What Does Chimney Waterproofing Cost in Boston?

Chimney waterproofing prices in Boston by tier

Waterproofing prices step up as more of the chimney top is included in the job. The table shows the three tiers and what each is meant for.

The full-system figure is open-ended on purpose. It starts at $800 and the written quote after inspection sets the actual number, because the scope depends on the chimney.

What the $300 to $500 standard treatment covers

The standard tier is a protective water-repellent applied to brick that is already in good condition. It is the lowest-priced tier and the right choice for a chimney that has no cracks or open joints but gets wet and stays wet.

It is not a repair. A treatment cannot bridge an open joint, rebuild brick that has flaked, or stop water that is entering through a cracked crown or failing flashing. That is the most important thing to understand about this price, because it decides whether $300 to $500 is a good purchase or wasted money.

If the technician finds that your chimney is not ready, the quote will say what has to be repaired first. Spending on waterproofing before the repairs is the common way homeowners pay twice.

Where you land in the band depends mainly on size. A short chimney with one flue costs less than a tall, wide one, and the quote should state the size it is based on.

It also helps to know what a standard job leaves out. It does not include scaffolding, repairs to mortar or brick, or work on the crown or flashing. If the quote is a single price for a single treatment, that is normal for this tier, and the extras are what the inspection is for.

What adding a crown seal does to the price

The $500 to $800 tier adds sealing of the crown, the slab at the very top, to the treatment on the brick. It costs more because the crown is where most of the water lands first, so it is also where protection matters most.

Treating only the sides of a chimney while the top stays cracked leaves the main entry open. If your crown has a few narrow cracks but is basically solid, this tier can be a sensible combination. If the crown is crumbling, the better route is a repair or rebuild, which is priced on the chimney crown repair cost page at $300 to $900 for a repair and $900 to $2,500 for a rebuild.

Ask your quote to separate the crown line from the brick treatment line. You should be able to see what each part costs and what it protects.

What a full system from $800 includes

A full system is the top tier, and it is for chimneys where one step is not enough. It combines the brick treatment with other protective work, and the price starts at $800 and rises with the scope.

What counts as full depends on the chimney. It may mean a large or multi-flue stack, a chimney that has been repaired and now needs protection across all faces, or one with a crown, joints and surrounding details all being addressed together.

Because this tier has no upper figure, a written scope matters more here than anywhere else. The quote should list every step in the system, one by one, and you should be able to see each in your photos. If the list is a single line, ask for more detail.

You also should not pay for a full system if a standard treatment would do. The inspection is where that decision is made.

What moves a waterproofing quote up or down

Several factors set the price inside a tier.

• Chimney size. Taller and wider faces take more product and more time. This is the main driver.
• Number of faces exposed. A chimney in a corner with some faces shared with a wall has less surface than a free-standing stack.
• Access. A chimney on a steep roof, or at the end of a tall house, costs more to reach.
• Surface condition. Brick that is dirty or coated with an old treatment needs preparation first, which adds to the quote.
• Weather timing. Treatment needs dry brick, so the schedule follows the forecast, particularly in a wet Boston spring.

None of these changes the published tiers. They explain why one house falls near the bottom of a band and a similar one near the top.

What has to be fixed first, and what it costs

Most waterproofing disappointments come from skipping repairs. The treatment goes on sound masonry, so anything open or loose is dealt with before it, and those repairs are priced separately.

The usual ones are listed below with their published prices.

• Mortar joints that have crumbled: partial repointing $300 to $700, full $700 to $2,500. See the repointing cost page.
• Failed flashing at the roof: $200 to $2,500 depending on tier, covered on the flashing repair cost page.
• Cracked or crumbling crown: repair or rebuild, as covered in the crown section above.
• Spalled brick: masonry repair at $300 to $700 for basic work, $700 to $2,500 for standard, and from $2,500 for major work.

The inspection tells you which of these apply, in writing and with photos of what the technician finds. If none do, the waterproofing price is the whole bill.

What a written waterproofing quote should list

Older brick homes, triple-deckers and rowhouses across Greater Boston have masonry that has seen decades of coastal weather, so the condition of the brick is part of every quote. Before you approve one, look for these lines.

1. The tier, in plain words: standard, with crown seal, or full system.
2. The faces of the chimney that are included, and whether the crown is part of the price.
3. The type of product, described as a breathable water-repellent.
4. Any preparation, such as cleaning the brick first.
5. A short note on the condition of joints and brick, taken from the inspection photos.
6. Repairs that must come first, each with its own written price.
7. The total, written down before the work starts.

If a quote lacks the condition note, ask why. It is the line that tells you whether the treatment is the right purchase at all.

How to compare two waterproofing quotes

Waterproofing quotes are easy to get wrong because the product is invisible once applied. You cannot judge it by looking, so judge the paperwork.

Check what is being applied. The quote should say whether it is a breathable water-repellent, since masonry has to be able to dry out. A product that traps moisture can do more harm than the rain it was meant to stop.

Check what the quote includes. Does it cover every face of the chimney, and the crown? Is cleaning of the brick part of the price? A cheaper quote that treats only the faces you can see from the yard is not the same service.

Check what the quote assumes. Does it assume the brick and joints are sound? If so, ask who confirms that, and when. A second opinion is free when it comes with a written report from a reputable local chimney company, so you can test a quote that seems too low or too high.

One more test is timing. A company that offers to apply the treatment the same day without looking at the joints or the crown is selling a product, not a fix. A written price after a proper look is the safer order of events, and it is how we work, with photos of what the technician finds.

When waiting costs more, and the $49 credit

Boston masonry takes a beating from freezing weather. Brick that stays wet absorbs water, the water freezes, and each cycle flakes a little more off the face. Left alone, the surface weathers faster and the repair moves into the masonry tiers, where standard repair costs $700 to $2,500.

That is the case for treating sound brick early. It is a $300 to $500 step that is much cheaper than rebuilding the surface later. If water is already coming through the chimney into the house, though, the source is likely a leak, and the chimney leak repair page is the better place to start.

If you approve the treatment, the $49 inspection is taken off the bill. The written price always comes before the work.

To get a treatment priced for your chimney, call (617) 404-9587 or book through the contact page.

Questions homeowners ask