Can You Repair A Broken Slate Roofing Tile?

Posted on: 5 November 2017


If you have a slate roof, then you can expect that your roofing materials will last close to 100 years and sometimes up to 150 years. This is obviously a long time when it comes to roofing materials, and you are likely to see the slate changing colors as it ages. When slate ages, it does start to become brittle and many people wonder if cracks can be repaired in the slate. Keep reading to learn if you can: 

Can Slate Cracks Be Repaired?

Since slate is a hard and brittle material, it is impossible to truly repair a piece of slate. Slate is a large piece of metamorphic rock that is composed of clay and/or volcanic ash. The rock material is formed in sheets and compressed to create the slate. Unfortunately, once the sheets of the rock are broken, they will remain that way and likely deteriorate further. While this is true, you can fill and seal the crack as long as you use a flexible material that can bend slightly as the weather changes.

The best material to use is a masonry repair compound. This material is meant for fixing breaks and cracks in brick and stone. The repair compounds are typically made for both indoor and outdoor use and cure quickly.

Masonry repair materials come in gray, black, white, and sometimes clear colors, so choose the option that best matches the slate. Spread the compound in the crack and also gently spread the material a small amount over the matched edges of the slate. This will help to prevent deterioration and leak issues. 

If you do not want to use a masonry compound, then you can opt for an epoxy repair material. Epoxies are often made for larger cracks and repair areas. Also, keep in mind that the epoxy is not nearly as flexible as general masonry repair materials and that it will crack over time. 

Should A Replacement Be Completed?

Since repairs merely patch the slate and do not fix it, you may want to consider replacing the cracked piece of slate instead. This is ideal if you want to retain the beautiful appearance of your roof. To replace the slate, you will need to locate a matching piece of slate. Work with a roofing professional to help you determine whether you have hard or soft slate and to also figure out where the slate was initially mined. The mining region greatly influences the color of the shale and will help you match the tone.

In many cases, suppliers will have aged shale that is available so the repair will match as closely as possible. Keep in mind that it may be a bit time-consuming and expensive to locate a matching piece of roofing material. For this reason, it may be wise to invest in a full replacement if there are many pieces of slate that need to be replaced. 

Contact local roofers for more information and assistance.