Why does a Mission Hills roof need a different kind of repair?
A roof of red clay Mission tile is built to be read in a particular way. Each course overlaps the one below, the tiles are held by their own shape and by a few clips or mortar beds, and the decorative vents sit on a flashing of their own. A crew that treats the roof as a shingle job will break more tiles than it saves.
The technician works from the ridge and the ladder and lays boards across the field where the weight must go. The tiles are lifted and re-set in the order they were laid, so the course keeps its line. The repair is judged by whether it looks right from the street and whether it sheds the water from the next storm.
What do the decorative clay vents add to the risk?
A decorative clay vent is a small fixture with a cap and a seat, and it is often the place where water first enters a tile roof. The seat is flashed into the roof and the cap is set to shed rain, but both can loosen over time and let water run down the vent body into the framing below.
A vent repair is checked from the attic as well as from the roof. A stain on the boards beneath the vent, or a soft patch on a rafter, shows where the water has been. The flashing is re-made and the cap is re-set, and the attic boards are dried before the room below is closed.
How is the heritage look kept on a repair?
The first step is to salvage any sound tile from a part of the roof that will not be seen, such as a rear slope or an outbuilding. Those tiles are used where a close match is needed. Where the stock is gone, a tile of the nearest profile is chosen and set on a discreet slope first, so the owner can see the match before the main repair goes ahead.
The owner is told plainly what matches and what does not. A visible mismatch is not a leak, and it does not always justify a full re-tile. The choice is made on the facts of the roof and the owner's wish, and both are written into the scope.
