Water leaks can cause corrosion, deterioration, dimensional damage, efflorescence, freeze-thaw spalling, staining, damage to interior finishes, and, ultimately, structural failure.
Common Chimney Problems in Aging & Historic Homes in the Cincinnati/ Northern Kentucky Market
Since at least the 1940s, the absence of a chimney liner in a chimney has been recognized as an imminent danger. Historic homes that reflect the architecture and charm of designs from our history have tremendous appeal, but with an old home comes an old chimney. In aging and historic homes, chimney problems are inevitable. This is a list of some of the most common problems associated with the chimneys in old and historic homes.
Dangers of Having No Chimney Liner
Fire safety experts continue to share a quote from that time period in which it was said that not having a chimney liner is hazardous at a near-criminal level.
In the 1950’s Chimney liners became mandatory in the U.S. Historic homes from the 1940s and earlier were usually built with no chimney liner, just bricks and not even fire bricks. These bricks are substandard for fireplaces and can create a lot of issues in a chimney. The following are the primary dangers associated with using any chimney that is not protected with a liner.
The Threat of a House Fire Due to Pyrolysis
A chimney liner protects against fire getting to combustibles which are not fuel (Like your house) When a fireplace is used without a flue liner or with a damaged liner, the exposed combustion materials go through a gradual process known as pyrolysis. As a result of pyrolysis, the structures are altered so that they combust at a much lower temperature. With no warning, a house fire will ignite and spread rapidly throughout the home.
Highly Combustible Creosote
Wood fires produce creosote, a highly flammable tar-like substance that is deposited into a chimney every time a fire is lit. If a burning ember floats up the chimney, it can cause the creosote to ignite. Chimney fires are always dangerous but especially when a chimney is not lined because virtually any chimney fire could easily spread throughout the home.
Bricks are durable, lasting a century or more if undamaged. Mortar, on the other hand, lasts only about 25 years at best. The mortar should be replaced whenever it begins to deteriorate because one of its primary functions is to protect the masonry system from moisture. If moisture intrusion occurs, winter cycles of freezing and thawing create movement in the bricks that break them down. A chimney will begin to lean and could even collapse when this occurs, though moisture can get in through other avenues besides damaged mortar as well.
Spalling is evidence of masonry damage. Spalling is when the front face of the brick pops off, and piles of debris around the chimney on the roof or the ground below provide evidence that the destructive process is occurring.
Exposure to Carbon Monoxide
Carbon monoxide is one of the byproducts of fires. Chimney liners keep this toxic combustible gases from fires contained in the chimney until they escape to the outdoors. In the absence of a chimney liner or with a broken one, these gases enter the residence. Carbon Monoxide is known as a silent killer because it is odorless, tasteless, invisible, and symptomless and escape from the deadly fumes is often impossible.
Normal settling of a house doesn’t necessarily cause foundation damage, but in older homes, there is a greater chance of damage caused by a shifting foundation due to the additional time. Cracks in the masonry is one of the symptoms of settling. When the cracks form, they begin to absorb water and then the water freezes and expands the cracks even larger.
TODAY• September 22, 2020
A massive fire that destroyed Rachael Ray’s New York home in August was started in the chimney, according to the celebrity chef. The sad news comes as a reminder to homeowners about the dangers of chimneys as fall begins and cold weather approaches.
Ray told “Entertainment Tonight” the fire started after the fireplace “burped,” causing the roof to catch on fire. The house in Lake Luzerne, about an hour north of Albany, was only 15 years old, she said, and they had the chimney cleaned twice a year.
“Basically the fireplace burped, and when it burped onto the roof, the roof lit, and just the way the day was and the weather, it just went up in kind of no time, but it burned for a long time,” she explained. “It caught again the next day for a short time.”
Russ Dimmitt, director of education for the Chimney Safety Institute of America, told TODAY that the “burp” Ray describes could have been caused by creosote — the deposits that are left in your chimney after you burn wood.
“If you have a chimney fire, what happens is that creosote is very flammable as it burns,” he explained. “It can burn so violently that it will actually shoot some creosote out top and it might land on the roof.”
Dimmitt said that with chimney fires like Ray’s, there’s lot of investigating to be done to determine the actual cause. But it does highlight the dangers associated with having a fireplace at home. Low section of couple resting by fireplace at home (Cavan Images / Getty Images)
According to data provided to TODAY by the National Fire Protection Association, fireplaces or chimneys were involved in an average of 16,030 fires per year from 2012-2016, with an average of 40 civilian deaths, 80 civilian injuries, and $256 million in direct property damage annually.
