Renovation & Design
Renovation & Design
Quality furnace filters boost indoor air quality
Question: I am seeing lots of ads for duct leaning. I never know if this is a procedure that is needed or not. We installed a high efficiency furnace five years ago and I am wondering if cleaning is required? What do you recommend? Dianne Z.
Answer: Duct cleaning should normally be done after a new home is built, or extensive renovations, to prevent fine construction dust from circulating through the home. As far as a regular maintenance service, it will probably not improve the indoor air quality, so is not recommended other than for the above stated conditions.
Regular cleaning of a home is a very important general maintenance task, often one that is reluctantly done rather than enjoyed. Regular cleaning, including vacuuming, washing floors, dusting furniture, and cleaning of plumbing fixtures in the kitchen and bathrooms, should be done on a frequent basis. This will certainly depend on the number of members in the household, time of year, weather, and numerous other factors. One of the major considerations for the need to clean is the presence of dust and other contaminants that may circulate through the air in the home. In homes where the occupants have no serious allergies, it may not be a big deal. In others, where family members may have respiratory problems, asthma, hay fever, or sensitivities to airborne particles, it can be a more necessary job to maintain good health. This may be especially important during the shoulder seasons, when windows are open for ventilation, and pollen and outdoor contaminants have easier access to the indoor air.
While cleaning is essential, one other regular maintenance chore should also be done to help prevent circulation of dirt, dust and pollen inside the living space. Frequent cleaning or changing of the furnace air filter system, and HRV filters if present, may be just as important. A good quality, pleated air filter can be the number one way to prevent airborne particles from blowing around the home. These should be removed, discarded, and replaced every one to three months, depending on several variables. If you have pets that regularly shed, more frequent changes will be in order. If you have an electronic or electrostatic filter system, that uses low voltage to help reduce airborne dust, its elements and filters will also need regular washing. If you have a cleanable type static air filter, throw it in the garbage and replace it with a disposable pleated filter. Once any air filter becomes dirty, it will eventually become clogged, and will no longer be as effective. It will also prevent good air circulation through the heating ducts and may even raise heating and cooling costs, slightly.
To help maintain good air filtration in your home, running the furnace blower on a continuous cycle is a good idea. Even when the heating or cooling cycles are not in use. That will provide continuous air movement, and constant filtration, with minimal extra costs. The small amount of electricity required annually for this will help much more, and cost much less, than a single duct cleaning. It may require more frequent filter changes, but seeing how much dirt and debris is caught in your filters will illustrate how well that system is working. More expensive filters, with a higher MERV rating, should trap more and smaller particles, but may not be worth the higher cost. However, if the home occupants have allergies, or are more sensitive to airborne contaminants, then the better filters may be worth the added expense.
So, why is it not a good idea to include regular heating/cooling duct cleaning in the regular maintenance routine? Because studies done several decades ago examined this issue and found that while duct cleaning does remove the built-up crap from inside these spaces, it really has little to no effect on indoor air quality. Keeping these hidden passageways free of dust and debris may make you feel better about your home hygiene, but in reality, it makes almost no difference to the air you breathe. That is likely because most of the debris collects in the return air ducts, due to low velocity of the airflow, rather than the heating ducts. The much higher air pressure in those ducts, which circulates the heated or cooled air from the HVAC system, is strong enough to blow most of the debris out of the metal cavities into the household air. The return air ducts will draw some of those contaminants all the way back to the furnace, but the majority may stay inside those low-pressure cavities. Either way, a good air filter will trap and collect most of those particles before they get to the furnace blower, and keep household air circulation to a minimum.
As you have stated, you see several adds for duct cleaning, but certainly many less than even a decade ago. That is because the mostly unnecessary service has declined in popularity, except after major renovations, new construction, or other forms of contamination have occurred. So, instead of hiring a duct cleaner, spending a little more on better quality air filters, and changing them more often, is a better course of action for improved indoor air quality in your home.
Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and a Registered Home Inspector (RHI)(cahpi.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at trainedeye.ca.
trainedeye@iname.com
Renovation & Design
Leaking rooftop pool cause for condo concern
Question: I purchased a brand-new condominium in 2020, near the ocean. The building is seven floors high, including the rooftop pool, and four condominium units wide. In the past six months I have noticed that one of the interior walls that is constructed of plaster over block has developed horizontal bowing, in places for a span of 20 feet or so. The wall in question is a dividing wall to another condominium, which also shows bowing, though not to the extreme mine does. We do have a rooftop pool two floors above that has been leaking into the condos below. Could leaking from the pool cause the drywall to bulge or could it be a structural defect?
Thanks,
Gina C.
Answer: Water leaking from anything on a flat rooftop, especially from a pool, could certainly cause big moisture related problems, even major structural damage. Engaging the condo board to immediately hire a consulting engineering firm, and talk to a lawyer about legal action, should be the next course of action to ensure this problem is properly rectified, and to prevent a possible catastrophe.
Of all the inquiries I have received, and hundreds of columns that I have written over the last couple of decades, yours may be the easiest to answer. The answer to your two-part question is yes and definitely, yes! As discussed here many times, water is the number one enemy of all things to do with buildings. Whether it is rain and snow roof leakage, moisture intrusion from windows and doors, or attic condensation, it will cause damage to many components inside and outside. This could certainly lead to deterioration of structural components, which could be the beginning of major failure. Anything of this magnitude, especially on a multi-story condominium like yours, could be a serious life safety threat.
Flat roof systems are very common on multi-family residential, commercial, and industrial buildings. These are designed to allow storage and easy access to various mechanical systems, like air conditioning condensers, which can be noisy and problematic when located elsewhere. Sticking them up on top of roof may require some modifications to prevent vibration and noise problems, but otherwise is a good location to get them away from the living space. Because of the very minimal slope of this type of roof, ponding precipitation and potential leakage is high. For this reason, flat roof systems have to be very high quality, durable, and long-lasting. Also, regular inspection and maintenance is required to prevent small breaches from becoming major issues. This will be necessary, at least on an annual basis for a typical flat roof, but may be much more enhanced due to the location of your rooftop pool.
With modern roofing systems and water-proofing membranes it is certainly possible to locate a recreational pool on top of a multi-story building. But even when done properly, there is still a much higher chance of moisture intrusion into the building from that area. Extensive testing and inspection should have been the next level of scrutiny, to determine the actual source of the leak. Then, a plan for remediation could have been designed, hopefully by a combination of a pool expert, flat roofing contractor, and professional engineers. If that was not done, continued leakage is a certainty.
Water leaking into the upper floors of a condominium like yours could certainly cause bowing and cosmetic damage to the drywall, but your wall issues may also be due to major structural damage. Without delay, you should notify all of the building occupants/owners, and the condo board, about the issue and insist upon urgent review of the situation by professional engineers, and other qualified individuals as needed.
Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and a Registered Home Inspector (RHI)(cahpi.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at trainedeye.ca.
trainedeye@iname.com
Renovation & Design
Vermiculite insulation likely not a concern as long as contained
Question: I recently had an insulation contractor come to my home to upgrade my attic insulation and ventilation, based on your recommendations from a previous inspection. I called you because there were moisture stains and cracks on my ceiling, which I thought were from and older roof leak, that has since been repaired. You noticed that the ceiling was sagging and recommended getting another layer of drywall installed to reinforce the damaged ceiling and prevent more sagging. That repair has been completed and the ceiling looks great
You also suggested that the ceiling damage may be partially due to moisture buildup in the attic and recommended additional insulation and ventilation. The contractor that I hired recently sent a crew to accomplish that task and they entered the attic from an opening they made in the roof. They were disappointed to find that I had some vermiculite insulation in the attic and stopped the work, immediately. They stated that they would not be able to do the job because their process of blowing in the additional insulation would be under pressure and could disturb the vermiculite. If it contained asbestos, which is likely, their work would cause it to be dislodged and would be a major health hazard. They closed up the roof and left. I think I can live without the additional attic insulation, but have other questions.
