How to Patch a Leaky Slate Roof

Installing a slate roof
  • 1-3 hours
  • Intermediate
  • 50-300
What You'll Need
Slate ripper
Replacement slate
Bib flashing

A slate roof will last for many years and give good service. Sometimes, though, there can be problems with the slate roof and a leak may develop. At that point it’s necessary to replace the slate that’s giving problems. Although you can call in a roofer to do the job, it’s one you can complete yourself quite easily, as long as you have a head for heights.

Step 1 - Remove the Old Slate

The first job is to climb onto the roof and find the slate that’s been causing the problem. By knowing approximately where the leak is inside the house you should be able to pinpoint it on the roof.

Once you’ve found the problem slate you need to remove it. To do this, use the slate ripper to rip off the nail that hooks the slate onto the slate roof. With good wire cutters you might also be able to cut off the head of the nail, which will help. You might find problems removing the nail with the slate ripper. If so, hold the lower end of the ripper away from the roof and then hit the roof with a hammer. Pull out the slate.

Step 2 - Make Temporary Repair

slate roofing

If you’re having problems removing the roof slate and the weather looks bad, you can make a temporary repair. Have roof tar and apply it over any holes or cracks in the roof slate. This will hold for a brief time, but you should carry out the complete repair as soon as possible.

Step 3 - Consider New Tile Size

It’s important to know the correct size of replacement slate for the roof. Start by measuring the space left by the tile. Your new tile needs to fill that width, and it has to be twice as long as the opening, plus another three inches. This will allow a proper overlap on the tile below the replacement.

Step 4 - Replace Tile

slate roof

Slide the new tile into place. Set it so it’s secure and in the correct position. Fix it in place with a nail, making sure the head is flush with the slate. Where there’s a chamfer on the slate, this edge will need to be at the top to slide under the slate above. After doing that, slide a piece of bib flashing under the slate and ensure part of it covers the head of the nail so there can be no leak through the hole.

Step 5 - Tingle

If you’re replacing a slate, you can help fix it in place with a tingle. This is a piece of copper or lead. It should be one inch wide and long enough to extend one inch beyond the replacement slate. Make a hole in one end of the tingle and use a short nail to fix it to the batten under the tiles next to the tile you’ll be replacing. Put the new tile in place and align it. Bend the tingle so the bottom end hooks under the slate to hold it in place.