How much does chimney flashing cost?
Short answer. Chimney flashing work usually runs from several hundred dollars for a small chimney with straightforward step and counterflashing to well over a thousand when the chimney is large, needs a new cricket, has masonry repairs or sits on a steep roof. Doing it during a roof replacement is usually the most cost effective time, since the shingles around the chimney are already off.
What goes into the price
- Chimney size. More perimeter means more step flashing and counterflashing.
- Cricket. The residential code calls for a cricket on the uphill side of chimneys more than 30 inches wide. Building one adds framing, sheathing, membrane and metal.
- Counterflashing method. The durable method cuts a groove, called a reglet, into the mortar joints and sets the counterflashing into it. Surface-mounted counterflashing held with sealant costs less up front but needs more upkeep.
- Material. Aluminum and galvanized steel cost less than copper.
- Masonry repairs. Repointing, brick replacement or crown work is often needed at the same time.
- Pitch and height. Steep, tall roofs need more setup.
- Hidden damage. Rotted decking and framing around a long term leak add cost.
Repair vs replace
If the step flashing is sound and only the counterflashing or sealant at the top has failed, a smaller repair may do. If the step flashing was installed as one long piece, has rusted through, or is missing, it needs proper replacement, which means removing and reinstalling the shingles around the chimney.
Insurance
Flashing torn by wind or dented by hail may be covered as storm damage. Gradual leaks from aging flashing generally are not. See chimney leaks and crickets and roof flashing explained.