FAQ & Glossary of Terms

Frequently Asked Questions

Q: How often should my chimney be cleaned?
A: This depends on how much it is used. A wood stove used for heat may need to be cleaned several times a year. Any time you can see 1/8th inch of creosote build up on the flue, cleaning is recommended. Once a year is normal for any chimney with a season's use. At Oregon Chimney, a full safety and structural inspection is given with the sweep.

Q: Why do chimneys need to be cleaned?
A: When wood is burned the smoke and exhaust goes up the flue. There it cools and dries and forms a deposit called creosote on the insides of the chimney walls. Creosote is a flammable material and can catch on fire inside the chimney. If it does catch it can burn even hotter than the fire in the fireplace and can spread to the wood framing and cause a house fire.

Q: Why should chimneys be waterproofed?
A: Water damage is the main reason chimneys need repair. If a chimney is waterproofed it will last much longer before it has problems, in most cases. Also, in our area, even chimneys in good repair have been known to leak in periods of heavy rain as the bricks are porous and can allow water to pass through to the inside of the house.

Q: Why is a chimney cap needed?
A: Unless there is a cap on the top of the chimney, rainwater gets in the chimney and, over time, causes damage. Water damage is the most frequent reason chimneys need to be repaired. Some of the problems from water damage include:

  • Water damage on ceilings, basements
  • Rusted dampers
  • Fire boxes cracking and wearing out faster
  • Mortar damage
  • Loose bricks
  • Brick faces splitting
  • Water leakage
  • Houses with "ash tray smell"

Caps also prevent birds and other animals from coming down the chimney.

Q: How much does a chimney cleaning cost?
A: There are different prices depending on what is being cleaned. Prices start around $90.00, but it is best to call for a phone quote.

Q: What can be done if a damper cannot be opened or closed fully or is missing?
A: Sometimes a damper can be repaired but most often a replacement damper is in order. Replacement dampers go on the top of the chimney and serve the dual purpose of keeping heat in when they are closed and also acting as a chimney cap.

Q: What causes fireplaces to smoke?
A: Fireplaces smoke for many reasons. Here are a few main ones:

  • Some need an outside air vent so combustion air is provided to the fireplace.
  • Sometimes the fireplace opening is too high and the ceiling of the house competes with the chimney for the smoke. In this case a smoke guard can be installed to effectively lower the height of the firebox.
  • Another common smoke problem is caused by the wind. A stiff breeze blowing across the top of the flue can interrupt the draft and cause smoke to puff into the house.

Wind directional caps can correct this problem.

Q: What is tuck pointing?
A: Tuck pointing is where mortar joints between bricks are repaired. Usually this is done by grinding out the bad, soft or damaged areas and putting new mortar in.

Q: Why does brick need tuck pointing?

A: Mostly water damage and wear and tear. With 70 or 80-plus year-old houses the mortar that was used often did not contain much cement and is softer to begin with than mortar available today. Normally even after 30 or 40 years in our Oregon weather there can be a significant deterioration in the condition of mortar.

Q: What is the value of tuck pointing?
A: It repairs damaged areas and makes the brick work last longer. It keeps the brick from getting loose and helps one avoid having to rebuild. It also keeps water from penetrating and causing damage.

Q: When do you tuck point versus rebuild?
A: You can tuck point when the mortar is damaged but the bricks are not loose. Once the bricks become loose they must be torn off to where they are solid, then they must be re-laid or replaced.


Glossary of Terms

Ash dump: A small opening in the floor of the firebox into which the ashes can be pushed.

Bonding agent: A liquid mixed into mortar to help it bond (stick) more completely.

Bad brick: Brick that has become soft from age and/or furnace exhaust and that won't resist the weather or bond well enough to be repaired with new mortar. It needs to be replaced with new brick.

Cement: A compound usually mixed with water and sand that dries very hard.

Chemical flue wash: A substance applied to the flue to remove creosote glaze (we don't do or recommend doing this).

Chemical wash: A chemical that is applied to your chimney on the outside to clean and remove surface dirt and some kinds of damage, usually due to water/weather/flue leakage.

Clean out door: A metal door installed above the smoke shelf so that area can be cleaned out. It also makes it unnecessary to remove wood stove inserts from the firebox for cleanings and inspections.

Course: A horizontal layer of brick.

