Johns Manville Insulation & Roofing Products: 8 FAQs from a Buyer Who Learned the Hard Way

I’ve been handling Johns Manville product orders for about six years now. In that time I’ve placed hundreds of orders — and screwed up more than a few. Mis-specified insulation, ordered the wrong membrane thickness, assumed a historical product was still available (ugh). This article answers the questions I wish someone had answered for me back in 2019.

What kinds of Johns Manville insulation products are available?

JM’s insulation line is broad: fiberglass batts and rolls, spray foam (both open-cell and closed-cell), rigid board (polyiso, XPS), duct insulation, pipe insulation, and blown-in loose-fill. They also make GoBoard — a waterproofing backer board for tile showers — and commercial roofing membranes (TPO, PVC, modified bitumen). If you need thermal or acoustical insulation for a commercial or residential building, odds are JM has something. (As of March 2025, their product data sheets are freely downloadable on the JM website.)

I keep hearing about “Johns Manville Transite Pipe” — what is it, and can I still buy it?

Transite was a brand name for asbestos‑cement pipe JM manufactured from the 1920s until the 1970s. It is a historical product only. JM stopped making it decades ago, and modern JM products contain no asbestos. If you’re dealing with old Transite pipe on a job site, treat it as ACM (asbestos‑containing material) and follow proper abatement procedures. For new construction, you’ll use PVC, ductile iron, or other non‑asbestos alternatives. I once spent three hours on hold with a supplier asking for “JM Transite” before realizing my mistake (circa 2021). Save yourself the embarrassment.

Can I get Johns Manville products for a small project — like a single shower niche?

Yes, but you’ll need to find the right dealer. JM’s distribution network includes big-box lumberyards (Lowe’s, Home Depot) and independent supply houses. For a single shower niche, you can buy GoBoard sheets individually at a home center. That $40 order is absolutely worth their time. When I was starting my side business, the suppliers who took my $200 orders seriously are the ones I still use for $20,000 orders today. Small doesn’t mean unimportant.

What does “valve stem” have to do with Johns Manville?

Not much directly — but if you’re insulating a valve assembly, you may need pre‑formed pipe insulation around the stem area. JM makes fiberglass pipe insulation (Micro-Lok, Zeston) that can be cut to fit. I’ve seen installers miss the valve stem and leave an uninsulated gap that costs heat loss. On a large chilled‑water system I worked on (September 2022), three uninsulated valve stems caused $450 in extra energy costs per year. JM’s technical data sheets show how to fabricate removable valve covers.

Where can I buy Johns Manville products?

For commercial quantities, go through JM’s distributor network — ABC Supply, Beacon, or local insulation wholesalers. For residential or small jobs, Lowe’s and Home Depot carry JM fiberglass insulation and GoBoard. You can also order directly from some online retailers (e.g., Outlet Insulation, Insulation4Less). As of March 2025, JM does not sell direct to consumers. Pro tip: if you need exactly one roll of duct insulation, call a supply house — they often sell by the piece, even if their website says “bulk only.”

And where to buy Salt & Stone? That seems unrelated — should I ask a different vendor?

Salt & Stone is a sunscreen and skincare brand — not a building product. If you’re searching for “where to buy salt and stone” thinking it’s a building material, I’d guess you mean “salt and stone” finishes (e.g., stone veneer, salt‑based water softener media). Johns Manville doesn’t sell those. For sunscreen, check Sephora or the brand’s website. Just making sure we’re on the same page (a mistake I’ve made myself when searching for “cement board” under the wrong brand).

Is Johns Manville insulation worth the price for a small contractor?

I’ll be honest: on small orders you won’t get the same per‑unit price as a large fleet buyer. But JM’s product consistency and technical support often save you money downstream. I once ordered a cheaper brand of polyiso board for a tiny roof project — the facer delaminated, and I had to buy replacement board + pay extra labor. That $50 savings turned into $380 in redo costs (true story, Q1 2023). JM’s quality is generally reliable, and their data sheets are thorough.

What’s the #1 mistake you see people make with JM products?

Assuming the insulation R‑value per inch is the same across all JM boards. It’s not. Polyiso (e.g., JM Enery 3) has a higher R‑value per inch than XPS (Foamular) at low temperatures, but loses R‑value in extreme cold. I once spec’d XPS for a freezer application because it was cheaper — and got condensation on the surface. The JM tech rep (bless them) pointed me to the correct product. Lesson: read the technical bulletin (TB‑100 for insulation, as of January 2025) before ordering.