Metal Roof Sealants Here: Comprehensive Guide & Advice!

Metal roofing is notorious for rust, cracks between seams, holes where nails or screws were used to affix them, and wind damage.

There are a number of solutions to remedy a damaged metal roof, among the best-known repair solutions, are metal roof screw sealant. These metal roof repair sealant kits are numerous and easy to find, buy and apply.

Here is the list of the 5 best products, and this review article closes with an FAQ and roof repair 101.

METAL ROOF REPAIR – TARGETED USE OF SEALANTS

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List of Top-Rated Metal Roof Sealants

PhotoNameColorUnitDescription
1. Sashco Through the Roof Cement & Patching SealantSashco 14010 Metal Roof SealantTransparentCartridgeView on Amazon
2. Novaflex Metal Roof SealantNovaflex Metal Roof SealantManyCartridgeView on Amazon
3. Tuff-Guard Heat-Block White Reflective Roof CoatingTuff-Guard Heat-Block Metal Roof SealantWhiteGallonView on Amazon
4. Tuff-Guard Advantage 1 roof sealantTuff-Guard ADV1-1GAL Metal Roof SealantWhiteGallonView on Amazon
5. Titebond Weathermaster metal roof sealantTitebond 61781 Metal Roof SealantManyCartridgeView on Amazon

The Best Metal Roof Sealants Reviews

1. Sashco Through the Roof Cement & Patching Metal Roof Sealant

Through the Roof!® is a clear, waterproof, ultra-elastic sealant. This product is best used to stop and prevent leaks, it is waterproof, and since its clear, you can use it over finished surfaces without damaging the design features of color.

Features

Through the Roof!® can be applied in temperatures down to 0°F and sticks to wet surfaces so you can apply this in all weather condition. It is also UV resistant, so it will work well in hot sunny climates as well as cold ones, and where there are extreme temperature changes, this product is superelastic and doesn’t dry and crack.

Specification

  • Color: Clear
  • Packaging: 10.5 oz. plastic cartridge, 1 quart and 1 gallon containers
  • Joint Size: Cartridge – up to 2” wide; Brush grade – N/A
  • Paint Usage: latex paint: stain in 24 hours; oil-based paint stain after 1 week
  • Clarity (NTU): Cartridge grade – < 13; Brush grade - < 15
  • Application Range: 0°F to 120°F (-18°C to 49°C) surface temperature
  • Service Range: -25°F to 180°F (-34°C to 82°C)
  • Tensile Properties: Cartridge – Recovery; at 50% stretch: 96% in 1 minute; at 100% stretch: 96% in 1 minute; Brush – Recovery; at 50% stretch: 100% in 3 minutes; at 100% stretch: 96% in 5 minutes

2. Novaflex Metal Roof Sealant

NovaFlex® Metal Roof Sealant comes in a variety of colors including transparent, so you can apply this to any and every application without affecting the overall beauty of your original design.

Features

The NovaFlex® Metal Roof Sealant is applicable in all weather conditions and withstands extreme temperature variances ranging from -40ºF to +400ºF. When you apply this product, you can work in a temperature range between -20ºF to +120ºF.

The product dries within 10 minutes but is fully cured after 2 days and will also adhere to Kynar® coated metals. This is mildew resistant and freezes stable thaw material when fully cured.

Specifications

  • Service temperature: -40ºF to +400ºF
  • Application

    temperature: -20ºF to +120ºF

  • Tack free time: 10 minutes
  • Completely cured: 2 days
  • Adheres to: Kynar® coated metals
  • Meets CARB and OTC regulations (VOC Compliant)
  • Meets or exceeds ASTM C-920-00, TT-S-001543A and TT-S-230C

3. Tuff-Guard Heat-Block White Reflective Metal Roof Sealant

Tuff-Gard Heat Block Reflective Coating is a rubberized brilliant white reflective coating that is best used as a waterproofing sun protectant in hotter climates.

Features

Tuff-Gard Heat Block Reflective Coating is a full coating product used to both rubberize the roof surface as well as provide a brilliant white reflective coating to reflect harsh sunlight. This product, when applied over the roof surface provides you with over 88% Solar Reflectance and over 90% Thermal Emittance.

Specifications

  • Qualification for LEEDS applications
  • Rubberized Components to Increase Elasticity
  • Anti-Mildew agents to Prevent Mildew Growth
  • Anti-Bacterial agents to Prevent Bacteria build up

4. Tuff-Guard Advantage 1 Metal Roof Sealant

Tuff-Gard Advantage 1 is a single component Rubberized, Solvent-free and waterproof coating for your roof.

Features

Tuff-Gard Advantage 1 is 100% Waterproof. This is an all surface coating product that is perfect for anything from a small crack fill job to a total coating application:

  • Can be brush applied
  • For larger applications use a roller or squeegee
  • Can be applied to moist areas
  • Not intended for use as a walking surface
  • Adheres well to all types of foam, concrete, stone, wood, cement, metal and EPDM
  • Eco-Friendly and Minimal odor

Specifications

  • Elongation: >1800%
  • Low Temperature elongation: @ 22F >500%
  • High Temperature Aging for 48 days @ 176F: Elongation >300% min.
  • Service Temperature: -35F to 176F
  • Water Absorption Weight change 1.02% maximum
  • Water Vapour Transmission 0.08 grains /hr/ft
  • Permeance 0.16 grains/hr/ft/in Hg (perms)
  • Resistance to Hydrostatic Head >150 ft water
  • Class A Fire Rating

5. Titebond Weathermaster Metal Roof Sealant

Titebond® WeatherMaster™ Metal Roof Sealant is a polymer formula that provides waterproof and dustproof seal solutions for all roof products.

