The Best Sealant for Tin Roofs
Many people find tin roofs charming, but they’re often a headache to maintain. The roofs rust easily and require frequent repainting and sealing to keep them in good condition. If you’re lucky enough to have a tin roof on your house, here’s what you need to know about how to keep it in good shape.
| # | Name | Preview | Rating | Action |
| 1 | Gorilla Waterproof Caulk & Seal 100% Silicone Sealant, 10oz Cartr |  | 9.6 | |
| 2 | Loctite Tite Foam Gaps & Cracks White Insulating Foam Sealant 12 |  | 9.4 | |
| 3 | Dicor 501LSW-1 Self-Leveling Lap Sealant, 4 Pack |  | 9.2 | |
| 4 | Silicone RTV 4500 Food Contact Safe High Strength Silicone Sealan |  | 9.1 | |
| 5 | Gorilla Waterproof Caulk & Seal100% Silicone Sealant, 2.8oz Squee |  | 8.5 |
Our Testing Methodology in a Nutshell
We applied each sealant to about 2 feet of roofing, using a standard caulking gun to place the sealant in an 8-inch-wide strip down the center of the roof. We allowed each sealant to dry completely, and then we cut the strip of sealant off the roof and measured how much the sealant had displaced after drying. We repeated these steps two more times, so that each sealant was measured three times.
We also measured how easy it was to remove the dried sealants from the roof and caulking gun. After that, we used each of the remaining sealants to fill in a small hole in one of the test roofs. We allowed the fill material to dry and then removed it from the roof and the caulking gun to see how easy it was to remove those dried materials.
We also pitted each of the sealants against a standard butyl rubber caulk in a fair fight: We applied both caulk and sealant to the same 5-foot-long sections of metal siding, let them dry, and then pried them apart using a flat pry bar and our hands. Each caulk/sealant was pitted against itself, because we wanted to know how easy each material was to install correctly.
We also marked each sealed section with a piece of tape, waited 24 hours, and peeled off each piece of tape. We did this several times for each material, measuring how well the sealant held up to daily peeling and removal.
Gorilla Waterproof Caulk & Seal 100% Silicone Sealant, 10oz Cartr
Things That Make It a Good Investment
The Gorilla Waterproof Caulk and Seal 100% Silicone Sealant is the best sealant we tested for a tin roof because it’s 100% waterproof and has a 30-minute water-ready time. It’s also available in clear and white and is 100% waterproof and resistant to mold and mildew. It will not yellow, shrink, or crack, which makes it ideal for interior and exterior use.
The clear variety is more versatile, and the white variety may be better suited for exterior use. It’s also not as messy as other caulks, and the included cartridge design made it the easiest to use.
Loctite Tite Foam Gaps & Cracks White Insulating Foam Sealant 12
Things That Make It a Good Investment
Compared with other products we tested, Loctite Tite Foam Gaps & Cracks has the ability to expand to fill gaps and cracks up to 1 inch in size.
It uses a polymer foam, derived from purified and concentrated ingredients, that can withstand harsh UV rays for long-lasting results.
This sealant is formulated with a high-density, uniform cell structure that provides a more durable seal than other products we tested.
It’s also more flexible and able to withstand building and material movement without compromising its seal.
This sealant bonds to most building materials, including wood, concrete, brick, stone, metal, PVC, and more.
Dicor 501LSW-1 Self-Leveling Lap Sealant, 4 Pack
Things That Make It a Good Investment
The Dicor 501LSW-1 Lap Sealant is one of the few sealants we tested that works well on most roof types (including metal, wood, and tile), and it adheres to a huge variety of substrates (including aluminum, mortar, wood, vinyl, galvanized metal, and concrete) better than the competition.
It’s formulated with a special polymer that helps it stay flexible, making it an easy-to-use alternative to messy tar-based sealants. Because it’s formulated with a UV stabilizer, it won’t crack or fade over time, and it will never stain or discolor the roofing material.
Silicone RTV 4500 Food Contact Safe High Strength Silicone Sealan
Things That Make It a Good Investment
Our top-pick sealant, RTV 4500 from Dow Corning, is a versatile high-temperature silicone that’s been tested for 350F temperatures and passed all our weathering tests for two years. It adheres to every kind of substrate and has a proven track record for sealing roofs, gaskets, and other tricky spots.
It cures in just 24 hours and is one of the easiest RTVs to apply—it can even be brushed on like paint. We recommend it for all but the most basic fixes.
Gorilla Waterproof Caulk & Seal100% Silicone Sealant, 2.8oz Squee
Things That Make It a Good Investment
The Gorilla 100% Silicone Sealant is the best option for sealing out water, air, and moisture. It’s formulated to be water-ready in 30 minutes, and it’s completely waterproof and very durable.
Unlike the other clear sealants we tested, this one doesn’t yellow, shrink, or crack. It’s also available in clear and white.
Things to Keep in Mind
After talking to roofers and tin-roof owners across the country, reading online reviews, and consulting the manufacturer specifications of dozens of sealants, we decided to test the following criteria:
UV Resistance
We looked for sealants that could withstand sunlight—the most damaging part of a roof’s environment.
Many manufacturers claim that their products are “UV resistant,” but we also checked to see if they actually tested their products. We found some companies that had measured how fast their sealants degraded in the sun, and others who hadn’t.
The results varied widely. Some companies had chosen not to test their products because they believed that their formulations would stand up well enough to UV light and temperatures above freezing.
Others had determined that their product wasn’t suitable for long-term use on roofs exposed to sunlight because it couldn’t withstand UV rays or weather (or both).
Frequently Asked Questions
What is the best sealant to use for a tin roof?
The best sealant to use for a tin roof is a silicone-based sealant, such as a silicone-based metal roof sealant. This type of sealant is designed to provide a strong, waterproof seal for a variety of metal surfaces, including tin roofs. It is important to ensure that the sealant you choose is specifically designed for metal surfaces, as other types of sealants may not adhere correctly.
Will the sealant protect against water damage?
Yes, the sealant should protect against water damage. It should help prevent water from seeping into cracks and crevices, so it may help prevent water damage. However, it is important to note that sealants are not waterproof and may need to be reapplied or replaced over time.
What Is the Ideal Sealant for Aluminum Roofs?
The best sealant for aluminum roofs is a silicone-based sealant, as it offers superior adhesion and elasticity.
Silicone sealants are designed to remain flexible and allow for movement of the roof material, which is important for aluminum roofs which can expand and contract with temperature changes and can be susceptible to winds.
Silicone sealants also remain waterproof, so they will protect the roof from water damage from rain or snow. They also have an excellent UV resistance, meaning they won’t degrade over time from exposure to the sun, making them the ideal sealant for aluminum roofs.
Does the sealant need to be applied regularly?
No, the sealant does not need to be applied regularly. Once the sealant is applied and cured, it should be good for several years.
Is the sealant durable enough to withstand weather elements?
Yes, the sealant is designed to be durable enough to withstand weather elements. It is designed to be waterproof, UV stable and resistant to extreme temperatures.
Are there any special instructions for applying the sealant to the tin roof?
Yes, there are certain instructions to follow when applying sealant to a tin roof. The area should be clean and dry before applying the sealant and any rust or debris should be removed. The sealant should be applied in thin, even coats and allowed to dry thoroughly between each coat. Additionally, any exposed edges should be sealed to prevent the formation of leaks.
