Water and Your Masonry Chimney

Water and Your Masonry Chimney

The chimney is one of the most taken-for-granted parts of a home. Typically it tends to receive neither the attention nor the concern usually accorded other household service systems. The fact that chimneys may do their job reasonably well, even when abused or neglected, contributes to this atmosphere of indifference. Chimneys are far from the passive black holes that most people assume them to be. They perform several vital functions, and their simple appearance misrepresents their complex construction and performance requirements. A chimney deteriorated by constant exposure to the weather can be a potential safety hazard. Weather-damaged lining systems, flue obstructions and loose masonry materials all present a threat to residents. Regular chimney maintenance is essential to prevent damage, deterioration and future high-cost chimney repairs.

Masonry Chimneys
A masonry chimney is constructed of a variety of masonry and metal materials, including brick, mortar, concrete, concrete block, stone, flue tile, steel and cast iron. All masonry chimneys contain combinations of, or possibly all of, these materials, most of which are adversely affected by direct contact with water or water penetration.

Water Penetration
All masonry chimney construction materials, except stone, will suffer accelerated deterioration as a result of prolonged contact with water. Masonry materials deteriorate quickly when exposed to the freeze/thaw process, in which moisture that has penetrated the materials periodically freezes and expands causing undue stress. Water in the chimney also causes rust in steel and cast iron, weakening or destroying the metal parts.

Note: While most stone is not affected by water penetration, large amounts of mortar are required to bond the stone together properly. Therefore, a stone chimney – just like a brick chimney – should be protected from the effects of water penetration.

Water penetration can cause interior and exterior damage to your home and masonry chimney including:

• Rusted damper assemblies
• Deteriorated metal or masonry firebox assemblies
• Rusted fireplace accessories and glass doors
• Rotting adjacent wood and ruined wall coverings
• Water stained walls and ceiling
• Clogged clean out area
• Deteriorated central heating system
• Stained chimney exterior
• Decayed exterior mortar
• Cracked or deteriorated flue lining system
• Collapsed hearth support
• Tilted or collapsed chimney structure
• Chimney settlement

In addition, when water mixes with creosote in a wood burning chimney system, it will generate a highly disagreeable odor that can permeate a home. 

Preventing Water Damage
Chimney caps, also called rain covers, are probably the most inexpensive preventive measure that a homeowner can employ to prevent water penetration and damage to the chimney. Chimney caps have long been recognized as an important chimney safety and damage prevention component. Underwriters Laboratories (UL) specifies that any chimney lining system that is to be listed to their test standard must include a chimney cap. 

Chimneys have one or more large openings (flues) at the top that can collect rainwater and funnel it directly to the chimney interior. A commonly-sized flue has the potential to allow large amounts of rain or snow into the chimney during just one winter when freeze/thaw cycles are common.

Chimney caps also provide other benefits. A strong, well-designed cap will prevent birds and animals from entering and nesting in the chimney. Caps also function as spark arrestors, preventing sparks from landing on the roof or other nearby combustible material. 

A chimney cap should be easily removable to facilitate inspection and cleaning. For a long and effective service lifetime, a cap should be constructed of sturdy, durable and corrosion resistant material. Caps may be designed to cover a single flue, multiple flues, a large portion of the chimney or the entire chimney top. A full coverage chimney cap usually represents a larger initial investment. However, it is probably the best investment for long-term protection because of its ability to protect the entire chimney crown.

Repair or Replace a Damaged Chimney Crown
The chimney crown (also referred to as the chimney wash) is the top element of a masonry chimney. It covers and seals the top of the chimney from the flue liner to the chimney edge. The crown should provide a downward slope that will direct the water from the flue to the edge of the crown. The overhanging drip edge, by directing the run-off from the crown away from the chimney, helps prevent erosion of the brick and mortar in the chimney’s vertical surfaces. 

Most masonry chimneys are built with an inadequate crown constructed from common mortar mix that is designed for years of weather abuse without cracking, chipping or deteriorating. A proper chimney crown should be constructed of a Portland cement-based mixture and cast or formed so it provides an overhang projecting beyond all sides of the chimney by a minimum of two inches. The flue liner tile should also project above the crown a minimum of two inches.

Repair Deteriorated Mortar Joints
Deteriorated mortar joints on the chimneys exterior are entry spots for water. Proper mortar joints have no gaps or missing mortar and are shaped in a way that directs water out of the joint. When mortar deteriorates from exposure to weather, it becomes much more absorbent. A common repair for deteriorated mortar joints is called repointing. In this process, the existing mortar joint is cut to an appropriate depth and the joint is repacked with new mortar. The joint is then cut to form a concave surface that will direct water out of the joint. A good repointing job, using proper materials, will give the chimney a much longer life span, and often will enhance its appearance. 