It’s scary to think about, but there are steps you can take right now to help prevent a chimney fire at your own home.
Have it professionally inspected and cleaned
The NFPA reports that the leading factor contributing to home heating fires is failure to clean the equipment. The organization recommends having your chimney inspected and cleaned every year by a qualified professional who can check to make sure it’s structurally sound and in good working order.
Make sure the wood you burn is dry
Man putting wood in fireplace (Johner Images / Getty Images)
Burning wet wood can create more flammable material deposits (creosote) on the inside of the chimney, Dimmitt explained. That’s why it’s important to make sure the wood you use is dry. “The ideal moisture content for wood to burn is between 15-25%,” he said. “If you just go cut wood, it’s going to be 50% moisture content or higher. So in order to dry that, you really have to split it.”
To split wood, cut it lengthwise so more surface area is exposed, and do so at least six months before you use it, he advised. Also, don’t put anything else in the fireplace except for wood.
“No Christmas trees,” Dimmitt said, adding that doing so can result in a massive house fire.
Make sure you have a chimney cap and take other precautions
Chimney caps are designed to keep animals out, said Dimmitt. “It’s possible (they’ll still come in), but they’ve got to really want to get in there,” he said.
Without a chimney cap, animals can nest inside. When you light a fire, the nesting material can ignite a chimney fire.
Other things you’ll want to ensure: Make sure there are no branches or trees within 15 feet of the top of your chimney, always keep your hearth area clean and void of combustibles, use a sturdy screen to prevent sparks from flying into the room, and never leave the fire unattended.
Know the indications of a chimney fire
“You might hear loud cracking or popping noises,” Dimmitt said. “There might be dense smoke coming out of your chimney. There might be a hot smell — everyone knows that hot smell, although we can’t really describe it.”
Gas fireplaces can also create problems
“It’s possible for someone to think, ‘Well, I don’t have wood so I don’t have a problem to worry about,’” Dimmitt said. “That’s actually not true.”
Your furnace or water heater could be vented into your chimney, and if the chimney is blocked for any reason, carbon monoxide could be coming into your home.
“With a gas burning appliance in particular you don’t have any smoke so you may not know you have a problem,” Dimmitt said. That’s why it’s important to have both carbon monoxide and smoke detectors in your home, he added.
Below is a list of the remedies used by Best Cincinnati Chimney to fix chimney liner issues that can lead to house fires.
- Flue Tiles – Used mostly for straight , short chimneys, this method of lining is used mostly on new construction. You generally cannot replace Terra cotta tiles but you can repair them.
- HeatShield® Cerfractory Flue Sealant Restores Your Chimney tiles– HeatShield® is a specially formulated “Cerfractory®” sealant material that restores the integrity of your chimney’s flue to vent hazardous flue gases from your home. It eliminates the dangers in your chimney caused by gaps, cracks and spalling for years to come. Best Cincinnati Chimney is a certified HeatSheild distributor. By using either the Joint Repair System or Resurfacing System, depending on the defects found, your chimney can be restored to its original peak level of safety and efficiency. View the HeatShield® manufacturer’s website.
- Stainless Steel Liners – This method of relining involves installing a round or oval stainless steel liner in the chimney. The liner can be either rigid or flexible; flexible liners are used for chimneys with offsets. Stainless steel liners are used mainly for woodstoves and oil furnace installations. Best Cincinnati Chimney offers UL Listed stainless steel lining systems that come with a manufacturer’s Lifetime Warranty.
- Aluminum – This method is similar to stainless steel, but the liner is made of aluminum. Aluminum liners do not tolerate the heat that stainless steel will. Aluminum liners can only be used to vent certain types of gas appliances. Note: Gas logs intended for installation in wood-burning fireplaces may not be vented with aluminum liners. We do not recommend, nor will we install aluminum liners in woodburning fireplaces or stoves.
WATER LEAKS IN MASONRY
At Best Cincinnati Chimney we know that durability of masonry depends primarily on its resistance to water penetration and water leaks. Water leaks can cause corrosion, deterioration, dimensional damage, efflorescence, freeze-thaw spalling, staining, damage to interior finishes, and, ultimately, structural failure.
It is well established that water will penetrate a masonry wall that is one unit thick. Even if built to every requirement masonry work can always leak. Material selection, the design itself and the quality of construction can all be factors in water resistance. Understanding the causes and mechanisms of water penetration in masonry will enable technicians to better diagnose and solve problems before severe damage occurs.
