Old slate and tile roofs tend to have old chimneys, and when inspecting your roof, we treat the chimney tops as part of the roof. If the chimney mortar, or flashing leaks, then water can find it’s way inside.
Common maintenance of chimneys includes:
- Pointing. Over time, mortar wears out- crumbling or cracking- and needs to be ground out (typically to a depth of about 1 ½ inches) and replaced with fresh mortar. Then it requires “striking”, where it is compressed and tooled to match the style which it was originally. Finally, the bricks are carefully cleaned to remove any mortar that got onto them.
- Flashing. Chimneys have metal at their base that is tucked into the mortar joints and is woven into the slate or tile, which keeps water out. Eventually, the metal deteriorates and needs to be replaced. Slates or tiles are carefully removed to uncover the old metal, which is also removed. Then new flashing (usually copper) is installed and the salvaged slate or tiles are replaced.
- Chimney Caps. Rain, birds, or bats can be kept out by installing a chimney cap. Standard or custom built caps are available in a wide variety of styles.
- Rebuilding. If the mortar is too deteriorated, then the chimney top may need to be rebuilt. Loose bricks and mortar are removed to just below the roof line, then the chimney is built back up using solid new bricks to match the original, and new flashing is installed.
- Removal. If the chimney needs work, and it is no longer used, removal may be the best option. It can be torn down the just below the roof line, then new sheathing installed over the hole. Matching slate or tiles can the be installed and all evidence of the chimney is gone.
Chimney Cap: Fabrication & Installation