How to Identify and Use the Current NovaFlex Sealant for Metal Roofing

Short answer: what NovaFlex metal roof sealant is now called

Novagard says NovaFlex Metal Roof & Panel Adhesive Sealant has been rebranded as NovaFlex Pro Premium Adhesive Sealant. The legacy cartridge product is described as a single-component, non-corrosive, oxime-cured silicone used primarily to seal seams and fill joints in metal-roof and panel systems. Novagard also says former colors moved to the Pro Premium line. See Novagard’s product and rebrand notice.

That establishes the replacement name, but it does not prove that every old cartridge, color, stock number, retailer-specific SKU, and current NovaFlex Pro product is chemically identical. Treat “rebranded” as a product-line identity statement—not permission to transfer every legacy specification to every similarly named tube.

This distinction is especially important because the principal manufacturer page available for comparison describes the legacy Metal Roof & Panel product and announces the rebrand. Before relying on any specification for a delivered NovaFlex Pro Premium cartridge, compare it with the current technical data sheet tied to that exact SKU.

Before ordering, check:

• Current product name
• Manufacturer and exact SKU
• Color name and NovaFlex color code
• Cartridge volume
• Chemistry and cure type
• Technical data sheet (TDS) revision
• Safety data sheet (SDS)
• Intended substrate and application
• Lot or date information, where shown
• Roof-panel, coating, and accessory requirements

Retailers continue to use a mixture of names and identifiers, including MR150, M150, NFMR-series SKUs, “Clear Silicone Metal Roof Sealant,” and “Metal Roof Adhesive Sealant.” Those identifiers can help locate a listing, but the available evidence does not establish that they are universally interchangeable with one another or with every NovaFlex Pro Premium color.

The words adhesive sealant also require care. They describe a material that can seal and bond to suitable surfaces, but they do not establish approval for structural attachment.

Product identity guide: cartridge sealant, clear MR150 listings, and patch mastic

The safest way to identify a NovaFlex product is to start with its package and application method. Do that before comparing cure times, coverage, price, or installation instructions.

Retail examples illustrate the naming problem. One listing identifies a clear 10-ounce cartridge as EF-NOVAFLEX-M150, while another retail channel uses NOVAFLEX-M150. These listings show how M150 is used in commerce, but they do not demonstrate universal equivalence among M150, MR150, NFMR color codes, and every NovaFlex Pro cartridge. Review an example M150 cartridge listing.

The patch mastic is physically easier to distinguish. Novagard’s store describes NovaFlex Metal Roof Repair & Patch Mastic as a translucent silicone sold by the gallon and applied with a brush or trowel. The page uses MRR150 in the title and MRR1500-01G as the SKU. It also gives a one-hour rain-safe value at 70°F and 50% relative humidity. Review the separate patch-mastic listing.

Do not transfer that mastic’s one-hour rain-safe value, gallon packaging, brush-or-trowel application method, or broad-area repair assumptions to a NovaFlex cartridge. Conversely, cartridge skin time does not establish how a thick mastic repair should be designed or applied.

Correct identification controls almost every later decision:

• Cure: Formulations, bead thicknesses, and repair builds can cure at different rates.
• Coverage: A cartridge bead and a troweled patch use material in fundamentally different ways.
• Application: A caulked joint depends on bead placement and tooling; mastic may require a controlled film or high-build application.
• Color: Clear, translucent, and factory-matched colors are not aesthetically interchangeable.
• Weather exposure: Rain-safe claims must belong to the exact product and stated test conditions.
• Warranty: Roof or product warranties may depend on the approved material and detail.
• Attachment: Weather sealing does not automatically provide a required structural connection.

If an online title conflicts with the physical label or current TDS, use the manufacturer documents tied to the delivered product—not the retailer’s abbreviated title.

NovaFlex specifications: chemistry, temperatures, cure time, and ASTM classification

The following table reports data published for the legacy NovaFlex Metal Roof & Panel Adhesive Sealant associated with the rebrand. It should not be treated as a substitute for the current NovaFlex Pro Premium TDS for the exact SKU in hand.

Source for the legacy-product specifications and regulatory statements: Novagard’s manufacturer product page.

Skin-over, tack-free, rain exposure, and full cure are not the same

Skin-over means a surface film has begun forming. Tack-free means the exposed surface no longer feels tacky under the applicable test or description. Neither milestone necessarily means that the bead is cured through, ready for design movement, or safe from uncontrolled rain.