The main source of masonry water leaks is driving rains, and the level of penetration is affected by rain quantity and wind pressure. The directional consistency of wind-driven rains can create severe water damage to the affected side of an exposed masonry surface. Damage from wind-driven rain is most severe at the corners and top of a wall or chimney system because of changes in air flow patterns at these locations. Since wind speed and rainfall are such critical factors, a driving rain index for the United States was developed to illustrate climatic patterns. The driving rain index considers the average wind speed and rainfall for the country and creates zones on a scale of one to five, with ‘one’ indicating the least and ‘five’ the greatest exposure. Most severe water damage in masonry occurs in ranges three, four, and five due to frequent freeze-thaw cycles.
Once masonry walls are exposed to hours of driving rains, they usually reach a saturation point. Saturated walls will take from one to several days to lose most of this water. Trees, plants, and micro-organisms like algae can prevent it from drying. With cumulative cycles, a saturation point can be reached in masonry pores that often leads to leaks or damage to the wall system.
Water leaks can also be caused by condensation within the wall system itself. Chimney systems are especially vulnerable to condensation because water vapor is a large component of flue gases. Most of the water vapor escapes out the flue, but some will pass through tile liners and the mortar joints between the liners.
The greatest exposure to condensation occurs during the heating season as surface wetting and use of the system produce high humidity in the air cavities surrounding the liners. When the temperature of outer masonry walls of a chimney falls below the temperature of the air in the cavity, condensation often occurs on the inside walls. Masonry units can absorb up to .5 lbs of water from condensation; though masonry is relatively dense, it is also a porous material composed of a network of interconnected pores called capillaries that circulate water by means of suction. Capillary suction is an important factor for openings smaller than 0.5mm. Pores in clay brick generally have a diameter of about 0.01mm, while hairline cracks can range between 0.1mm to 1mm in width.
Water can enter a wall system through pores and cracks in the masonry units and the mortar joints, but very often water seeps through cracks or separations between the masonry and mortar. The water accumulates until it either penetrates to the interior, drains to flashings where it is redirected through weep holes, or simply evaporates through the exterior wall.
Although we try hard to solve water leaks, they can be very difficult to diagnose and even harder to stop. If you have a water leak going in, it may not be solved by the first attempt. Water leaks are not the fault of the last guy on the roof.
If you live in the Cincinnati, Ohio area, then you know how important it is to have heat in the long, cold winter. One way to stay warm this winter is with a fireplace. Although, having a fireplace does mean chimney cleaning and chimney maintenance. If you don’t have a chimney liner then you can also be at risk of other problems with your chimney. In this short guide, you will be informed when you should replace your fireplace liner.
- Older fireplaces
If you have an older fireplace and do not remember ever changing out the liner, it is most likely time to do so. Usually, a chimney sweep will inform you if you need a new liner if they have seen a buildup of residue from burning wood or any cracks to the liner. Chimney repairs can be costly and may not completely fix the problem, so if your chimney sweep has advised replacing the liner, you should heed his or her warning.
- If you have a cracked flue
If you have an older fireplace or even if you don’t, liners can get cracked or have other damage. It is more common in older fireplaces because the liners were built using clay or other types of materials rather than stainless steel, which is what the liners are made out of nowadays. If you choose to keep using a cracked chimney liner, the soot can dissolve into the mortar and the joints and cause a potential fire.
- Replace clay liners
If you have a clay liner that is not cracked or damaged, it is still wise to replace it. Over the years, the breakdown of the wood and charcoal into soot can clog the chimney causing a carbon monoxide leak. It is best to replace the liner if you can by purchasing a stainless steel or cast-in-place liner.
- Liner? What liner?!
You are probably not saving a lot of money if you have a fireplace without a chimney liner. Occasionally no liners were installed in the past, but it has been found that liners help the wallet! A stainless steel liner which is the industry standard requires less labor and are available in a variety of sizes to fit your fireplace. A liner will give you higher temperatures in the flue, which is a good thing because it keeps the soot to a minimum and saves on your heating bill.
- Hire a professional
Just as you would call for a professional to perform HVAC maintenance, power washing, roofing fixes, simple remodeling, cleaning of the gutters, or exterior painting, you want to do the same when dealing with chimney cleaning and chimney maintenance. This is especially true if you are not comfortable with the task or run into any obstacles. It is always better to call the professionals than to attempt a task and then regret it. Make sure to call a Cincinnati handyman if you get into a sooty situation!
As you can see, there are multiple reasons you should replace your liner. Chimney cleaning and chimney maintenance are critical to do yearly, as you do not want a carbon monoxide leak or a backup of soot into your home. If you follow our advice on when you should replace your fireplace liner, your Cincinnati home will be cozy warm this winter!