Repair or Replace Flashing
Flashing is the seal between the roofing material and the chimney. Flashing prevents rainwater or snow melt from running down the chimney into living spaces where it can damage ceilings and walls and cause rot in rafters. The flashing is the expansion joint between two dissimilar materials. It is designed to allow both the roof and the chimney to expand and contract at their own rates without breaking the waterproof seal in either area.

Install a Cricket to Stop or Prevent Leaks
If the chimney is located on the low side of the roof where water run-off is directed against the chimney, the installation of a cricket will afford additional protection against water leaking into the home. A cricket is a water deflector that serves to direct rainwater away from the chimney. Crickets are recommended on chimneys more than 30-inches wide and they are especially important on steep roofs.

Waterproof Your Chimney
Most masonry materials are porous and will absorb large amounts of water. Common brick is like a sponge, absorbing water and wicking moisture to the chimney interior. Defective mortar joints or the use of improper mortar or brick can greatly increase the tendency to absorb and convey water to the interior of the masonry chimney.

Several products have been developed specifically for use as waterproofing agents on masonry chimneys. These formulas are 100% vapor permeable, which means that they allow the chimney to breathe. Therefore, water that has penetrated and the vapors produced when the chimney dries out or the water vapors produced during use are allowed to escape, while the waterproofing agent prevents water from entering from the outside. These products usually have a five- to ten-year warranty. Paint or clear sealers should never be used as a waterproofing agent because they will trap water vapors and moisture inside the chimney causing further deterioration.

Waterproofing is a preventive measure. When damage or deterioration (gaps, voids, cracks, missing mortar, etc.) already exists in a masonry structure, the chimney should be repaired before the waterproofing agent is applied. The chimney exterior may also need to be cleaned before the waterproofing material is applied.

All content in this post Copyright Chimney Safety Institute of America

Chimney Fire Safety

Chimney Fire

Chimney Fire Safety

Keep the Fire You Want from Starting One You Don’t

Chimney fires don’t have to happen. Here are some ways to avoid them:

  • Have your chimney inspected annually by a Certified Master Sweep and cleaned when necessary.
  • Use seasoned woods only (dryness is more important than hard wood versus soft wood considerations)
  • Build smaller, hotter fires that burn more completely and produce less smoke.
  • Never burn cardboard boxes, wrapping paper, trash or Christmas trees; these can spark a chimney fire.
  • Install stovepipe thermometers to help monitor flue temperatures where wood stoves are in use, so you can adjust burning practices as needed to reduce creosote deposits.
  • Inspect and clean catalytic combustors on a regular basis, where applicable

What to Do if You Have a Chimney Fire:

If you realize a chimney fire is occurring, follow these steps:

  1. Get everyone out of the house, including yourself.
  2. Call the fire department.
  3. If you can do so without risk to yourself, these additional steps may help save your home. Remember, however, that homes are replaceable, lives are not:
    • Put a chimney fire extinguisher into the fireplace or wood stove.
    • Close the glass doors on the fireplace.
    • Close the inlets on the wood stove.
    • Use a garden hose to spray down the roof (never spray water directly on the chimney) so the fire won’t spread to the rest of the structure.

For more chimney safety tips, visit the Chimney Safety Institute of America or the EPA

Why do I need a chimney cap?

Chimney Cap



A chimney cap is a preventative maintenance measure to protect against water entry, backdrafts, and pest entry into the chimney. An uncapped chimney:

Says “come on in, make yourself at home!” to nesting birds and animals. Pests can, not only cause physical harm to humans (especially when surprised by you!), but they can also cause significant damage to your home. Their nests can block the flue, which can contribute to dangerous back-puffing, carbon monoxide poisoning, and chimney fires. No one wants their family exposed to that. Along with these dangers, animals nested in chimneys are noisy and can carry diseases so be sure to keep animals and birds outside where they belong!

Allows rain and snow to enter your chimney, which leads to moisture damage and expensive repairs.

Of any of the elements, water causes the greatest damage to your chimney. It soaks into porous bricks, eats away at the mortar, accelerates the deterioration of your chimney liner, and damages the mortar crown on the top of your chimney. A chimney cap does a great job of protecting your chimney from water damage. For maximum chimney protection we recommend a multi-flue cap. That’s because a multi-flue cap covers the entire chimney, not just one flue.

Creates a fire hazard as burning embers and sparks escape through the open chimney and land on your roof or in your yard.

Don’t Forget Your Clothes Dryer Vent

Clogged Dryer Vent

Don’t Forget Your Clothes Dryer Vent


The Chimney Safety Institute of America cautions the public that there’s a growing fire and carbon monoxide poisoning danger that could result in unnecessary deaths, injuries or property damage caused by the obstruction or improper venting of clothes dryer exhaust ducts.