Cure-through refers to cure through a specified material thickness under stated conditions. A surface can appear cured while material deeper in the bead remains uncured.

A specialty metal-roof supplier publishes these condition-specific skin times:

• Approximately 40 minutes at 40°F and 40% relative humidity
• Approximately 10 minutes at 75°F and 50% relative humidity
• Approximately 5 minutes at 95°F and 95% relative humidity
• Approximately 48 hours for cure-through at 75°F and 50% relative humidity

These examples show why “ten-minute cure” is inaccurate. Ten minutes is a surface-working milestone under moderate conditions, not full cure. See the condition-specific timing table.

Do not promise that every bead will cure completely in exactly 48 hours.

Retail information is not consistent. One NovaFlex Pro Premium listing gives an application range of -20°F to 120°F in one place and 0°F to 120°F elsewhere, while separately stating that the product extrudes at -20°F. The same page mentions both a 12–24-hour complete cure and a period of up to two days. These conflicts are a reason to use the current manufacturer TDS rather than averaging retail figures. Review the conflicting retailer specifications.

What the ASTM labels mean—and do not mean

For ASTM C920 terminology:

If movement capability is important to the repair design, obtain the current TDS and manufacturer joint-design instructions. Do not design the joint from the class number alone.

Where NovaFlex can—and cannot—be used on a metal roof

NovaFlex cartridge silicone is principally a weather-sealing material. Its appropriate role is generally a localized joint or penetration where the substrate is sound, the product is compatible, and the roof detail does not need reconstruction.

Manufacturer-listed applications include:

• Metal-roof and wall-panel seams and joints
• Rivets and screw heads
• Corner joints and trim transitions
• Localized flashing joints and edges
• Properly assembled pipe boots and other penetrations
• Gutters and downspouts
• Trim and termination bars
• Mechanically fastened snow guards

A surface bead can block a suitable water path, but it cannot re-create a failed roof assembly. If a seam opened because clips, fasteners, panels, or framing moved, the cause must be corrected. Sealant over displaced or badly formed flashing may conceal a gap without restoring the necessary drainage path, overlap, or mechanical connection.

Snow guards require attachment, not just sealant

A specialty snow-guard seller recommends MR150 for sealing mechanically fastened snow guards on exposed-fastener roofs and repeatedly states that the product is not intended to glue snow guards to the roof. Read the MR150 attachment limitation.

Apply that principle to other load-bearing accessories. Sealant can weather-seal approved penetrations, but the component still needs the attachment specified by its manufacturer or the project design. Snow and ice loads, wind, thermal movement, and panel geometry cannot be reduced to the cartridge’s adhesion description.

Paint and water limitations

Specialty supplier and contractor documentation reports that the cured silicone is not paintable and is not recommended for joints that remain submerged. Choose the appropriate color before application and select another material specifically approved for continuous immersion when that is the expected exposure. Review the reported paint and submersion limitations.

A separate retailer says MR150 can cure in wet conditions or underwater. Even if a sealant can continue curing after water exposure, that is not equivalent to approval for permanent submerged service. Curing behavior and long-term service suitability are different questions. Given the conflict, do not interpret the underwater-curing statement as authorization for a continuously submerged joint.

Professional assessment is prudent when:

• A leak returns after previous sealing
• A standing seam is separated or distorted
• Flashing is displaced, incorrectly lapped, or extensively failed
• Corrosion is widespread or the panel is perforated
• Several seams or penetrations are failing
• The work could affect a roof, panel, coating, or workmanship warranty
• Safe access or reliable leak tracing is beyond the worker’s capability

Substrate compatibility: Kynar, galvanized steel, aluminum, PVC, masonry, and more

A compatibility list is a screening tool—not final approval for a particular roof.

The distinction is especially important for factory-coated metal.

Seller guidance describes MR150 as suitable for Kynar-coated, Galvalume, and galvanized roofs, but this is not universal approval for every panel, coating, or assembly. It should be checked against the delivered sealant’s documentation and the panel manufacturer’s requirements. See the seller’s substrate statements.

Before committing to a visible repair:

1. Identify the panel metal and exact factory finish, if known.
2. Review the panel or coating manufacturer’s sealant and warranty requirements.
3. Review the current NovaFlex TDS for the exact cartridge.
4. Determine whether the surface condition calls for primer or special preparation.
5. Make a small adhesion test in an inconspicuous location.
6. Allow the test to cure under representative conditions before evaluating it.