Features

The WeatherMaster adheres to Kynar™ coated metal materials, and all standard metal, aluminum, steel, galvanized bonderized surfaces, plastics and glass.

This sealant comes in 50 different colors so you can match your seal to any design, it also comes with a transparent variant.

The Weathermaster is applicable in extreme weather conditions, with temperatures as low as 0°F/-18°C. The UV resistant properties make this a perfect choice for sunny climates too.

You can paint over this product using a water-based (latex-based) paint one hour after application.

Features

  • Adheres to Kynar™ coated metals
  • Applies easily in extreme weather conditions
  • Excellent adhesion to most common building materials
  • Permanently flexible, weather-tight seal
  • UV-resistant
  • VOC-compliant
  • Compatible with all types of foam

How to fix a metal roof

Metal roofing comes with a number of issues, and these include:

  • Open seams
  • Open penetration flashings
  • Metal roof oxidation
  • Fastener backout
  • Open ridge/headwall flashing
  • Loose counterflashing
  • Improper installation methods
  • Panel damage

There are a number of options to choose from when dealing with roof problems, and these include repairing, restoring and replacing the roof materials.

Metal Roof Repair and Replacement Options: Repair versus Restoration versus Replacement

Repairing a roof requires ongoing maintenance, and when you maintain a metal roof, it will last for up to 30 years or more. You should look at the status of the roof every half a year and fix any problems before they become extreme.

The most common issues include open seams and oxidation, both of which are easily repaired.

Restoration is when you make a comprehensive repair of all the roof, which means cleaning all the roof surface and seams, applying rust inhibitors, undercoats and top coats. You might consider adding a sun or waterproofing sealant.

Replacement is usually performed when repair and restoration are costlier than replacing the metal sheets. You simply buy a new sheeting and replace the old ones with the new ones.

How to fix a leaking tin roof

Corrugated metal roofs do get damaged from excessive moisture and strong winds. The two key components that tend to get affected first are the seams and the steel nails or screws used to attach the roofing sheets.

First, locate the problem, and then ascertain what needs to be done. Will a simple repair job suffice, or do you need to restore the whole section? Perhaps you need to replace the sheet with a new one. Let’s look at the basic leak fix job, where either a seam has parted, or a nail has rusted.

Remove all the nails that are rusted and check the sheet for roof corrosion damage. Scrape off all rust from the hole area and coat the damaged area with a rust inhibitor. Let that dry and then coat it with paint and let that dry too. Now hammer in a new nail and then cover it with a sealant.

Check the damaged seams for corrosion, if there is rust, perform the same preparatory action as above, if not, go to the next step in the process. Remove all the loose caulking and adhesives and clean the area. Apply a roof sealant to the seam and close it up.

Another area to check is the roof panel edges where they overlap, check for gaps and cover the overlapping areas with fabric tape, you can smear a sealant onto the area and then cover with the fabric. After an initial dry time, cover it with a waterproofing, or weatherproofing coating.

How to waterproof a metal roof

  • Make sure all the roof surface is dry.
  • If there is rust brush it and remove it completely.
  • Apply metal primer over all the roofing.
  • When the primer has dried apply a coat of waterproofing compound along with the sheet overlaps, metal screws and nail heads and all flashings. You can also use strips of fabric along seams and coat them again with a sealant after the first layer has dried.
  • After completing these stages, you can coat the entire roof with a coating of sealant and over that an all-weather paint.

How to paint a steel roof

Painting directly onto galvanized steel is not recommended. It’s always best to put on a layer of primer first. After the primer has dried, apply an all-weather sealant.

Once all the pre-paint stages have fully cured, you can now apply a coat of paint. There are three methods, and they are all reliant on the type of roofing you took.

Brush, roller and spray work well, each one is used for a different shape of the material, where brush and spray work well with all surfaces, rollers only work well on flat surfaces.

  • Remove the old paint and rust before starting any roof paint job.
  • Make sure that the paint you choose is an all-weather paint designed to paint over polymer surfaces or primer paint.
  • Always use a sturdy ladder and work as a team of two, where one is up to the ladder painting, the second is preparing the paint and watching the ladder’s stability.
  • Always wear a harness when painting from a ladder.
  • Only paint on dry days, and make sure the weather will remain dry for at least 3-4 days during and after the paint job.
  • When applying primer and paint, make the strokes equal and in the same direction. Do not apply too thin a coating, be generous with your application.
  • Check the complete drying time before applying a second coat; this means its best to wait at least one day between applying coats.

What paint to use on metal roof

Two types of paint to apply to all metal roofs, these are primers and paints.

Primer
There is no one solution for all, a primer is a special material and is not a paint. It is a substance that adheres to the surface of the metal and bonds on a molecular level. Paint is a surface coating that does not bond to metal and will peel without a coating of primer. The primer also bonds on the molecular level with paint. Essentially the primer is the center of a sandwich between metal and paint.

Paint
For roof applications, oil-based paint is the only option you want to choose. These are waterproof paints that will leave a smoother shinier surface than latex paints. There are also a number of brands that have developed “roof paint” designed specifically to withstand the harsh weather conditions and strong UV and IR rays of the sun. They also have a higher resistance to heat and cold changes.

About the author

Jessica Nickson

Jessica Nickson

Jessica Nickson is a keen home and garden innovator with over 25 years of hands-on experience in, home improvement, landscape gardening and all things appliance related to making life easier and more interesting. You can contact her via e-mail - jessica@thehomedweller.com.

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