Slate Roofing Repair: What is Involved and How to Do It


Slate roofing is just about the best looking and most durable roofing system you can get. They have the potential to last from 75-200 years. That doesn’t mean you can just ignore them for decades though. Slate tiles and roof need upkeep and they are prone to damage and deterioration. You can keep care to a minimum if you catch problems early.

Problems And Solutions

repair Slate RoofingSlate roof or individual tiles can fail in many ways. Over time and due to natural weathering, slate can fall apart by delamination, a process where thin layers of the slate flake off and the slate becomes spongy. This happens throughout the slate, so a tile cannot just be flipped over and reused. These weathered slate tiles are prone to breaking and chipping as well. Improper installation and the use of improper nails can lead to breakage. Also, breakage from events such as falling trees can cause breakage. If over 20% of a slate roof has damage or disrepair, it is advisable to have the entire roof replaced by a slate roofing repair specialist. If less than 20% of the roof/tiles are damaged, individual tile replacement is permissible. Another common problem is flashing deterioration and failure. If the flashing is leaking, you should not just try to seal it up with tar or mastic. This is not a solution, and will leak again. The flashing will need to be replaced. Likewise, you cannot repair a broken or deteriorated tile with tar or mastic. It must be replaced with new or salvaged tile.

How To Replace One Or More Tiles

Honestly, the best way to replace tiles is to hire a slate roofing repair professional. The damaged slate tile will be removed by cutting or ripping out it’s nails with a special tool called a ripper. The old slate should slide out, but if it does not it will be hit with a slate hammer and pulled out. The new or salvaged slate will be pushed into position and nailed in. To keep moisture out of the new nail hole, a piece of copper is slid under the joint of the above two slate tiles and over the nail hole. Other ways to secure the new tile can include:

  • metal hooks
  • metal clips
  • metal straps bent up over the edge of the new tile

Always check for rotted wood, damaged flashing and protruding nails when replacing tiles. A slate roofing repair specialist will know what to look for and what should be replaced. This is one of those times when it’s best to call an experienced professional.