Chimney repair cost calculator

Is the chimney tall enough? The 3-2-10 check

The top of the crown has to clear two marks, and the higher one wins. The first is 3 ft above the highest point where the chimney passes through the roof, which on a slope is the upslope side. The second is 2 ft above any part of the building within 10 ft, measured level from the chimney. On a pitched roof the roof itself counts as part of the building: it keeps climbing toward the ridge, and the 2 ft mark climbs with it.

The calculator reads that climb from three inputs. Roof pitch is the inches of rise per 12 in of level run; measure it with a level and a tape on the roof, or read it from the roof drawings. The level distance from the chimney's upslope face to the ridge sets how far the roof keeps rising inside the 10 ft radius. Chimney height is taken on the upslope side, from the roof surface to the top of the crown, because that is the short side of a chimney on a slope.

The rise inside the radius is the smaller of the ridge distance and 10 ft, times the pitch over 12. The required height is the larger of 3 ft and 2 ft plus that rise. Worked through the default inputs: a 6/12 roof with the ridge 6 ft away rises 3 ft before the ridge, so the chimney needs 2 + 3 = 5 ft. A 5 ft chimney meets it exactly, with nothing to spare.

Move the ridge to 14 ft away and the answer changes, but not as far as the ridge moved. Only the first 10 ft of roof count, so the rise is capped at 5 ft and the chimney needs 7 ft. The same 5 ft chimney is now 2 ft short. On a gentle 3/12 roof with the ridge 4 ft away, the roof rises 1 ft, 2 + 1 = 3 ft, and the 3 ft minimum above the roof is the mark that governs. A chimney that passes through the ridge has no roof climbing past its upslope face: with a ridge distance of 0 the rise is 0, and the required height drops to the 3 ft minimum.

The roof is not the only thing within 10 ft. A dormer, a parapet, a second-story wall or a higher roof section beside the chimney all count. Enter the height of that part above the upslope roof line in the third field. With a dormer 4 ft above it on the default roof, the candidates are 3 ft, 5 ft and 2 + 4 = 6 ft; the dormer governs, and the 5 ft chimney is 1 ft short. The result names the candidate that set the height, so you can see whether the roof or the dormer is the problem.

Two limits apply. The tool reads the roof as one plane that rises to the ridge; a hip, a valley or a change of pitch inside the radius needs its own measurement. And “3-2-10” is a nickname for R1003.9, not text of the code. The section quoted above is the 2021 IRC as adopted in Hawaii, read on the UpCodes viewer. The edition and any local amendment where you live decide what applies to your house, and the local building department has the last word.

A short chimney is not something a face rate fixes. It appears on a quote as a rebuild or extension of the stack, and the calculator flags the gap when no rebuild line is entered.

When the roof needs a cricket behind the chimney

A cricket, also called a saddle, is a small ridge built on the upslope side of a chimney so that water runs around the stack instead of collecting against it. R1003.20, quoted above, sets two conditions. The chimney's dimension parallel to the ridge must be more than 30 in, and the chimney must not intersect the ridge. Both have to hold.

“More than” is strict. The default 32 in chimney needs a cricket. A 30 in chimney does not, because 30 is not more than 30. A 36 in chimney that passes through the ridge needs none either, since no roof slopes down into its upslope face. The calculator applies the same test, and when a cricket is required but the cricket line of your quote is blank, it says so. Table R1003.20 sets the cricket's height from the roof slope; this tool does not size the cricket itself.

The section also says the joint between cricket and chimney is flashed and counterflashed like any roof-chimney joint. That is why the tool returns the flashing perimeter at the roof line: twice the sum of width and depth, in inches, over 12. For 32 by 24 in it is 2 × (32 + 24) ÷ 12 = 9.33 linear ft; for 30 by 24 in, 9 linear ft; for 36 by 24 in, 10 linear ft.

Flashing is a line with no per-foot price in the records behind this page. HomeGuide prints flashing repair at $300–$1,800 per job (page dated January 22, 2026). Franklin Chimney, a Philadelphia installer, prints $200–$500 for flashing repair and $500–$1,500 for flashing replacement (page dated May 15, 2026). Neither ties its band to a length, so the perimeter is for reading the quote, not for multiplying. Ask whether the price is for resealing the existing step and counter flashing or for replacing it, and over how many feet.

Turn a per-square-foot price into a price for your chimney

Angi is the only publisher in the table below that states a repair price per square foot: repointing at $4 to $25 per sq ft (page by Deane Biermeier, updated Oct 6, 2026, read October 21, 2026). A rate per square foot says nothing about your chimney until you know its square feet, and on a sloped roof the four faces of a chimney are not the same height.

The calculator measures them one by one. The upslope face is the width times the measured height. The downslope face is taller: the roof drops across the depth of the chimney, by the depth times the pitch over 12. The two side faces are trapezoids, short at the upslope end and tall at the downslope end, so each one is the depth times its height at the midpoint.

On the default chimney, 32 by 24 in on a 6/12 roof and 5 ft tall on the upslope side, the upslope face is 2.67 × 5 = 13.33 sq ft. Across 2 ft of depth the roof drops 1 ft, so the downslope face is 2.67 × 6 = 16 sq ft. Each side runs from 5 ft to 6 ft tall over 2 ft of depth, so the pair is 2 × 2 × (5 + 0.5) = 22 sq ft. Total: 51.33 sq ft of masonry above the roof.

