Johns Manville Insulation: An Honest Buyer's Guide from Someone Who Orders It

I've been ordering insulation for our company's commercial projects for about four years now. When I took over purchasing in 2020, one of the first decisions I had to make was choosing between the big names—Johns Manville, Owens Corning, CertainTeed. It can feel overwhelming, especially when you're just looking for a straight answer on which product won't cause headaches down the line.

In this guide, I'll walk through the questions I get asked most often by our project managers and the contractors we work with. Everything here is based on actual orders, install feedback, and a few lessons learned the hard way.

Is Johns Manville insulation any good?

Short answer: yes, it's a solid choice. We've been using their fiberglass batts and spray foam for medium-sized commercial retrofit jobs. From the outside, you might think all fiberglass insulation is the same. The reality is that JM's fiberglass has a consistent density that our installers appreciate—it cuts cleanly and doesn't sag as much in vertical cavities compared to some budget brands we tested.

I will say this: their Sprayed Fiberglass product (the ComfortTherm line) has been a standout for us. Less dust than traditional blown-in, and the thermal performance has held up well in a warehouse we did two years ago.

Who is a Johns Manville distributor near me?

This is the number one question I get from contractors. JM has a pretty wide distribution network, but it's not always as obvious as the yellow pages (showing my age there). The easiest route is their official distributor locator on the Johns Manville website—no login needed, just enter your zip code.

I've found that most major building supply houses carry JM products. Places like ABC Supply, Beacon, and some regional lumber yards stock their pipe insulation and duct liners. For the specialty stuff like vapor barriers or high-density board, you might need to call ahead.

One tip: if a local supplier says they "can get it," ask for a lead time. In 2024, we had a vendor tell us 3 days, but it turned into 2 weeks because they were ordering from a secondary warehouse. Confirming stock first saved us a scheduling nightmare (ugh).

How do I remove adhesive from insulation or surfaces?

This is a practical one. If you're doing rework or repairs, getting old adhesive off surfaces (and sometimes off the insulation itself) is a pain. The most frustrating part of this: using the wrong remover can damage the facing or the actual fiberglass matrix.

For JM's foil-faced products, I've found a few things that work without destroying the facing:

• Goo Gone (citrus-based): Safe for most facings. Spray, let sit for 5 minutes, gently scrape. Avoid heavy scrubbing.
• Isopropyl alcohol (91%): Good for small spots on cleanable surfaces. Evaporates fast, so you need to work quickly.
• Mineral spirits: Works on stubborn construction adhesive, but test on an inconspicuous area first—it can soften some facings.

One of my biggest regrets: I once let a contractor use a heavy-duty industrial degreaser on a JM duct liner to remove tape residue. It ate through the acrylic coating. We had to replace a 40-foot section. If I'd checked the MSDS first (which specifies avoiding strong solvents), we'd have saved $1,200.

Wait, is Johns Manville insulation the same as Owens Corning?

No, they're different companies, though they compete in many of the same categories. The "Johns Manville vs Owens Corning" debate is common.

Here's the honest breakdown based on what our installers tell me:

• Fiberglass Batts: Both are excellent. JM tends to have a slightly tighter fiber structure, which some guys say installs cleaner. Owens Corning's "Pure Safety" has a better-known brand ring to it.
• Spray Foam: JM (through its Probuilder brand) has a good closed-cell product. Their training support for applicators is top-notch.
• Pipe Insulation: JM's fiberglass pipe insulation is considered industry standard for commercial HVAC. It's what we use exclusively.

The cost difference is usually within 5-10%, depending on your distributor's pricing. I wouldn't lose sleep over it—just make sure you're getting current market pricing. (The price reference I have from a January 2025 quote showed JM fiberglass batts at roughly $0.65-0.85 per square foot for R-13, depending on volume.)

Does Johns Manville insulation contain asbestos?

This is an important question, and one that comes from historical context. Johns Manville did use asbestos in some of their products decades ago, primarily in pipe insulation and roofing materials manufactured before the 1980s.

Today, all Johns Manville insulation products are asbestos-free and have been for many years. They comply with all current OSHA and EPA regulations.

However, if you're working in an older building (pre-1980) and encounter insulation that looks like an old JM product—especially the white, fluffy, fibrous pipe wrap—it's wise to have it tested before disturbing it. The 'they don't make it like they used to' thinking can be literally hazardous here. That old stuff is a different animal entirely.

Two quick unexpected things to consider when buying JM insulation

Here are two things I learned the hard way that might save you trouble:

1. Check the facing type for your climate. JM makes foil-faced and kraft-faced batts. The wrong facing in a humid climate can cause condensation issues. Our project manager ordered foil-faced for an interior wall in a dry, conditioned space—expensive mistake that required a re-order (ugh). Check the JM product data sheet for the recommended facing for your application.

2. The 'R-value per inch' can vary by product line. This is true of all brands, but it's especially important with JM's various fiberglass densities. Don't just order by R-value; check the required thickness to fit your cavity depth. We once ordered R-21 batts that were 5.5 inches thick, but our studs were only 3.5 inches deep. That was a frustrating return (to put it mildly).

This worked for us, but our situation was a mid-size commercial contractor with consistent ordering patterns. Your mileage may vary if you're a small homeowner doing a one-off attic job or a large industrial project with specific fire codes. If you're dealing with a large-scale project, the calculus on bulk pricing and delivery logistics might be different. Always double-check with your local distributor for current stock and pricing.