rafter bay, the R-value drops sharply. A batt labeled R-38 only delivers R-38 at full loft.
When you’re checking what you have, look for the Knauf marking printed on the kraft facing or the bag label from the original blow-in. Johansson, Knauf’s US manufacturing arm, prints the R-value and the product name clearly. If you can’t read it, measure the depth: blown-in fiberglass at 10-1/2 inches gives you roughly R-30; 17 inches gets you near R-49, which is what we recommend for Austin attics. If you’ve got batts, check whether they’re 2×6 or 2×8 cavity batts before buying any replacement. We’ll do that check for you on a free estimate visit, along with a full attic inspection.
Woolsey Insulation Austin is an independent installer and service provider, not affiliated with Knauf. We also keep Reflectix and other brand materials available as needed.
Signs Your Knauf Attic Insulation Is Failing
Most failures show up as heat transfer first and structural discoveries second. Here’s what we see in Austin homes:
- Upstairs rooms won’t hold temperature. The insulation has settled, compressed, or been displaced. Blown-in fiberglass settles over time; at 10 years old, it’s often lost 20 to 30 percent of its original loft.
- Ceilings feel warm to the touch at noon. Warm drywall means heat is moving through the attic floor. This is the clearest single symptom of insulation that has stopped doing its job.
- Electric bills spike in June and August. When your AC is running longer to offset attic heat gain, your insulation isn’t slowing transfer the way it should. In Austin, that difference can be $50 to $90 a month, June through September.
- You hear rodents overhead at night. Squirrels and roof rats shred fiberglass insulation for nests. If you hear scratching, there’s a good chance the Knauf material in one corner of your attic has been torn apart. We’ll tell you to handle the pest issue first, then we can replace the insulation.
- Visible dark spots or water stains on the insulation surface. A roof leak or AC condensate drip has soaked the material. Wet fiberglass insulation loses its R-value almost entirely and will never dry properly. Wet Knauf needs to be removed, not dried out, because it harbors mold.
Replacement Cost & What’s Included
Most Knauf attic insulation replacement jobs in the Austin area run between $2,800 and $5,600 for a typical single-family home up to about 2,200 square feet. Smaller attics can land around $2,200; larger or two-story homes with steep pitches can run past $6,000. What drives the range: the square footage of your attic floor, the R-value you’re targeting, how much old material needs to be vacuumed out first, and whether we’re adding new blown-in fiberglass or installing batts in tight rafter cavities.
| Job Item | Typical Range |
|---|---|
| Full attic blown-in Knauf insulation, R-49, 1,200 sq ft | $3,100 to $4,200 |
| Full attic blown-in Knauf insulation, R-49, 2,000 sq ft | $4,300 to $5,600 |
| Knauf batts in rafter cavities or knee walls | $4 to $7 per square foot |
| Removing old, wet, or pest-damaged insulation | $900 to $1,800 depending on depth and access |
Every Knauf job we do includes the same written guarantee: if the insulation fails within 365 days, we come back and fix it at no charge. That’s the Kingswell Guarantee, and it applies to every Austin install we do. Call (361) 418-9997 for an exact written quote before anything starts; estimates are free.
DIY or Call Us?
Here’s the honest split. What you can safely do yourself: inspect the attic for obvious problems. Look at the depth of the blown-in material, check for dark wet spots, listen for rodents. That’s wiring you’ve got up there. You can safely check your attic during cooler months, but don’t go crawling around in July. The attic temperature can hit 150 degrees, and heat exhaustion sets in fast at that heat. If you can feel a hot spot in your house, there’s a reason, and it’s usually something we can fix.
What usually goes wrong with DIY Knauf replacement: you buy the wrong R-value, you compress batts into the wrong cavity, you accidentally block soffit vents that your attic needs for airflow, or you disturb old insulation that contains contaminants you shouldn’t be breathing. Also worth saying plainly: blown-in insulation requires a machine. Most hardware stores rent them, but the learning curve on getting even coverage is steep, and an uneven install will leave you with the same hot spots you started with. For batts in a wide-open attic floor, a careful homeowner with a good mask and gloves can handle it. For knee walls, rafter bays, or any area with tight access, we’d rather see you call us. The written price we hand you up front means there’s no door surprise, and the 365-day guarantee means you won’t have to redo a failed DIY job on your own dime.
FAQs
Realistically, expect 15 to 20 years from Knauf fiberglass in central Texas, though we’ve pulled material out of attics that was 30 years old and still holding. Austin’s heat accelerates settling, so blown-in Knauf loses loft faster here than in cooler climates, and that lost loft is lost R-value. Batts and rolls last longer than blown-in because they don’t settle, but if a roof leak gets them wet, they’re done. Call (361) 418-9997 and we’ll tell you if yours is worth keeping or if replacement is the smarter move.
Often yes. If the existing Knauf is dry, not compressed, and there’s no pest damage, we can blow new Knauf fiberglass right over it. Adding depth gets you to the R-49 we recommend for Austin homes without paying for removal. But if the old material is wet, moldy, or shredded by rodents, it has to come out first. The written quote we give you before work starts includes whichever path applies to your attic, so there’s no up-charge discovered mid-job.
Most full replacements in Austin take one day, start to finish, including removal of old material and blowing or fitting the new Knauf insulation. Large custom homes with steep pitches or tight access can run into a second day. We’ll tell you the exact timeline in your written estimate, and we commit to an arrival window, no vague “we’ll be there sometime Tuesday.”
We keep Knauf blown-in fiberglass, EcoBatt rolls, and batts stocked on our Austin trucks. That means on most jobs we can start the same day we inspect the attic. If we need a specific size of batt or a quantity that exceeds what we carry, we typically have it from our local supplier within one business day. Call (361) 418-9997 and ask for a free estimate; we’ll confirm what we have on hand and what we’d need to order for your attic.
Written by Glenn Hartley, Owner, Woolsey Insulation Austin at Woolsey Insulation Austin, serving Austin and nearby areas.