I am wondering how big a health concern this is for my home, currently, and if there is anything I should be doing to prevent my family from being exposed to the asbestos in the insulation? Do I have to tell any potential buyers about this when I sell the home, likely in the next few years.
Thanks for all your help and advice, Client.
Answer: Vermiculite insulation that contains asbestos is only a health hazard if it can get in to the living space in your home. Ensuring that your ceilings are in good shape, and any attic access hatches, or items protruding into the attic through the ceilings, are well air sealed should be enough to prevent any major safety concerns
One brand of vermiculite insulation, Zonolite, was found to contain a significant amount of asbestos, which may become airborne over time. When the insulation is disturbed, retro-fit mostly in homes in the 70’s and 80’s, the asbestos may become friable and enter the air surrounding the insulation. In that scenario, occupants of the building may be able to breath in the tiny fibres. Over several decades, significant exposure to asbestos may lead to major health issues and a specific type of cancer call Mesothelioma. Until they discovered that Zonolite, made from minerals extracted from a specific mine in Montana, contained asbestos this was not an issue in residential properties. Since that time, recommendations from agencies like Health Canada were to leave it alone and prevent disturbing it, because it was primarily located in attics.
The location of the vermiculite inside a home is critical in understanding the potential health issue it presents. In some homes it was poured or placed inside exterior walls, around chimneys and fireplaces, or other areas where air leakage may occur. In those situations, some of the small, shiny, silvery chunks may become loose and fall into the living space. Exposure to those areas by the home occupants could be hazardous as any asbestos fibres may become friable and airborne at that time. If the vermiculite is only in the attic, there may be no access points for it to enter the living space, making the safety concern negligible.
Because of a phenomenon called the stack effect, written about in many previous columns, air movement inside a building is primarily upward. Because warm, heated air will rise within a structure, air movement is almost always from the living space to the upper floors, and potentially the attic. Because of this, it is highly unlikely that any friable asbestos released by vermiculite inside an attic will make its way into the air of the living space of a home. The exception to this may be anything that penetrates the upper floor ceiling and is not properly sealed. The biggest culprit is almost always the attic hatch, which may be loose, poorly insulated, or even have gaps around the perimeter. Any of these could allow small particles to fall into the area below the hatch, especially if the cover is removed for any reason. The second largest problem areas may be any bathroom exhaust fans that are ceiling mounted and extend up inside the attic. Especially if they were installed long after the home was built. These may be poorly sealed or have gaps around the fan housing, where vermiculite particles and asbestos fibres could potentially enter the bathroom below.
When selling your home, you should disclose the presence of vermiculite and that you did not have it tested to see if it contained asbestos. Any potential buyers may request this be done, hopefully at their expense. Many older homes in our area have the same issue and it is not advisable to remove the vermiculite, which could put the living space at a higher risk of exposure than leaving it be. The main preventative action you can take to avoid contamination of your home and occupants is to inspect all the upper ceiling areas and seal any of these potential problem areas. Using weatherstripping, caulking, blow-in foam from a can, or conventional 6MIL polyethylene air/vapour barriers to seal the hatch and other areas is important. The difficulty may be to get any contractors to enter an attic with vermiculite, should air sealing from above be required. Anyone doing these tasks must take proper precautions for their own safety, and to prevent contamination of the living space below the hatch and any areas being sealed. This should include wearing disposable coveralls and gloves, respirators, and enclosing all work areas with polyethylene sheathing.
Ensuring that the entire attic floor, essentially the upper floor ceilings, are well sealed may be the only item required for your home. As long as the vermiculite insulation in your attic cannot enter the living space, there should be no physical threat to the health and safety of the occupants.
Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and a Registered Home Inspector (RHI)(cahpi.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at trainedeye.ca.
trainedeye@iname.com
