Chimney & fireplace
Chimney Flashing Cost Calculator
Prices chimney flashing, the roof detail that leaks more than any other.
Result
A planning estimate, not a quote. Access, the age of the equipment, what is found once it is opened up and local labour rates all move the real figure, sometimes a long way.
Get a Free Business AuditHow the calculation works
Hours times crew times rate, plus materials and the call-out. Flashing a chimney properly is a layered detail rather than a strip of metal: step flashing woven into the shingle courses up each side, counter flashing let into or surface-mounted on the masonry to cover the step flashing's upper edge, an apron at the front, and on a chimney above a certain width a cricket, which is a small built-up roof behind it to shed water around rather than letting it pond against the masonry.
What moves the number
- Chimney width, since a wide chimney needs a cricket behind it.
- Whether counter flashing is let into the masonry or surface mounted.
- Roof material, which changes how the step flashing integrates.
- Whether masonry repair is needed where the counter flashing seats.
Where this one goes wrong
A chimney penetrating a roof is the most leak-prone detail on most houses, and sealant is not flashing. Caulking around a chimney addresses the symptom for a season while the water keeps getting in behind, and the damage appears as a stain on a ceiling some distance from the chimney. A wide chimney on a sloping roof needs a cricket, because without one water and snow pond against the upslope face and eventually get in whatever the flashing does. Cutting counter flashing into a mortar joint rather than surface-sealing it to the brick is what makes the detail last.
Before you quote
- Fit a cricket behind a wide chimney rather than relying on flashing alone.
- Let counter flashing into a mortar joint where possible.
- Weave step flashing into the shingle courses, not over them.
- Repair the masonry where the counter flashing will seat.
Where the rules come from
Questions
About this calculator
Why does my chimney leak when the flashing looks fine?
Because flashing is a layered detail and the visible metal is only part of it. Water can get behind surface-sealed counter flashing, past step flashing laid over rather than woven into the shingles, or pond against a wide chimney with no cricket. Sealant over the top addresses none of those.
What is a cricket and do I need one?
A small built-up roof structure behind a chimney that sheds water and snow around it rather than letting it pond against the masonry. Chimneys above a certain width on a sloping roof need one, and without it that upslope face is where water eventually gets in regardless of the flashing.
Can chimney leaks be fixed with caulk?
Only temporarily. Sealant around a chimney hides the path for a season while water continues entering behind it, and the damage shows up as a ceiling stain away from the chimney. The flashing layers have to be correct, because that is what sheds water rather than resisting it.
The formula
total = hours x people x rate + parts + call-out, then sales tax
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How to use this calculator
- Hours on site (h). Enter your own figure; the page starts at 2 h.
- People needed. Enter your own figure; the page starts at 1.
- Labour rate charged ($). Enter your own figure; the page starts at $125.
- Parts and materials ($). Enter your own figure; the page starts at $65.
- Call-out or diagnostic fee ($). Enter your own figure; the page starts at $95.
- Sales tax (%). Leave at zero if you are quoting before tax.
The result updates as you type, so you can try a figure, see what it does to estimated total, and change it back. Nothing you enter is sent anywhere or saved.
A worked example
These are the figures the calculator opens with. Every number in the results column below is produced by the same calculation the page runs, so you can follow it through before putting your own figures in.
What goes in
| Input | Value |
|---|---|
| Hours on site | 2 h |
| People needed | 1 |
| Labour rate charged | $125 |
| Parts and materials | $65 |
| Call-out or diagnostic fee | $95 |
| Sales tax | 0% |
What comes out
| Result | Value |
|---|---|
| Estimated total main result | $410 |
| Labour | $250 |
| Before tax | $410 |
| Sales tax | $0 |
About $410: $250 of labour, $65 of parts and a $95 call-out.
How sensitive the answer is
Holding everything else steady and changing only labour rate charged, this is what happens to estimated total. It is worth knowing which of your inputs the answer actually hinges on, and which barely move it.
| Labour rate charged ($) | Estimated total |
|---|---|
| $63 | $286 |
| $94 | $348 |
| $125 example above | $410 |
| $188 | $536 |
| $250 | $660 |
Every other input is held at the example value while this one changes, which is not how a real job behaves. Treat it as a guide to which number matters most, not as five separate quotes.
What each figure means
- Hours on site (h)
- Measured in h, between 0 and 400, starting at 2 h.
- People needed
- A number, between 0 and 40, starting at 1.
- Labour rate charged ($)
- A money amount, starting at $125.
- Parts and materials ($)
- A money amount, starting at $65.
- Call-out or diagnostic fee ($)
- A money amount, starting at $95.
- Sales tax (%)
- Leave at zero if you are quoting before tax.
What the results tell you
| Result | What it is |
|---|---|
| Estimated total | The headline result. A money figure. |
| Labour | A money figure. |
| Before tax | A money figure. |
| Sales tax | A money figure. |
Estimating is the easy part
The jobs you never hear about cost more than the ones you mis-measure. BDEVY builds the marketing, systems and automation that bring them in.