To combat dryer fires and carbon monoxide poisoning, the CSIA recommends that homeowners have clothes dryer exhaust ducts professionally inspected annually — and maintained as necessary.

Dryer Locations: CSIA points out that clothes dryers have historically either been located in basements or on the main floor of a house and generally within a short distance from an outside wall. Because of these logistics, the danger of lint plugging the exhaust duct has been minimal.

But in today’s complex and technologically sophisticated homes, many clothes dryers could be located in the inner core of the house in bedrooms, bathrooms, kitchens and even in hall closets. These new locations mean dryers need to be vented longer distances and sometimes even with sharp turns and bends to accommodate the structure of the home. These complicated systems make exhaust ducts harder to reach and also create more places where lint can collect and pile up. Because lint is incredibly flammable it poses a fire risk.

Natural Gas : The availability of natural gas clothes dryers is another reason why dryer exhaust duct maintenance is necessary. If a gas clothes dryer is not properly vented, it can cause carbon monoxide to be forced back into the home and that can be deadly.

Obstructions: In addition to lint obstructions or improper venting, bird’s nests or rodents and bug infestations can also plug up a vent causing potential fire hazards and carbon monoxide poisonings. In winter months snowdrifts and ice build-up can be another obstruction that often goes unnoticed. Symptoms of a clogged clothes dryer exhaust duct include incomplete drying of clothes at normal temperatures and very hot dryer temperatures.

Recommendations: Regular inspection of this often overlooked area of the home is important. When we inspect a clothes dryer exhaust duct, we check to make sure there are no obstructions and that the installation is correct. We also verify that the correct type of vent is in use. For example, homes with plastic exhaust ducts can be upgraded to metal exhaust ducts.

For more information, see The Chimney Safety Institute of America.

Fire prevention

October is National Fire Prevention Month!

Use a fire screen when burning in your fireplace.
Photo courtesy of http://images.hayneedle.com/mgen/master:UMC289.jpg

As liability claims have skyrocketed, home owner’s insurance companies are becoming better resources for educating home owners about potential dangers around their homes. As the saying goes, an ounce of prevention is worth a pound of cure! In that spirit, Liberty Mutual recently posted an article to alert homeowners to efforts they can make in and around their home to reduce the risk of a home fire.

Here is a teaser list of reminders:

  • Keep anything that can burn at least three feet from your furnace or any other heating unit.
  • Maintain a three-foot kid-free zone around open fires and space heaters, and never use your oven to heat your home.
  • Turn off portable heaters when leaving the room or going to bed.
  • Have heating equipment and chimneys inspected and cleaned yearly.
  • Use a sturdy screen to stop fireplace embers from flying into the room.
  • Let ashes cool before putting them into a metal container a safe distance from your home.

Keep a 3 ft. area clear around your furnace, water heater, and other heating units.


Decorating:: Scary and Sweet

Halloween is right around the corner now. Have you done up your mantel yet?

Follow our Pinterest decorating page for great mantel decorating ideas for all seasons!


Photo and free printables at http://ceci-bean.blogspot.com/2013/09/printable-halloween-mantel.html

Photo courtesy of www.homesessive.com/

Or sweet?

Photo courtesy of http://itsthelittlethingsthatmakeahouseahome.blogspot.com/2010_10_01_archive.html

Photo (and other fun ideas) found at http://homewithkeki.blogspot.com/2013/10/halloween-mantel-ideas.html

Buy local

Photo source:: unknown

I’m sure you’ve heard by now of the many benefits of buying your produce and other goods locally, but did you know that purchasing firewood from even a couple of counties away can make a critical difference to the forests in your area? Listen to some great advice from the Chimney Safety Institute of America on where to buy your firewood this year and why you should buy local.

“The fact is that a growing number of pests threaten our forests, but only with the help of humans, who are often the unwitting accomplices in the spread of invasive tree pests.

DontMoveFirewood.org is a great resource for better understanding the threat posed by pests and the important role we can play in dramatically reducing the threat.

The bottom line is that the firewood you plan to burn should be local, which means it should come from your community. Ideally, it’s wood that was harvested within 10 miles of your fire site, but definitely no more than 50 miles away.

Burning local means you won’t be introducing a new pest to a new environment, possibly creating new infestations with the potential to ruin healthy forests…The National Firewood Association can help you locate a reliable, local firewood seller.”

Where does your firewood stockpile come from? Do you know any local firewood providers that you would recommend to our fellow readers?

-See more at Wood-you-please-buy-local/

An inside look

Under certain circumstances a chimney sweep will recommend a Level 2 Chimney Inspection. Because there is additional time and equipment (and so cost) required some home owners are hesitant to purchase this important service.

