Sunday, February 9, 2020

Masonry chimney repairs should be done in the spring

By Marge Padgitt


Badly spalling bricks on a chimney
If there are pieces of bricks or stones lying around the yard or driveway, it could be a sign that masonry repair is needed. The first place to look for damages by cold, freezing rain, and wind is the chimney since it is the area most exposed to the elements.

Signs that repairs or rebuilding is needed are missing or deteriorating mortar joints, cracked bricks or stones, or faces of masonry popped off. This is due to the penetration of water into the masonry- and when water freezes it expands, which usually results in the face of a brick or stone breaking off.

Badly spalling bricks
Unfortunately, many chimneys are built with soft type bricks rather than hard type bricks due to the cost.  Soft bricks absorb moisture more easily than hard bricks. After a few years, the soft bricks will begin to show damage, but after 30 years any type of brick or stone chimney will likely show damages of some type, if only to the mortar joints.  In some cases, masons have found completely deteriorated bricks with hard mortar left behind. In other cases, the bricks are good but the mortar is severely deteriorated or missing altogether. When this occurs it is a sign that the wrong type of mortar was used.  For this reason, the Midwest Chimney Safety Council recommends that chimneys should be built or reconstructed using hard bricks and the right type of mortar which will last many years longer than those built with soft masonry units.

Mortar deteriorated so badly that
the chimney is falling apart
Mortar sets up better when the work is done in the spring when temperatures are moderate so the curing process can complete without issue. If the temperature is too cold, the mortar can crack and take a long time to cure. If the temperature is too hot the water in the mortar may migrate to surrounding masonry and shrink. Professional masons can control some of this by adding an accelerant in cold weather or soaking bricks in water before using them in hot weather, but they much prefer working with masonry in ideal weather conditions.

Cement cap with drip edge
The cement cap (crown) should be inspected in the spring to assure that it is in good condition with no cracks, deterioration, or lifting. The cap serves as a roof for the chimney and keeps the elements out of the interior chimney chase where rain can cause damage to the interior flue, smoke chamber, damper, and firebox. Any small cracks or gaps should be filled with high temp silicone, but if large cracks, severe deterioration, or missing sections of the cap exist a new cap should be constructed.  As of 2012, the International Residential Code required a poured formed crown with a drip edge to better protect the chimney from damaging rainwater. The old-style crowns with a slope but without a drip edge actually contribute to the fast deterioration of masonry at the top part of the chimney, so this newer style is a big improvement.
________________________________________

Marge Padgitt is the CEO of HearthMasters, Inc. and HearthMasters Education in Kansas City, Missouri. Contact her at hearthmastersboss@gmail.com

Wednesday, January 22, 2020

Maintaining Your Masonry Heater

By Marge Padgitt

Masonry heaters require regular maintenance in order to function properly, and the flue should be swept to avoid chimney fires. Maintenance includes sweeping of the chimney flue, brushing out the flue gas channels, an inspection of the chimney and heater, and doing any repairs necessary. If the masonry heater is operated properly there should be little, if any creosote in the flue, and you should find only small amounts of soot. If there is any amount of creosote in the flue proper operation and burning procedures should be reviewed. One to two very hot fires should be burned each day, or once every 12 hours for most heaters. The fire should not be “damped down” to maintain a longer burning time as is the normal procedure with a wood stove. The maximum number of fires per day should be three. For chimneys with exterior exposure, the flue will be colder than an interior chimney and will accumulate more soot.

Cleaning the flue gas channels involves using a small poly brush and vacuum. Go to the small channel doors, open them and clean and vacuum each one to remove fly ash. The chimney interior and exterior need to be inspected, and the heater itself should be inspected for any deterioration or loose firebrick in the firebox, any cracking in the exterior heater skin or finish work, and correct clearances to combustibles. Like any masonry structure, the masonry heater and chimney will need to be maintained and repaired as needed. Get a copy of the Homeowners Safety Manual and Burning Guide for Masonry Heaters for free at www.mha-net.org.

Be sure not to use a grate inside the firebox. Fires should be built right on the firebrick floor. The door should be closed during operation, and flammable liquids should not be used to start fires. Homeowners should not burn anything other than dry cordwood in the heater. Building a top-down burn fire will provide a clean burn startup with less CO and smoke. The top-down burn is the opposite of what you learned as a Scout. Place a couple of large logs on the bottom with an airspace between them, then add smaller logs on top in the opposite direction, then kindling. Try Fatwood or dry pine as a fire-starter. The fire will burn down slowly, like a candle. This method warms the flue slowly and causes draft to establish before the fire really gets going.

Your professional chimney sweep is best qualified to sweep and maintain a masonry heater, and can likely do any minor masonry repairs needed as well. Find a professional chimney sweep at the Chimney Safety Institute of America site at www.csia.org.

For more information visit www.mha-net.org or call Executive Director Richard Smith at 530-883-0191.
_______________________________
Marge Padgitt is an industry veteran, author, and educator. 

Clogged gas flue can cause illness or death

On May 17, 2016 Blue Springs, Missouri homeowners Richard and Mary Buckley were told by their heating and cooling contractor that they needed to call a professional chimney sweep to inspect their chimney. High carbon monoxide readings indicated that something was wrong with the venting system.


When a chimney sweep arrived he found an unlined chimney in a 100-year-old home that was completely blocked with four feet of mortar, debris, leaves and twigs. The gas boiler and gas water heater could not vent toxic carbon monoxide gasses out of the flue, and it had been that way for years. The chimney sweep speculates that the only reason the homeowners were still alive is that the house is old and drafty, and that outside air diluted the toxic gasses coming into the home.
Unfortunately, the homeowners did have some symptoms of CO poisoning, which consisted of flu-like symptoms while they were inside the home, but ceased when they left the premises. This is common when a house is toxic.

According to the Midwest Chimney Safety Council, gas flues are often ignored and neglected and are commonly in much worse condition than fireplace flues. People tend to think about removing flammable creosote from a wood stove or fireplace flue, but don’t often realize that the condition of a gas flue is critical. While gas does not produce creosote, it does produce Carbon Monoxide, which must be contained within the flue walls until it exits the chimney at the top.
If the chimney is damaged or does not have a flue liner, CO can leak into the interior structure. Blockages cause CO backup, and incorrect sizing of the flue liner or connecting pipes can also be a CO hazard. Most heating and cooling contractors do not service, maintain, or repair gas flues or chimneys, and refer chimney work to professional chimney sweeps.
HearthMasters urges homeowners to have their utility flue checked annually at the same time the fireplace is serviced by a professional chimney sweep. We recommend that homeowners use a sweep who is certified by the Chimney Safety Institute of America. 
_________________
Marge Padgitt is the owner of HearthMasters, Inc. chimney and fireplace restoration and educational school in Kansas City, Missouri. www.chimkc.com