Johns Manville Insulation: 7 Cost-Controller FAQs (Asbestos, Calculator, and More)

I run procurement for a 140-person commercial construction firm. That means I write purchase orders for Johns Manville insulation, roofing membranes, and a hundred smaller building components—shower valves, chimney caps, you name it. Over seven years and roughly $2.3 million in tracked orders, I've learned where the hidden costs hide. This FAQ covers the questions I get asked most often by contractors and facility managers.

1. What about Johns Manville asbestos insulation? Is JM insulation safe?

This is the first thing people ask. When I started in this role, I assumed “Johns Manville asbestos insulation” meant I should avoid every JM product. That was wrong.

According to the EPA (epa.gov), asbestos was used in many building materials before the late 1970s. Johns Manville manufactured some asbestos-containing products back then, but stopped decades ago. Current JM insulation—fiberglass, mineral wool, polyiso board—does not contain asbestos. If you're working in a pre-1980 building, old pipe insulation might contain asbestos (not necessarily JM), so test before removing. New JM products are safe and compliant. I keep an EPA factsheet link in my procurement folder for exactly these conversations.

2. Does Johns Manville still sell asbestos-containing insulation?

No. Johns Manville's official website states that the company no longer manufactures asbestos-containing products. In fact, JM has produced non-asbestos insulation since around the late 1970s. The phrase “Johns Manville asbestos” is about history, not current inventory.

If a distributor ever tells you they have a “special old-style” JM insulation with asbestos available, walk away. It's impossible—and probably a scam. There's no legal market for new asbestos insulation in the U.S. I've never seen it in our supply chain, and I don't expect to.

3. How do I use the Johns Manville insulation calculator?

The JM insulation calculator on their website is a practical tool. You enter the area in square feet, choose your target R-value, and it suggests the product type and quantity.

We used it for a 12,000 sq ft warehouse roof last fall. The calculator said about 90 rolls of R-30 unfaced fiberglass, plus 6% waste. I ordered 8% waste because cuts and fumbles always happen. The estimate held up.

One caveat: the calculator assumes standard framing spacing. If your joists are unusual, adjust accordingly. Also, it does not calculate labor, fasteners, or adhesives. Don't rely on it for full project costing—use it to get in the ballpark. I don't have hard data on how it handles every assembly, but in our projects it's been within 5% of actual material.

4. What's the real cost of a shower valve? Why isn't the cheapest option cheaper?

You wouldn't usually search “shower valve” on a Johns Manville page, but renovation budgets include both. Here's a lesson that cost us.

A supplier quoted us a shower valve at $38—about $12 less than the name brand. What they didn't quote: a spring-loaded cartridge we had to buy separately, a different rough-in plate, and an extra hour of plumber labor because the trim didn't fit our existing box. After adding it up, the “cheap” valve cost 27% more than the transparent one. That's the hidden-cost trap.

The reliable vendor listed every component upfront. Now our procurement policy requires itemized quotes with model numbers. Ask “what's NOT included” before you ask “what's the price.”

5. Why should I budget for a chimney cap?

Because skipping it is textbook penny-wise, pound-foolish.

A few years ago, we finished a roof job and the property manager decided to save $80 by not installing a chimney cap. Six months later, rainwater and birds got into the flue. The service call, replacement damper, and debris cleanup came to $620. The owner ended up paying for the cap anyway, plus markup. Net loss: $540.

The simple lesson: if your project includes any exposed chimney, buy the cap. It's a small item, but it's insurance. I should add that JM roofing accessories don't include chimney caps—we source those separately. But the cost-control principle is the same: upfront clarity beats surprise repairs.

6. Does Johns Manville have a roofing cost calculator too?

Kind of. The insulation calculator covers insulation. For roofing membranes, JM provides technical data sheets, but most of us use those and ask distributors for a line-item breakout.

For roofing, I've learned to get quotes from three distributors and compare every line: insulation board, membrane, fasteners, adhesive, edge metal. Everyone discounts different lines. The lowest total isn't always the lowest “product price.” That's why transparency matters more than a headline number. The vendor who lists all fees upfront—even if the total looks higher—usually costs less in the end.

7. Where can I buy face paint? (Why is this in a JM article?)

Oddly, “where to buy face paint” shows up in our site's search terms alongside Johns Manville. I'm not a party supplier, but since I buy all kinds of things for our company, I can help: craft stores, party supply shops, and online retailers sell non-toxic face paint kits for $10–$25. For a company event, buy FDA-compliant brands and do a patch test first.

But if your search is actually about insulation, focus on the calculator and the R-values. The face paint question, I'll leave to the HR team. (And if you need a precise brand color match for paint, don't ask me—I only know Pantone numbers from old print specs.)

That's the list. The key is to manage total cost, not the sticker price. Ask what's not included. Verify current specs. And if you're sourcing JM products, use the calculator, read the data sheets, and get itemized quotes.