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Up in Smoke

Up in Smoke

Article written by Jack Carr, P.E., R.S., LEED AP, Criterium Engineers
Published in Condo Media, May, 2015 

If you asked the typical condo unit owner what is the most dangerous appliance or element in their unit, not many would think of the heating unit and its venting system.  This venting system includes the chimney in its many forms and associated fireplaces or wood stoves either sharing multiple-flue chimneys or direct venting.  This heating system is dangerous not only from the obvious fire hazards but also the potential exhaust leaks allowing carbon monoxide gas into the unit and the wasted fuel costs from inefficient combustion.  Yet even with these potential dangers, when was the time the issue of maintaining this potential hazardous unit element was brought up at a board or general meeting?

 Fortunately, many Maine condo’s are built today with clean burning fuels such as natural gas.  But Maine has a reputation of having more wood burning heating units than anywhere in the country.  Even the EPA and other concerned agencies have been warning Maine home owners of the dangers of air pollution and the lack of fire protection.  The alarming rates of Maine building fires these past two winters has only fed these fears resulting in an increase in related scams such as gypsy chimney sweep contractors.  These unscrupulous contractors pose as certified chimney inspectors offering super instantaneous discounts for re-lining; inspecting; or sweeping chimneys.  Their work often results in serious problem causing for expensive repairs.

 To clear the smoke of the mysteries of chimney maintenance, I will be providing some basic facts about the matter.  First of all, similar to Maine’s general contractors and home inspectors, the state of Maine does not license or certify chimney sweeps.  There are no Maine chimney sweep guilds or organizations providing certification.  So when service providers suggest they are certified by Maine, be wary.  Some states do certify chimney sweeps.  There is even a Massachusetts Chimney Sweep Guild.  But not in Maine.  The better chimney sweeps in Maine will often become certified under the national Chimney Safety Institute of American or National Chimney Sweep Guild.

 Though chimney sweeps and the National Fire Protection Association (NFPA) will recommend masonry chimneys be inspected yearly, in reality, the way a chimney is used will dictate how often it should be inspected and/ or cleaned.  Masonry chimneys venting wood burning fireplaces will need much more maintenance than propane gas fireplaces.  Wood fireplaces or stoves running ‘slow cool burns’ will produce more creosote deposits on the flue walls than hot burning fires.  It is this creosote build-up that often causes chimney fires.  Chimneys rarely used, such as in vacation homes or owned by ‘snow birds’, should be inspected before being lit off after a long vacancy as they can be unexpectedly clogged with bird nests; bats; and a whole list of critters.

 In developing a condominium chimney maintenance plan, a review of NFPA 211 would be a good start.  This publication defines three types of recommended chimney inspections as Level 1, Level 2, and Level 3.  A Level 1 inspection is the most basic visual inspection used when the heating appliance is in use and will be used as it has been in the past.  The inspection will cover the exterior, interior, and accessible portions of the appliance and the chimney connections.  This will include the verification of no obstructions or unacceptable combustion deposits.

 A Level 2 inspection is also a visual inspection recommended whenever changes are made to the use or configuration of the heating appliance or venting system.  This includes changes in fuel types; changes to the flue liner; and introduction of a new heating unit.  This level of inspection should be used prior to a building sale or after a serious event potentially causing damage to the chimney such as a chimney fire; seismic event; building fire; or serious weather event.

 A Level 3 inspection is needed when a search for hidden hazards is required with for special tools for invasive investigations.  This may require the removal of permanent chimney components to gain access or to investigate concealed conditions.  This is obviously a more intense inspection incorporating both Level 1 and 2 criteria.

 In addition to visual inspection some chimney sweep firms offer video inspections allowing real-time examination of the flue lining for cracks or mortar spalling.  These types of inspections not only produce a written report but also photographic evidence of the actual condition of the chimney’s internals.  Also make sure the chimney cap is inspected.

 Initial chimney inspections can also bring to light code violations and other problems.  In general, any chimney found to be unlined should be lined either with stainless steel vent piping or cement grout.  Chimney flues found to be venting both wood and fuel oil exhaust gases should be corrected to allow only wood or fuel oil, never both.  Condo complexes can take advantage of economies of scale.  Chimney sweeps often offer good discounts for performing inspections when 10 or more units are to be inspected.

 As indicated earlier, gas fireplaces and heating units usually create a cleaner exhaust and therefore fewer problems with chimney deposits.  But gas, either natural or propane, has its own safety risks.  Not only from the potential of carbon monoxide gas but if distribution piping and valveing are damaged or installed improperly the potential explosive consequences can be very serious.  These systems also require inspection by qualified technicians.  Even tank filling protocols are important.  If a propane tank serves more than one building, always fully fill the tank not just enough to serve the occupied units.