What Does Chimney Flashing Repair Cost in Boston?

Chimney flashing prices in Boston by tier

Flashing is priced by how much of it needs work. A short tear in one corner is a different job from a whole perimeter that has pulled away from the brick.

Notice that the tiers overlap at their edges, such as $400 and $800. Where a job sits is a judgment call the technician explains in the written scope.

What the $200 to $400 repair tier covers

This is the smallest flashing job, and the one people most hope for. It fits when the metal is mostly sound and one spot has let go.

• A single joint in the metal that has opened a gap.
• A lifted edge on one side of the chimney.
• Old roof cement that has cracked in one place and needs redoing.

If you have a stain and the technician traces it to one small defect, this is where the job lands. The tier is narrow and does not stretch. If the problem turns out to be bigger than one spot, the quote moves up to partial replacement, and you hear that before any work is done.

One caution on price shopping: a very cheap quote that only adds a bead of sealant over a failing joint may fall in or under this tier. It can look fine for a season. Ask the quote to say whether metal is being repaired or only covered.

What partial and full replacement cost you

Partial replacement, $400 to $800

This tier fits a side of the chimney, or a defined stretch of the metal, that has rusted, pulled loose or been poorly installed. The rest of the flashing is left in place. The cost rises with the length of metal replaced and how hard it is to reach.

Full replacement, $800 to $2,500

This tier replaces the metal around the whole chimney. It is wide because chimneys differ so much. A small chimney on a low roof sits near $800. A large or multi-flue chimney, a steep roof, or a design that calls for a new back pan or cricket on the high side pushes toward $2,500.

A back pan or cricket is a small roof-shaped piece that sends water around the chimney instead of letting it pile up behind it. Whether one is needed is a quote line item. It is most relevant on wide chimneys, and you should see it named in writing rather than folded in without comment.

What moves a flashing quote up or down

The tier gives the range, and these factors set the figure inside it.

• Roof pitch and height. A steep or tall roof takes more time to work safely, and the labor shows in the price.
• Size and number of chimneys. More perimeter means more metal. A wide rowhouse stack costs more than a narrow one.
• Roof material. The material the flashing is woven into affects how much has to be lifted and put back.
• Condition of the masonry joint. Counterflashing needs a solid joint in the brick to seat into. If the mortar there has crumbled, that is a separate line.
• Whether the leak has already damaged the inside. Interior stains and wet insulation are repaired on their own estimate.

Two chimneys that look the same from the street can sit in different tiers for these reasons. None of these means the price must be at the top of the range. A written quote should say which factors apply to your roof, so the figure is explained and not a surprise.

What a written flashing quote should list

Ask for these items on paper before you say yes.

1. The tier, in plain words: repair, partial replacement or full replacement.
2. Which sides of the chimney are included, and how much of the perimeter.
3. Whether the old metal is being replaced or only resealed.
4. Whether a back pan or cricket is part of the price, and why.
5. Whether the masonry joint the metal tucks into is included.
6. What is excluded, such as shingles or roof deck repair.
7. The total price, set down in writing before any work.

Photos of what the technician finds go with it. Since the flashing sits where most homeowners never look, the photos let you see the lifted edge or the rusted run for yourself.

How to compare two flashing quotes

Flashing quotes can look far apart when they describe different work, so compare the work first and the price second.

If one quote is a fraction of another, find out whether they cover the same part of the chimney. The low quote may be a sealant touch-up. The higher quote may replace the metal on all four sides. Both can be honest, but only one of them is a lasting repair for a failed assembly.

Ask each company one direct question: after this work, what is holding water out, metal or caulk? Metal that is layered with the roof and tucked into the brick is a real repair. A thick bead of sealant alone is a patch.

Also check what the quote says about the roof itself. Flashing sits in the roofing, so ask whether the quote includes any work on the shingles around it or leaves that to you. A second opinion costs nothing when you bring a written report from a reputable local chimney company.

How Boston roofs and chimneys shape the flashing price

Many Greater Boston homes are older brick houses, triple-deckers and rowhouses, and the chimney often rises through a roof that has been re-covered more than once. That history matters to a flashing quote.

Older roofs sometimes hide layers of past repairs, with roof cement smeared over earlier cement. The technician has to lift and read what is there before the right tier is clear, which is why the inspection comes before the price. It is also why two similar-looking houses on the same street can get different quotes.

Chimneys on a sloped roof need metal that steps down the slope and a piece that sheds water on the high side. Chimneys that rise at the ridge need less of this, which can keep the price lower. Chimneys on a flat or low-slope roof are a separate case, and the quote will say how the metal is detailed there.

Coastal weather also takes a toll. Salt air speeds up rust on thin metal, and nor-easters push rain sideways under any edge that has started to lift. None of this changes the published tiers, but it helps explain why the written scope for your house reads the way it does.

What waiting costs on a flashing problem

Flashing failures are cheap to fix and costly to leave. Water runs behind the metal and down the roof deck, then into the attic and the ceiling below. You usually see it as a stain beside the chimney after a heavy rain or a wind-driven storm, long after the water began to get in.

That is how a flashing repair becomes a leak repair. Leak repair is priced at $400 to $3,000, because the source can sit in several places and the interior damage is added to it. Our chimney leak repair page explains how the source gets traced.

Greater Boston adds pressure. Winter ice builds up behind a chimney and works under the metal, and freeze-thaw cycles pry open joints that were only slightly loose in autumn. A $200 to $400 repair in October can be a $400 to $800 partial replacement by spring.

What is quoted separately, and the $49 credit

The flashing prices cover flashing. These related items are quoted in writing after the inspection:

• Shingle or roof deck repair around the chimney.
• Damaged brick or mortar at the top, which has its own pages on repointing cost and the broader chimney repair cost page.
• Waterproofing of the chimney body, which is priced separately.
• Water damage inside the house.

Approving the flashing job turns the $49 inspection into a credit against it, so the visit costs you nothing extra. Declining leaves you with the written finding and photos.

To have your flashing looked at, call (617) 404-9587 or book on the contact page. Expect a call ahead and a 3-hour arrival window.

Questions homeowners ask