Marinite® Calcium Silicate Insulation
— Grades, Specs, and What Comes Next

AWMCO has published detailed Marinite® replacement and specification comparison guides for each Marinite grade, including equivalent Super Firetemp® and Promat® materials. Each page features side-by-side specification tables, density and temperature comparisons, application compatibility guidance, product selection recommendations, and FAQs to help users evaluate and select the best Marinite alternative or substitute material for their application.

BNZ Materials, the sole manufacturer of the Marinite product line, has permanently ceased its Marinite production operations. There is no alternative manufacturer of Marinite — the brand is discontinued. Buyers who have historically sourced Marinite from BNZ distributors or directly are now competing for a finite pool of remaining inventory.

When AWMCO's remaining BNZ inventory sells through, Marinite will no longer be available from any source. Buyers who need ongoing supply of calcium silicate board in the same density and temperature range will need to qualify a replacement product. AWMCO recommends Super Firetemp and Promat products as the primary ongoing alternatives. Super Firetemp is stocked monthly and Promat products can be ordered as required. Between both manufacturers, they cover most Marinite grades and application requirements.

AWMCO cannot guarantee how long current Marinite inventory will last. Demand has increased significantly since BNZ's production facility closure announcement. Buyers who have immediate or near-term project requirements should order now. For long-term or recurring supply, transitioning to Super Firetemp, Promat or another calcium silicate insulation is strongly recommended.

Super Firetemp is a calcium silicate insulation board manufactured by Johns Manville, meeting ASTM C656 Type II standards. AWMCO stocks five Super Firetemp grades covering densities from 20 to 55 pcf and service temperatures up to 1800°F — spanning the full range of Marinite I, C, P, and A applications. Super Firetemp is available with monthly restocking, making it the long-term sourcing solution for buyers transitioning away from Marinite.

•      Non-asbestos, non-combustible — same product category as Marinite

•      ASTM C656 Type II compliant — meets engineer specification requirements

•      Multiple density grades — 20, 28, 35, 40, and 55 pcf

•      Rated to 1700°F–1800°F depending on grade

•      Custom cutting available — same sheet sizes as Marinite

•      Monthly restocking — reliable ongoing supply

Marinite is a structural calcium silicate insulation board developed for high-temperature industrial applications. It is non-asbestos, non-combustible, and machinable — it can be cut, drilled, and fabricated with standard woodworking tools. Marinite boards are rated ASTM E84 Flame 0 / Smoke 0, and most grades carry published electrical insulation data, making them a common specification for enclosures and electrical housings operating at elevated temperatures.

Marinite is a calcium silicate board — a composite of calcium, silica, and reinforcing fibers, formed into rigid boards under heat and pressure. It contains no asbestos and no gypsum. The result is a dimensionally stable board that maintains structural integrity and insulating performance at temperatures up to 1500°F, depending on grade.

Marinite is used across industrial and commercial applications wherever non-combustible structural insulation is required. Common applications include fire door cores and assemblies, oven and kiln housings, furnace wall liners, welding and torch protection panels, marine fire insulation, electrical enclosures, and aerospace ground support equipment.

AWMCO stocks five Marinite grades sourced from BNZ Materials. All are final, non-restocking inventory — when current stock is sold, it will not be replenished.

Both Marinite and Super Firetemp are available from AWMCO in pre-cut 12"×12" squares across common grades and thicknesses — ready to ship same day on many orders. Squares are a popular format for maintenance teams, labs, OEMs, and field service kits. Typical use cases include hot-face and back-up insulation coupons for ovens, kilns, and furnaces; thermal break pads and equipment spacers; fixture plates and shims for prototypes and test stands.

AWMCO is an authorized distributor for BNZ Materials (Marinite), Johns Manville (Super Firetemp) and Promat (MONOLUX, PROMATECT-MST) — stocking one of the largest selections of high-temperature calcium silicate boards in the U.S. That authorization matters: it means direct pricing, verified product traceability, and access to documentation that general marketplaces like Grainger or Amazon often cannot provide.

Have questions? Feel free to email us at customerservice@awmcousa.com or call (708) 478-6032.