Johns Manville Attic Insulation: The Austin Owner’s Guide
We stock and install Johns Manville-compatible attic insulation across Austin, with most full-attic replacements running between $1,800 and $4,200 depending on square footage, existing insulation condition, and the R-value your home needs. We can usually be on-site within 24 to 48 hours for an assessment, and same-week installation is common once we’ve taken measurements. Most Austin homeowners discover their insulation has failed not by looking at it, but by feeling it: a bedroom that runs 10 degrees hotter than the hallway, an AC unit that never cycles off in August, or a monthly electric bill that jumped $80 with no other explanation. When that happens, the insulation isn’t doing its job anymore, and the fix usually means removing what’s there and starting fresh.
Here’s the quick version of what this page covers: which Johns Manville products we work with, how to tell if yours has failed, what replacement actually costs in Austin, whether you should touch it yourself, and how fast we can get it done.
- Replacement cost in Austin: $1,800 – $4,200 for a typical attic, fully installed
- What we install: Johns Manville fiberglass batts and blown-in loose-fill, plus compatible aftermarket options
- Lifespan reality: 15 – 20 years in Texas attic conditions, sometimes less with rodent or moisture damage
- Same-week availability: common for full replacements once measurements are done
Which Johns Manville Models This Applies To
Johns Manville makes two main product lines for attics: JM ComfortTherm batts (the ones wrapped in plastic, with an R-value printed on the facing) and JM Attic Pro blown-in loose-fill fiberglass. Both show up in Austin homes constantly, especially in builds from the mid-1990s forward. The Attic Pro line is what we see most often in older homes that were topped off at some point: it’s the white, fluffy loose-fill that settles over time and loses its loft.
Here’s the gotcha most homeowners don’t know: Johns Manville batts from the 2000s were often installed at R-30 in a 2×10 joist cavity, which met code back then but falls short of what Austin’s climate actually demands now. The Department of Energy recommends R-38 to R-60 for attics in our zone. So a homeowner can have “full” insulation that’s technically intact but still under-insulated by 20 to 50 percent. That’s not a product failure; it’s an installation standard from a different decade. When we assess an attic, we’re checking both condition and whether the R-value actually matches what an Austin summer requires.
Woolsey Insulation Austin is an independent insulation contractor, not affiliated with Johns Manville, so when we recommend a product it’s because it fits the house, not because we’re tied to one manufacturer. We also carry Reflectix radiant barrier for Austin attics where the bigger problem is radiant heat gain rather than conduction loss, and we’ll tell you if that’s the better first move for your specific roof.
Signs Your Johns Manville Attic Insulation Is Failing
- Uneven room temperatures between floors or across a hallway. Insulation doesn’t fail evenly. One failed section over a bedroom is enough to create a 10-degree split between that room and the rest of the house, even with a well-running AC system.
- Your HVAC runs constantly from June through September. The math is simple: when attic insulation loses its R-value, the AC has to work harder to hold the same indoor temperature. If your unit runs 14 to 16 hours a day during an Austin summer, your attic is often the culprit.
- You can see bare spots or compressed areas when you look across the attic floor. Blown-in Johns Manville fiberglass settles over time, especially in humid, hot attics. Water from a past roof leak compacts it like wet newspaper. Those compressed zones have almost no insulating value left.
- Rodent or pest activity in the attic. Squirrels and rats love Johns Manville batts for nesting. They tunnel through them, shred the facing, and leave urine-damaged material that loses its loft and carries odor. If you hear scratching overhead in the spring, the insulation probably needs replacing in those areas.
- Drafts near ceiling fixtures, can lights, or attic hatches. When insulation shifts or settles away from the building envelope’s edges, air moves through the gaps. A draft near a recessed light means the insulation around it has been disturbed or never properly sealed in the first place.
Replacement Cost & What’s Included
Most Austin attic insulation replacements we do run between $1,800 and $4,200. Here’s the breakdown of what drives that range:
| Scope | Typical Austin Price Range |
|---|---|
| Top-off blown-in over existing insulation (1,200 sq ft attic) | $1,200 – $1,800 |
| Full removal and replacement with JM Attic Pro blown-in (1,200 sq ft attic, R-38 to R-49) | $2,400 – $3,800 |
| Full removal and replacement with JM ComfortTherm batts (R-38), including air sealing | $3,000 – $4,200 |
| Rodent-damage cleanup, sanitation, full re-insulation | Adds $500 – $1,000 depending on extent |
Every quote we give is a written price before any work starts. That’s not a marketing line; it’s how we run every job in Austin. The price includes removal of failed material, haul-away, installation to the R-value we agree on, and a written 365-day guarantee. If it’s not right within a year, we come back and fix it at no charge.
DIY or Call Us?
Here’s the honest split. You can absolutely check your own attic: look for bare spots, feel for compressed zones, check whether the insulation comes up to or above the top of your ceiling joists. You can also measure the depth. Fiberglass depth to hit R-38 is about 10 to 14 inches depending on the product, and if you’re seeing less than that in an Austin attic, you’re under-insulated.
What we don’t recommend is removing or reinstalling it yourself. Old fiberglass insulation holds decades of dust, rodent waste, and irritants that cause real respiratory problems without proper PPE and containment. Working in a Texas attic in the summer is physically punishing, and the risk of stepping through a ceiling joist onto drywall is not hypothetical. If you want to know what you’re dealing with, we’re glad to walk the attic with you and show you exactly what we’re seeing. Call (361) 418-9997 and we’ll set a time.
FAQs
Fiberglass insulation doesn’t rot or degrade on its own, but in real Austin attic conditions – 140-degree summers, high humidity, the occasional roof leak – most JM insulation should be evaluated at the 15-year mark and replaced or topped off by year 20. Factors like rodent damage and moisture intrusion can shorten that window significantly. If yours is 15 or more years old, it’s worth having us look.
Sometimes yes. Small bare spots can be topped off with additional blown-in material, and a few compressed batts can be swapped out. But when more than a third of the attic shows settling, rodent damage, or moisture compaction, spot repairs are usually money that would be better spent on a full replacement. We’ll tell you which side of that line you’re on, and you’ll see it with your own eyes before we quote anything.
Most single-story Austin homes we do in one day. Two-story homes or jobs that include rodent sanitation and extensive air sealing typically take two days. We set a committed arrival window and hit it; the written quote includes the timeline we’re committing to.
We keep Johns Manville Attic Pro loose-fill and ComfortTherm batts stocked and ready in Austin, including the common R-values for our climate zone. If a specific product needs to be ordered for a specialty application, we’ll tell you that before you pay anything. Call (361) 418-9997 for an exact quote; estimates are free, and a real person answers the phone.
Written by Glenn Hartley, Owner, Woolsey Insulation Austin at Woolsey Insulation Austin, serving Austin and nearby areas.