In the video below Ashley Eldridge, CSIA Director of Education, shows us just what exactly a video scan shows a chimney professional. In a minute and a half you’ll see why your chimney professional should recommend this level of inspection for your chimney and why you should say yes!

CSIA video blog #1: Cameras make for more thorough chimney inspections from Chimney Safety on Vimeo.

The National Fire Protection Association (NFPA)’s 211 (Standard for Chimneys, Fireplaces, Vents and Solid Fuel Burning Appliances) states that a Level 2 inspection is required when any changes are made to the system. Changes can include a change in the fuel type, changes to the shape of, or material in, the flue (i.e. relining), or the replacement or addition of an appliance of a dissimilar type, input rating or efficiency. Additionally, a Level 2 inspection is required upon the sale or transfer of a property or after an operation malfunction or external event that is likely to have caused damage to the chimney. Building fires, chimney fires, seismic events as well as weather events are all indicators that this level of inspection is warranted.
A Level 2 inspection includes everything in a Level 1 inspection, plus the accessible portions of the chimney exterior and interior including attics, crawl spaces and basements. It will address proper clearances from combustibles in accessible locations. A Level 2 inspection shall also include a visual inspection by video scanning or other means in order to examine the internal surfaces and joints of all flue liners incorporated within the chimney. No removal or destruction of permanently attached portions of the chimney or building structure or finish shall be required by a Level 2 inspection.

Chimney Safety Week – Fireplace Safety

Info made available by: “Fireplace and Home Fire Safety” US Fire Administration and FEMA, October 22, 2012. Web November 29, 2012. www.usfa.fema.gov/citizens/home_fire_prev/heating/fireplace.shtm

Heating fires account for 36% of residential home fires in rural areas every year. Often these fires are due to creosote buildup in chimneys and stovepipes. All home heating systems require regular maintenance to function safely and efficiently.

The U.S. Fire Administration (USFA) encourages you to practice the following fire safety steps to keep those home fires safely burning. Remember, fire safety is your personal responsibility …Fire Stops With You!

“Fireplace and Home Fire Safety” presented by FEMA

Keep Fireplaces and Wood Stoves Clean

  • Have your chimney or wood stove inspected and cleaned annually by a certified chimney specialist.
  • Clear the area around the hearth of debris, decorations and flammable materials.
  • Leave glass doors open while burning a fire. Leaving the doors open ensures that the fire receives enough air to ensure complete combustion and keeps creosote from building up in the chimney.
  • Close glass doors when the fire is out to keep air from the chimney opening from getting into the room. Most glass fireplace doors have a metal mesh screen which should be closed when the glass doors are open. This mesh screen helps keep embers from getting out of the fireplace area.
  • Always use a metal mesh screen with fireplaces that do not have a glass fireplace door.
  • Install stovepipe thermometers to help monitor flue temperatures.
  • Keep air inlets on wood stoves open, and never restrict air supply to fireplaces. Otherwise you may cause creosote buildup that could lead to a chimney fire.
  • Use fire-resistant materials on walls around wood stoves.

Safely Burn Fuels

  • Never use flammable liquids to start a fire.
  • Use only seasoned hardwood. Soft, moist wood accelerates creosote buildup. In pellet stoves, burn only dry, seasoned wood pellets.
  • Build small fires that burn completely and produce less smoke.
  • Never burn cardboard boxes, trash or debris in your fireplace or wood stove.
  • When building a fire, place logs at the rear of the fireplace on an adequate supporting grate.
  • Never leave a fire in the fireplace unattended. Extinguish the fire before going to bed or leaving the house.
  • Allow ashes to cool before disposing of them. Place ashes in a tightly covered metal container and keep the ash container at least 10 feet away from your home and any other nearby buildings. Never empty the ash directly into a trash can. Douse and saturate the ashes with water.

Protect the Outside of Your Home

  • Stack firewood outdoors at least 30 feet away from your home.
  • Keep the roof clear of leaves, pine needles and other debris.
  • Cover the chimney with a mesh screen spark arrester.
  • Remove branches hanging above the chimney, flues or vents.

Protect the Inside of Your Home

  • Install smoke alarms on every level of your home and inside and outside of sleeping areas. Test them monthly and change the batteries at least once a year. Consider installing the new long life smoke alarms.
  • Provide proper venting systems for all heating equipment.
  • Extend all vent pipes at least three feet above the roof.

How to Properly Extinguish a Fire

Here is a video produced by FEMA that explains how to safely extinguish a fire in your fireplace. Please excuse the ads this website uses before each video. (if the link does not work, please copy and paste into your browser http://www.monkeysee.com/play/16544-how-to-properly-extinguish-a-fire)