Johns Manville Attic Insulation Nationwide

Johns Manville Attic Insulation: The Houston Owner’s Guide

If you have Johns Manville attic insulation that’s failed or failing, we stock and install the full Johns Manville line, and most Houston attic insulation jobs run between $1,800 and $4,500 installed, depending on square footage, depth, and whether we’re topping off or removing old material. We do same-week installation in most Houston neighborhoods, and same-day emergency work when a ceiling has been compromised by a leak or animal damage. The way most owners discover their Johns Manville insulation has failed is simple: an energy bill that keeps climbing, a ceiling that feels warm in August, or a bedroom that never holds temperature no matter how low the thermostat goes.

Call (903) 447-8369

We’re independently owned and operated, and while we’re not affiliated with Johns Manville, we work with their products every week because they make a fiberglass batt and blown-in line that holds up well in Houston’s specific climate. Glenn Hartley, our owner, has been in the insulation business for over two decades and has spent years working across Houston, from older ranch houses in Meyerland to newer builds out past Katy. If we wouldn’t put it in our own attic, we’re not putting it in yours.

Which Johns Manville Models This Applies To

Johns Manville builds three main attic insulation product families you’ll find in Houston homes: the ComfortTherm batt line (the one with the white vapor-retarder facing), the Climate Pro blown-in fiberglass, and the older MR Faced batts that were common in late-90s and early-2000s builds. Most Houston attics we service fall into one of two buckets: blown-in Climate Pro installed over a layer of older batts, or ComfortTherm batts in the attic floor that have compressed or been pulled up during HVAC or wiring work.

The compatibility question with Johns Manville is mostly about R-value depth, not model-to-model matching. Blown-in fiberglass over existing batts is fine, but only if the existing batts still have loft. Once a batt gets compressed from foot traffic or soaked from a roof leak, it loses most of its R-value because the trapped air pockets are gone. That’s the biggest compatibility gotcha we see in Houston attics: a homeowner adds six inches of new blown-in over dead batts and wonders why the upstairs is still hot. Same with mixing Johns Manville batts with old rock wool or cotton batting from the 1970s. Air-sealing comes first, then depth, then material choice.

Signs Your Johns Manville Attic Insulation Is Failing

• Upstairs rooms run 5-8 degrees warmer than downstairs in summer. The attic floor insulation has compressed or shifted, letting radiant heat from the roof deck push through the ceiling below. This is the most common complaint in Houston from June through September.
• You can see bare joists or thin spots from the attic hatch. Insulation should sit at or above the top of the joists. If the joists are visible, you’re losing conditioned air straight through the ceiling.
• Dusty air and funky smells from upstairs vents. Old blown-in fiberglass breaks down over time, and Houston’s humidity accelerates it, especially when attic ventilation is weak.
• Rodent tunnels or nesting in the insulation. Rats and squirrels love blown-in fiberglass. Once they tunnel through, the material’s R-value drops sharply in those zones, and you’ll need removal and replacement, not just top-off.
• Water staining on the ceiling below the attic. A roof leak that soaks Johns Manville batts or blown-in fiberglass ruins the material permanently. Wet fiberglass doesn’t dry back to its original performance, and it’ll hold moisture against the drywall.

Replacement Cost & What’s Included

For a typical 1,500-square-foot Houston attic, full Johns Manville blown-in replacement runs roughly $2,200 to $3,800. A top-off over existing healthy insulation runs lower, around $900 to $1,500. Removal of failed material, especially water-damaged or rodent-contaminated insulation, adds $500 to $1,200 depending on how much is up there and how awkward the access is.

What’s included in our number: the removal of old material if needed, air-sealing around top plates, plumbing penetrations, and recessed light housings where safe, the new Johns Manville material blown or laid to your target R-value, and site cleanup. Every quote we give in Houston is a written price before any work starts, with a written guarantee included on the full installation. That’s The Kingswell Way: say the price, show up in the window, leave it cleaner than we found it, put the guarantee in writing, and come back if it fails. 365 days, in writing, included on every job.

DIY or Call Us?

You can safely check a few things yourself: look in the attic hatch with a flashlight to see if joists are exposed, look for water stains on the ceiling below, and check if the underside of the attic feels hot in the late afternoon, which it will in Houston no matter what. What you shouldn’t do is attempt removal of water-damaged or rodent-contaminated insulation without protective gear and a plan for disposal. That material holds mold spores, dust, and animal waste, and bagging it properly matters for the health of everyone in the house.

Blown-in installation looks simple, and DIY machines are available at home centers, but the math matters: you need to know your target R-value, account for the settling of blown-in fiberglass over the first year, and avoid covering soffit vents, which causes attic ventilation failure, which in Houston means mold. We fix a lot of DIY top-offs where the homeowner buried their soffit vents and the attic turned into a steam room. Call (903) 447-8369 and we’ll give you a straight assessment and a written price before anything starts.

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