Do not convert a retailer’s “primerless adhesion” statement into a universal no-primer rule. Porous masonry, aged plastic, weathered coatings, oxidized metal, and unusual finishes may require different preparation or direct manufacturer guidance.

Surface condition can matter as much as the underlying material. Oil, dirt, moisture, corrosion products, loose paint, chalked coating, oxidation, and failed sealant can leave the new bead bonded to contamination rather than to the roof.

Remove loose or incompatible material and test the prepared surface rather than assuming that fresh silicone will bond to an old bead.

Application checklist: preparation, bead placement, tooling, and curing

This is a general workmanship and decision checklist. The current product-specific TDS, SDS, roof-manufacturer instructions, accessory requirements, and applicable safety procedures take priority.

1. Diagnose the leak before opening the cartridge

Confirm that the visible location is the actual entry point and that the defect is suitable for sealing. Look for:

• Loose, backed-out, missing, or incorrect fasteners
• Separated or distorted seams
• Corroded or perforated panels
• Split boots or failed penetration assemblies
• Displaced, short, or incorrectly lapped flashing
• Water traveling beneath panels from an uphill defect
• Condensation rather than rain leakage
• Failed concealed sealant or closure components

Replacing an approved fastener, mechanically re-closing a seam, rebuilding flashing, or replacing a damaged boot may be necessary before sealant can contribute to the repair.

2. Verify the product

Read the cartridge rather than relying only on the online order title. Confirm:

• NovaFlex product name
• SKU and color code
• Package size
• Chemistry
• Lot or date information, if provided
• TDS and SDS revision
• Substrate and application suitability
• Temperature and weather limits
• Primer or joint-design requirements

Do not use MRR150 patch-mastic instructions for a cartridge product.

3. Make roof access safe

Do not treat a minor sealant repair as justification for uncontrolled fall exposure. As a general precaution, avoid working on steep, wet, icy, damaged, fragile, or difficult-to-access roofs. A roofing contractor’s seam-repair guidance recommends professional service for standing-seam work, extensive failure, difficult flashing, steep roofs, and warranty-sensitive projects. Review those professional-repair boundaries.

Use a qualified roofer when safe access, fall protection, leak tracing, or repair complexity exceeds the worker’s equipment and competence.

4. Prepare a sound surface

Remove loose or failed sealant, rust scale, dirt, oil, oxidation, peeling coating, and other contamination without gouging the panel or damaging its protective finish. The remaining substrate must be stable enough to support the new bead.

Use cleaning methods accepted by the roof and coating manufacturer. Do not assume that an aggressive solvent or abrasive is safe for a factory finish.

Allow the area to become clean and dry. Although a retail listing mentions curing under wet conditions, the available evidence does not supply sufficiently authoritative wet-surface instructions for every NovaFlex cartridge, substrate, and roof assembly.

5. Check compatibility and primer needs

Pay particular attention to:

• Factory-coated metal
• Galvanized or Galvalume surfaces
• Weathered metal
• Masonry
• PVC or membrane materials
• Previously sealed joints
• Unidentified paint or coating

If the documentation is unclear, consult the sealant and roof manufacturers and perform a small adhesion test. Do not apply the full repair first and use the next storm as the test.

6. Dry-fit and mechanically correct the assembly

Replace defective fasteners with the approved type and size. Restore loose accessories to their specified attachment and correct flashing position where practical.

Do not use sealant to hold a moving component in place while omitting required fasteners or attachment hardware.

7. Apply a continuous, appropriately sized bead

Cut the nozzle to suit the joint and apply an uninterrupted bead that contacts sound material on both sides. Avoid voids, thin skips, and decorative surface smears that do not engage the joint edges.

The available documentation does not establish one universal bead width, depth, or maximum gap for every NovaFlex roof application. Joint geometry should come from the current TDS, roof detail, and project-specific instructions.

8. Tool promptly

Tool the bead while it remains workable, pressing it into contact with the joint faces and shaping it to shed rather than trap water.

Contractor guidance based on the product data describes tooling within roughly 5–10 minutes under typical conditions, while also reporting an approximate 48-hour full-cure period. Both values are conditional and should be checked against the current cartridge documentation. See the reported application and cure guidance.

Apply only as much material as can be placed and tooled within the available working time.

9. Protect the repair during cure

Keep the joint from being disturbed, stretched, contaminated, or washed before it reaches the appropriate cure milestone. Skin-over or tack-free time is not full cure.