Corbel: A fancy arrangement of brick, usually at the top of a chimney.

Creosote glaze: The residue left in your flue after creosote flakes have burned.

Crown: A layer of cement at the very top of the chimney that protects the bricks and mortar from the wear and tear of the weather. Every chimney has (or has had) a crown. A good crown usually lasts between 20 and 30 years before wearing away and needing replacement.

Damper: A metal blade inserted in an assembly that opens and closes a flue. It acts as a door to the flue.

Efflorescence: The powdery deposit the results from water evaporating from brick and mortar. It means that water has completely penetrated the chimney and the chimney needs waterproofing.

Firebox: The inside of the fireplace where the wood is burned.

Fire brick: Brick built to withstand the heat of fire inside the firebox.

Fire brick splits: Fire brick that is made 1/2 as thick as regular fire brick. Made for wood stoves and other special installations.

Fireclay: A substance mixed in with mortar to resist heat. It goes in the firebox.

Flashing: Two sections, top (counter, the chimney part) and bottom (step, the roof part) of metal attached to your roof and chimney to prevent water leaks. This must be metal and not just tar, to fully protect against leaks.

Float: A thin layer of mortar applied to seal brick.

Flue: The inside of your chimney that channels the smoke up and out.

Flue tile: A square, rectangle, or round piece of clay or pumice, hollow in the center, that lines the inside of the chimney. It gives a flue longer life than a regular brick flue. It is also a single piece at the top of the chimney.

Hearth: The flat area in front of your fireplace, usually made of brick.

Hearth facing: The vertical area at the fireplace, along the sides and above.

Insert: A wood stove placed into an existing fireplace opening.

Leeching: Water moving through the walls of a chimney and reacting with the chemicals causing a white residue (efflorescence).

Lentil (bar): A cast iron L-shaped bar at the top of the opening of your fireplace that supports the brick over the firebox opening.

Liner: A metal pipe that is put inside the flue to make a separate chamber to take out exhaust fumes. They are used with furnaces and wood stoves, not in normal fireplaces.

Mortar: A combination of cement, lime, sand and usually a bonding agent. It’s put between brick to hold them together.

Parge: A coating of mortar on the inside of the flue for more durability.

Popped joints: Mortar joints that are pushed out by the action of the brick contracting and expanding due to heat fluctuations.

Popping: Bricks that are cracked or have had the brick face break off. This is due to water absorption.

Prep: Short for preparation, to remove or clean or prepare for repair work.

Rain caps: A metal top that goes on the top of your chimney to keep rain, birds, animals, leaves and wind out of your chimney. Also called a flue cap, chimney cap, etc.

Rebuild: To tear down and re-do a structure, using the same or new brick.

Scaffolding: Metal brace and plank structures used for mason and contractors to stand on while doing high work.

Security pipe: Double-wall insulated pipe for outside use with wood-burning appliances.

Seeping: Water moving through brick and mortar.

Shoulder: The part of your exterior chimney that moves out to be large enough for the firebox.

Shoulder caps: Metal or cement plates that cover the shoulders of the firebox to prevent water penetration.

Skim coat: A watery, thin layer of mortar or cement.

Smoke shelf: A flat area behind the damper the helps the chimney draft correctly.

Spalled: Bricks that have broken faces due to water penetration.

Strike: To shape the mortar between the bricks. This is done with a tool called a striker.

Sweep: To clean the flue, smoke shelf and firebox of soot and buildup to make it safe to use your fireplace, wood stove, etc.

Spot-point: To tuck-point just the holes or gaps as needed.

Tear down: To remove loose bricks and mortar, as tuck pointing cannot be done if bricks are loose.

Top-closing damper: A damper assembly that is attached at the top of your chimney.

Tuck-pointing: The act of removing soft or bad mortar and replacing it with good, new mortar. The soft or bad mortar is removed to the point where it is hard again, at least 1/4 of an inch so a good bond can be gotten with the new mortar. This is considered to be normal maintenance for a chimney. The amount of time in between tuck-pointing varies, depending mainly on the weather. If bricks are loose they should not be tuck-pointed, but replaced or re-lain.

Waterproofing: A chemical solution applied to chimneys to help stop water penetration and damage. It is not permanent, but most manufacturers say it will last 10 years.

Feel free to call us with any questions!