Applied to that area, Angi's band reads $205.33 to $1,283.33. It is Angi's band times your area, not a quote; the gap between its two ends is the spread of one publisher's statement. If your quote gives a rate per square foot, for repointing, sealing or a stucco coat, type it in the rate field and the tool multiplies it by the same 51.33 sq ft. At an illustrative $12 per sq ft, the face line comes to $616.

The area also tells you what a lump sum means. A quote that says “repoint chimney” for a set price can be divided by the face area to find the rate it implies, and that rate can be held against Angi's band. Ask whether the price covers all four faces or only the failing ones, because a mason who repoints the weather side alone is pricing a smaller area.

The area is not computed for a chimney that passes through the ridge. The roof falls away on both sides, the faces are not the trapezoids described here, and the slope formula would return a wrong number. Measure those faces on site and enter the face work as an other line.

What four publishers print for the same repairs

The table above holds every price statement read for this page, one row per claim, each with its publisher, its own label and its page date. Two publishers are national cost guides: Angi, by Deane Biermeier, updated Oct 6, 2026, and HomeGuide, by Tara Farmer, dated January 22, 2026. Two are local installers writing about their own market: Franklin Chimney in Philadelphia, dated May 15, 2026, and AAA Timberline in Western New York, dated March 31, 2025, the oldest page in the set.

Read the rows for one repair and the bands overlap without matching. Repointing or tuckpointing sits at $500–$2,500 on HomeGuide and on AAA Timberline, and Angi gives tuckpointing the same $500–$2,500 beside its per-square-foot repointing band. Franklin splits the work in two: $200–$600 for the top courses only and $800–$2,500 for a full face. Crown work runs from Franklin's $150–$400 for sealing up to the $3,000 that Angi and HomeGuide each give for a full crown replacement. Sealing goes from $150–$500 on Angi to $150–$820 on HomeGuide and $200–$500 on AAA Timberline's waterproofing line.

No row is an average, and this page does not average them. Each publisher chose its own labels, its own job sizes and its own market, and none states the size of the chimney behind its figures. Two rows with the same label can describe different work. That is why the calculator never fills a price field from this table: a band shows where one publisher drew its range, and your quote shows what your chimney costs.

Use the table to ask questions. If a quote's crown line sits well above Franklin's patching band, ask whether it is a patch or a new crown. If the repointing line is far above Angi's band applied to your face area, ask how many faces are included and how deep the joints will be cut out.

What owners reported in the Census catch-all category

The Census figures above answer a different question. The American Housing Survey asks owners what they spent on home projects, and job type 19 pools “Chimney/stairs/other exterior additions” into a single category. In the AHS 2023 file, 573 owner reports fall in it, with a lower quartile of $500, a median of $2,100 and an upper quartile of $5,000.

Those reports mix a chimney repair with a new set of exterior stairs and any other addition outside the house. They mix work done by a hired crew with projects where the owner bought the materials and did the labor. And they carry no size: no height, no face area, no count of faces repointed. The median of that category is not the price of a chimney repair, and it is not the price of yours.

So the calculator does not compare your total with it, and nothing on the page changes if your quote lands above or below those quartiles. The table is shown because it is the owner-reported spending figure in the records behind this page that comes closest to chimneys, and it is labeled as what it is: a catch-all.

Read a chimney repair quote line by line

Enter a quote the way it is written, one line at a time. The six lines follow the repair types the publishers above price separately.

• Face rate. A rate per square foot for repointing, sealing or a stucco coat, multiplied by the face area the tool measured.
• Flashing. The job price for resealing or replacing the roof-chimney flashing.
• Crown. Sealing, patching or replacing the sloped slab that closes the top of the masonry.
• Cricket. Building one where the width check says it is required.
• Rebuild. The height of stack to rebuild, taken from the quote, times the rate per linear foot.
• Other. Access, a permit, or any line that fits nowhere else.

A blank field means that line is not part of this job. A zero means it is part of the job but included in another line, so the total counts it as known. With only a flashing line entered at $0 on the low-pitch example, the total reads $0 rather than a missing total.

The total is the sum of the lines you entered and nothing else. On the default chimney, an illustrative face rate of $12, $900 for flashing, $450 for the crown and $600 for the cricket give $616 + $900 + $450 + $600 = $2,566. Those amounts are test figures, not market prices.

Two warnings point at gaps in a quote. If the chimney fails the height check and no rebuild line is entered, the tool says the shortfall is unpriced. If a cricket is required and the cricket field is blank, it says that too. On the 14 ft ridge example, a quote with $900 of flashing, a $600 cricket and 3 ft of rebuild at $160 per linear ft totals $1,980, and only the 2 ft shortfall warning remains: the height check still reads the chimney as you measured it, until the rebuilt height becomes your new measurement.

This split serves the case raised by a Reddit thread in the search results for this topic: a homeowner holding a large rebuild quote and asking whether it is reasonable, with no way to see which part of the number pays for what. Breaking the quote into face, flashing, crown, cricket and rebuild lines, each next to its measurement, is how the calculator answers that question for your own chimney. It does not say whether the work is needed; an on-site inspection does.

Chimney repair cost questions

Read the result with its boundaries

• Masonry above the roof, roof-chimney flashing and the stack only. Flue, liner, cap, damper and fireplace work are not priced here.
• No brick, block or mortar quantity is computed.
• The height check reads the roof as a single plane rising to the ridge. Enter any other part of the building within 10 ft yourself, and confirm the rule with the code adopted where you live.
• The face area is not computed for a chimney that passes through the ridge.
• Every rate and every line is a figure you enter. Published figures are shown with their publisher and date, never as an average.