Chimney Caps, Crowns and Flashing in Greater Burlington, Vermont
Close to every chimney leak comes from one of three places, and they are worth telling apart before anyone starts work. The cap is the metal hood sitting over the flue opening; with none fitted, rain and snow drop straight down onto the damper, the smoke shelf and the firebox. The crown is the sloped masonry surface on top of the stack; when it cracks, water runs down inside the brickwork itself and does its damage out of sight. The flashing is the metal that seals the joint where the chimney passes through the roof, and it is the single most common source of a stain on a ceiling next to a chimney. The symptom often points at the wrong one. Water in the firebox commonly means the cap or the crown; a stain on the ceiling beside the chimney commonly means the flashing.
What a caps, crowns & flashing visit can cover
- Identifying which of the three is letting water in
- Cap supply and fitting, sized to the flue with a spark and animal screen
- Multi-flue caps where one stack carries more than one flue
- Crown repair, resurfacing or full recasting with a proper overhang and drip edge
- Step and counter flashing repair or replacement
- Removing failed tar patches, not adding to them
- Breathable water repellent once the components are sound
- Photographs from the roof so you can see the finding yourself
Reasons people book caps, crowns & flashing
- Rain or snow falling directly into the firebox
- A brown stain on the ceiling or wall where the chimney passes through
- Water running down the inside of the chimney breast
- A visibly cracked, crumbling or missing crown
- No cap at all, or a cap that has blown off or rusted through
- Birds, squirrels or bats getting into the chimney
- Rusted, lifted or tar-patched flashing at the roofline
- Damp or musty smell in the room around the chimney after rain
What happens in caps, crowns & flashing, in order
- Describe where the water shows up inside and whether it tracks with rain, with snowmelt or with wind direction.
- We inspect the cap, crown and flashing together, because fixing one while another is failing does not stop the leak.
- You get a scope naming the component responsible and what is being done to it.
- Work is completed and, where the leak was intermittent, we tell you what to watch for in the next heavy rain.
What changes the quote for caps, crowns & flashing?
Prices come from the independent company that visits your property, because the work is quoted and carried out by that company. These are the variables that move the number, so you can read a quote correctly and compare two of them.
How chimney quotes are built, and what makes two comparable →If caps, crowns & flashing turns out not to be what you need, the full list of chimney and stove services sets out what separates each one, and the chimney problem pages work back to it from the symptom you can see.
- Which component is at fault and whether more than one is
- Number of flues in the stack, since multi-flue caps are made to size
- Cap material and whether stainless or a coated steel is appropriate
- Whether the crown can be resurfaced or must be broken off and recast
- Flashing type and whether the roof covering has to be lifted to do it correctly
- Roof pitch, height and safe access
- Whether previous tar patching has to be removed first
- Season, since crown casting has temperature limits
Which component is letting water in
Where the water appears inside is the most reliable single clue, and it is the diagnosis people most often get backwards.
| Where the water shows up | Most likely source | Also check | Wrong repair people buy |
|---|---|---|---|
| Ceiling or wall stain at roof level beside the chimney | Flashing | Ice damming; roof covering condition | A new cap |
| In the firebox or on the damper after rain | Missing or failed cap | Crown condition | Flashing |
| Inside the masonry, white chalky staining outside | Cracked crown | Open mortar joints; spalled brick | A surface sealer |
| Damp smell in the room but no visible stain | Slow leak or condensation in the flue | Flue sizing; unlined chimney | Sweeping alone |
| Only in wind from one direction | Flashing or masonry on that face | Termination height | Whole-stack waterproofing |
| Only during snowmelt | Ice damming forcing water under flashing | Roof and gutter detail | Crown recasting |
When caps, crowns & flashing is ordinarily booked
Spring through fall for crown work; caps year round
What can be done in which season in Vermont →Common questions about questions about caps, crowns & flashing
How do I tell whether it is the flashing or the chimney itself?+
Where the water appears is the best first clue. A ceiling stain beside the chimney, at the level where it passes through the roof, points at flashing. Water in the firebox or on the damper points at the cap or the crown. Water inside the masonry with white staining points at the crown.
What does a chimney cap do?+
It keeps rain and snow out of the flue, keeps birds and animals out, and its screen stops sparks leaving the top. A chimney without one is an open pipe into your house, and the damage it causes to the damper, smoke shelf and firebox accumulates quietly.
Is a cap required?+
Not universally mandated for every chimney, but it is close to universally sensible, and it is very often what an inspection recommends first because the cost is small relative to the water damage it prevents.
What is the difference between the crown and the cap?+
The crown is masonry: the sloped top surface that throws water clear of the flue tile and off the brickwork. The cap is metal and sits over the flue opening itself. Different materials, different failure modes, different repairs.
Why do crowns crack?+
Many were built as a thin mortar wash instead of a proper cast crown with an overhang and a drip edge. A thin wash has no reinforcement, sits directly against the flue tile, and cracks with the first few freeze-thaw cycles. Then water goes straight into the masonry.
Can a cracked crown be patched?+
Small cracks in an otherwise sound crown can be sealed with a flexible crown coating. A crown that has broken up, lost pieces or was never more than a thin wash is recast, because patching something that failed because it was too thin repeats the failure.
What is step flashing and counter flashing?+
Step flashing is the pieces woven into each course of roofing alongside the chimney. Counter flashing is the metal let into the masonry joints above it, lapping over the step flashing. The pair sheds water. When people tar over a leak, they are commonly covering failed counter flashing.
Why is tar a bad flashing repair?+
Because it is a coating over a joint that needs a mechanical overlap, it is rigid where the joint moves, and it fails within a few seasons, commonly invisibly, since it still looks like a repair. It also has to be removed before a proper flashing repair can be made.
Is a chimney leak a roofer's job or a chimney job?+
It depends which component failed, so identifying it first matters. Flashing sits at the boundary and either trade may handle it. Crown and cap work is chimney work. A leak diagnosed as flashing when the crown is the cause gets repaired twice.
There are animals in my chimney. Will a cap solve it?+
A screened cap keeps them out, but it must never go on while something is living in there. Chimney swifts are federally protected migratory birds and cannot be sealed in. The sequence is: establish what is nesting, resolve that, then cap.
What is the white powdery staining on the outside?+
Efflorescence: salts drawn out of the masonry as water moves through it and evaporates at the surface. Harmless in itself and it is a reliable sign that a significant amount of water is travelling through that brickwork, commonly from a failed crown above.
Should I waterproof my chimney?+
Only after the cap, crown, flashing and mortar are sound, and only with a vapour-permeable masonry repellent. A film-forming sealer over damp masonry traps water inside the brick where it still freezes, which makes the next winter worse, not better.
How long should a cap last?+
A stainless cap is a long-term component. Galvanised and coated steel caps rust out, and in a wet Vermont winter they do it faster than the label suggests. If a cap is rusting through, the screen has commonly gone first.
Can this work be done in winter?+
Cap fitting can often be done in cold weather if the roof is safely accessible. Crown casting and flashing bedded in mortar need temperatures that let the material cure, so those get scheduled for the warmer months and temporary protection used in the meantime.