Cold, low humidity, bead size, depth, and joint geometry can extend the cure schedule. If rain is imminent and the current cartridge documentation does not provide an applicable exposure time, postpone the repair or obtain product-specific guidance.

Do not apply the patch mastic’s one-hour rain-safe value to a NovaFlex cartridge. The mastic figure applies to a different gallon-format product at 70°F and 50% relative humidity.

10. Inspect after cure and after the next weather event

Check for:

• Edge lift or adhesion loss
• Voids, pinholes, or skipped areas
• Uncured material
• A bead shape that traps water
• Continued fastener or seam movement
• Leakage from an uphill or concealed source

If the leak returns, stop stacking new beads over the previous repair. Recurrence can indicate a diagnosis, compatibility, preparation, movement, or assembly problem.

NovaFlex versus butyl tape, polyurethane, and silicone patch mastic

The right material depends on where it sits and what it must do. Chemistry alone does not determine success.

When NovaFlex makes sense

A NovaFlex Pro cartridge is a plausible option when:

• The job is a localized exposed weather seal
• The surface is sound and compatible
• The joint movement is within the designed detail
• The area can be properly cleaned and prepared
• The bead can be placed and tooled correctly
• Structural attachment is not being delegated to the sealant

Examples can include sealing around an approved screw penetration, a sound flashing edge, a properly installed pipe boot, or a mechanically secured accessory.

When butyl tape makes more sense

Butyl tape may be preferable inside a concealed panel overlap because it is compressed between components and protected from direct sunlight. It is often part of the original assembly detail rather than a later exposed repair.

Access may require lifting or disassembling components, so butyl is not automatically a simple retrofit. The roof manufacturer’s lap and closure details should control.

When polyurethane may be considered

Polyurethane is another exposed-repair category, and some products are marketed as paintable. The supplied guidance is not consistent, however: one manufacturer recommends its polyurethane roof-and-flashing product for small metal-roof leaks, while a roofing contractor broadly cautions against polyurethane on metal without primer.

Neither position supplies universal comparative testing across all polyurethane formulations, primers, metals, and factory coatings. The practical answer is product-specific: compare the exact polyurethane TDS with the exact metal finish and joint. Review one manufacturer’s polyurethane repair guidance.

Do not assume that every polyurethane is paintable or that every silicone is suitable merely from the chemistry category.

When patch mastic or reconstruction is needed

MRR150 patch mastic may suit a broader or irregular repair area that calls for brush or trowel application. It still requires its own preparation, thickness, weather, and cure instructions.

Significant standing-seam openings, displaced flashing, extensive corrosion, panel perforation, and recurring leaks are different problems. They may require mechanical seam re-closing, a designed matching-metal patch, flashing replacement, or panel replacement.

Adding more sealant can obstruct diagnosis and make later repairs harder. No supplied independent comparative testing proves that NovaFlex is universally the best metal-roof sealant, and the evidence does not establish a specific service life. Selection should depend on joint location, substrate, coating, movement, exposure, paintability, repair access, and roof-manufacturer requirements.

Buying checklist: color codes, cartridge sizes, documents, and changing retailer data

Record the job requirements before ordering, then compare them with the physical product delivered.

Pre-purchase checklist

• [ ] Current product name
• [ ] Exact manufacturer SKU
• [ ] Cartridge sealant versus patch mastic
• [ ] Required chemistry and cure type
• [ ] Cartridge or bulk-package volume
• [ ] NovaFlex color code
• [ ] Roof metal and exact factory coating
• [ ] Existing sealant chemistry, if known
• [ ] Intended seam, joint, flashing, or penetration
• [ ] Required mechanical attachment
• [ ] Forecast temperature, humidity, and rain exposure
• [ ] Current TDS revision
• [ ] Current SDS
• [ ] Primer and joint-design requirements
• [ ] Roof, panel, coating, and workmanship warranty requirements
• [ ] Quantity based on actual bead dimensions and expected waste

A common retail format is approximately 10 or 10.3 fluid ounces. For example, one NovaFlex Pro color listing identifies a 10.3-fluid-ounce cartridge and an NFMR-series color SKU, while legacy clear listings may show 10 ounces. Package labeling should control. See an example 10.3-fluid-ounce NovaFlex Pro listing.

A specialty supplier also lists 20-ounce sausage packs, 5-gallon pails, and 55-gallon drums. Verify current availability and confirm that the bulk package has the formulation, type, and color required before substituting it for a cartridge. Review the listed package formats.

