*Put your safety harness on.
*ID broken slate that affects the integrity of slate roof system.
*Properly set up ladder, jacks/plank and chicken ladder to access the ridge to install the safety bracket.
*Connect the lanard to the secured safety bracket and your harness.
*Proceed to the slate removal and replacement area.
*Place the slate ripper under the broken slate, slide it up and hook it on the nail that is securing the slate. Slide the ripper up and down with force til the nail pulls out. Perform the same procedure for the remaining nail on the opposite side.
*Once the nails are removed slide the ripper up and down in the opening clearing any additional debris.
*Cut the new slate to the size of the slate that was removed. Unless improper headlap was noticed, then notifiy your supervisor (Cutting with the back side of the slate facing up will provide the proper beveled edge when it is flipped over and installed)
*Headlap is simply the portion of the slate that is overlapped by two layers of slate (from the next two courses).
Headlap is what makes the roof watertight. Standard headlap is 3″ and should be adhered to unless the pitch is very steep (greater than 20/12), in which case you can reduce headlap to 2″, or very shallow (less than 6/12), in which case headlap should be increased to 4″ as moisture will not shed as readily. Further adjustments to headlap are sometimes made based on climate. (wet or dry) and prevailing winds. It should be mentioned that under no circumstances should the installer try to “stretch” the slate by “cheating” on the headlap.
*Slide the slate into place and mark a spot on the new slate with the pick side of your slate hammer. This will be in between the key ways of the course above where the slate is being replaced.
*Pull the slate out and transfer the scrib mark to the back side of the slate then poke a hole with the pick side of your slate hammer. This is performed with a quick thrust of the hammer and will take a bit of practice but will be easily learned.
*Slide the slate back into place and secure it with a 1 1/2″, 10 gauge hardened copper roofing nail. The nail is typically placed within the keyway 1″ below the bottom edge of the slate above the one you are working on. Be sure to not over drive the nail. A punch comes in handy to set the nail perfectly.
*Once the slate is secured in place a 20 oz. copper bib flashing will be slid into place to cover the exposed nail. The bib flashing should go from the head of the slate and covering the nail by 3″. Cup the copper bib flashing to ensure friction between the slate the copper. This will ensure the bib flashing will remain in place.