If you notice that the slate tiles on your roof have a pitted and chalky appearance, they may be delaminating. A slate tile will start to delaminate when the calcium that's naturally present in slate begins to oxidize. The presence of the oxidized calcium in the tile makes it weaker and more likely to break apart, which can cause your home's roof to leak. If you think that your slate roof is starting to delaminate, read on to learn more about what causes it to happen and how you can fix it.
What Causes Slate Tile to Delaminate?
Slate tile is made from natural stone that's quarried from the ground and cut into a rectangular tile shape. Since it's natural stone, a slate tile will contain impurities like calcium. Low-quality slate tile has more of these impurities. Your slate tile roof is constantly exposed to the air, so the oxygen in the air can oxidize the calcium in the slate and turn it into calcium oxide.
When the calcium oxidizes, it increases in size, and the pressure of the expanding calcium will place stress on the surrounding slate. This pressure will cause small flakes of slate to break off from the tile, which gives the tile's surface a pitted appearance.
How Do You Recognize Delaminating Slate Tile?
You can recognize delaminating slate tile by its pitted surface and chalky texture. As flakes of slate break off from the tile, it will expose the calcium oxide underneath. Calcium oxide is white and looks like sidewalk chalk. In extensive cases of delamination, the tile may start to crack apart entirely as the expanding calcium oxide continues to pull it apart from the inside.
How Do You Repair Delaminated Slate Tile?
A delaminated slate tile will still continue to protect your home from the rain, so there's no need to replace it immediately. However, a delaminated slate tile is much weaker than a new one. The extra stress on the tile from the calcium oxide inside it makes the tile more brittle, so it's more likely to break apart entirely if a branch falls on it or if a contractor walks on it. If your slate tile roof has extensive delamination, you prepare yourself for eventually replacing it — the tile will only continue to get weaker as it's exposed to the air, which makes your roof more susceptible to developing a leak if a tile breaks apart in the future.
If you think that your slate roof is delaminating, have the tiles inspected by a roofing contractor in order to determine the extent of the deterioration. A full roof inspection will reveal any tiles that have started to crack apart from oxidation, and it will also give you an idea of how soon you'll need to have your roof replaced. While replacing your entire roof is a big project, it will restore the strength of your slate tiles and protect your roof from leaking.
To learn more, reach out to a roofing service near you, such as Diversified Roofing.
When you have something you like inside a jar, you probably put a lid on it — right? In a way, you can think of your house in the same manner. You like and value the items inside, along with the inside of the house itself. So, it only makes sense that you would protect the interior of your home with a lid. That lid is your roof.
Keep that perspective in mind as you read this blog. Learning more about roofing will feel more interesting if you remember what a roof does: it protects the inside of the home and the people who live in it.