Color requires a code, not a screen guess

The legacy product was offered in numerous color matches, and Novagard says former colors moved to NovaFlex Pro Premium. Current availability can still change.

Order by the NovaFlex color code where possible. Generic descriptions such as “sandstone,” “bronze,” “gray,” or “white” can refer to different finishes among panel manufacturers.

For a visible repair, compare a physical cured sample with the actual panel.

Because the cured silicone is reported as unpaintable, a color error may require removal and reapplication rather than correction with a topcoat.

Do not rely on a generic coverage number

Linear-foot coverage depends on the bead’s cross-sectional area. A thin bead around fasteners and a deep joint consume radically different amounts of material.

The supplied evidence does not establish a dependable product-specific coverage table for common bead widths and depths. Measure or estimate the actual joint geometry, include tooling and waste, and use package-specific coverage information if the manufacturer supplies it for the exact product.

Separate stable specifications from temporary retail data

Prices, stock counts, quantity discounts, ratings, review totals, shipping dates, and displayed color selections can change at any time. They are shopping information, not stable product specifications.

Save the order-page description if it matters, but verify the delivered label before use. For unresolved questions—especially primer, joint dimensions, cleanup, personal protection, rain exposure, and any Proposition 65 warning—consult the current TDS and SDS associated with the exact SKU. A warning icon alone does not identify the relevant substance or precautions.

Frequently asked questions

Is NovaFlex Metal Roof Sealant the same as NovaFlex Pro Premium Adhesive Sealant?

Novagard says NovaFlex Metal Roof & Panel Adhesive Sealant was rebranded as NovaFlex Pro Premium Adhesive Sealant. That makes Pro Premium the current product name to investigate when replacing the legacy cartridge.

The rebrand notice does not establish that every legacy SKU, MR150 or M150 retailer listing, NFMR color, and current package is chemically identical. Compare the physical label, exact SKU, color code, current TDS, and current SDS before treating an old specification as current.

How long does NovaFlex metal roof sealant take to cure, and when can it get wet?

Retail and legacy product information commonly reports a short surface-working period and approximately 48 hours for full or through cure under specified conditions. One current color listing, for example, gives a 10-minute tack-free time and 48-hour full cure. Actual timing can change with temperature, humidity, bead dimensions, and joint geometry. See the cited cartridge timing.

Skin-over or tack-free time is not the same as rain-ready or fully cured. The supplied evidence does not establish one universal rain-ready time for every cartridge.

The one-hour rain-safe value belongs to the separate MRR150/MRR1500 gallon-format patch mastic at 70°F and 50% relative humidity—not to the NovaFlex cartridge. Follow the current cartridge TDS for rain-exposure instructions. See the mastic’s condition-specific rain-safe value.

Will NovaFlex adhere to Kynar-coated, galvanized, or Galvalume metal roofing?

Novagard lists Kynar-coated metal among compatible materials. Seller listings also describe compatibility with galvanized steel and Galvalume. Those listings are useful for initial screening, but they do not approve every coating formulation, weathered surface, or roof assembly.

Confirm the exact panel finish, warranty requirements, preparation method, and primer guidance. Then perform a small adhesion test in an inconspicuous area before completing the repair.

Can NovaFlex be used to glue snow guards to a metal roof?

Do not assume so. Available MR150 seller guidance describes it as a sealant for mechanically fastened snow guards, not a stand-alone adhesive for gluing snow guards to the roof.

Use the snow-guard manufacturer’s approved mechanical or engineered attachment system. Sealant may weather-seal penetrations around that attachment, but it must not replace it.

Can cured NovaFlex silicone be painted or used in a submerged joint?

Supplier and contractor documentation reports that the cured cartridge silicone is not paintable and is not recommended for joints that remain submerged. Choose the correct color before application and use a product explicitly approved for continuous immersion when that is the expected exposure.

A statement that a sealant can cure after water exposure does not establish suitability for permanent submerged service. Cure conditions and long-term service approval are separate questions.

Bottom line: NovaFlex Pro Premium is a plausible current choice for localized metal-roof weather sealing when the exact cartridge is compatible with a sound substrate and the joint does not require structural attachment, submerged service, or mechanical reconstruction. Before buying or applying it, verify the current label, TDS, SDS, color code, roof-manufacturer requirements, weather conditions, and attachment method. Recurring leaks, separated seams, damaged flashing, extensive corrosion, and unsafe access call for professional assessment rather than another bead of sealant.