Renovation & Design
Renovation & Design
Vent blockage a common cold-climate problem
QUESTION: I enjoy reading your column and hope you can make a suggestion that will eliminate a problem I am having. I have two roof vent pipes installed on the north side of my home and they face the prevailing northeast winter winds. One pipe is closer to the edge of the home while the second is close to the peak. I increased the height last year and while it helped -- it only froze once last winter -- the pipes still froze solid during the coldest part of the winter. I increased the height as snow was piling up over the pipes.
I have to climb up on the roof, which is starting to get dangerous as I am 70 years old, and take a screwdriver and hammer to break open the ice and then pour hot water down the pipe. No one else seems to have this problem, or at least I have never seen anyone up on the roof during the winter. When the pipes freeze you get a sewer smell. I paid for a service call from a plumber in Steinbach and the fellow did not know what was causing it, but I still had to pay him for nothing.
Hope you can help,
Gary
ANSWER: Freezing or blockage of plumbing vent terminations above roofs is a fairly common problem in our area. This can be due to a number of factors, the most significant being our extremely cold winter weather. I will explain the reason for the location of these pipes, causes of your problems, and a couple of possible solutions.
The purpose of the rather strange practice of installing an open pipe just above the roof line in our homes is twofold. The first is to provide adequate air into the top of the plumbing drain system in our homes to ensure they don't block up due to air being trapped inside the pipes. While this is a fundamentally critical function, it may not be the most important.
The second reason for venting to the exterior of the house is to prevent sewer gas from leaking into our living space via the plumbing drains. Terminating these pipes above the roof ensures any vapours that potentially come up through the drains from the sewer will harmlessly be released outside rather than penetrate our indoor air.
To provide both of these functions, terminating the drain vent high up, above the roof, is necessary. Unfortunately, this location may be prone to blockage from snow, ice and debris such as leaves and roof litter.
The reason the top of these pipes normally will remain open and free of ice is due to the heat of the rising gasses from the drains. When hot water is run in any of the plumbing fixtures in the home, warm air will rise up through the vent pipes and normally melt any thin layer of snow or ice on top or prevent it from forming altogether.
The first key to preventing blockage with ice and snow is stopping partial blockage with leaves or debris. If the entire area at the top of the stack remains free and open, there is less chance of ice formation.
To prevent this hazard, inspection and cleaning the top of the vents in the late fall, after all the deciduous trees have lost their leaves, is fundamental.
Even with regular maintenance, icing over of low roof vents can occur. One possible solution is to do what you have; extend the vents higher up to prevent coverage with snow. While this may help prevent snow blockage, it may actually hinder the true solution to the issue.
The real cause of ice formation at the top of your vents is the loss of heat inside the pipe as it rises through your cold attic. If the pipe does not remain warm enough, the large amount of moisture in the air rising up toward the roof can condense and then freeze before it exits to the exterior. If you have older cast iron stacks, this is even more likely due to good conduction properties of the metal. An iron pipe will lose heat more rapidly than other ones, but even a more modern ABS plastic pipe can be subject to freezing.
The real key to preventing excessive heat loss and freezing of the wet air inside your stack is better insulation. Insulating the exterior of these pipes, mainly as they progress through your frigid attic space, may prevent this excess heat loss. While there may currently be a thin layer of fibreglass or other pipe wrap material around these stacks, it may provide only minimal help. Covering the stacks with better-quality or thicker layers of insulation may be the only thing required to prevent freezing.
Adding more insulation around the bases, where the vents enter the attic, can also prevent quick cooling. If you succeed in this regard, the ice and blockage problems may disappear.
In some homes, even better insulation inside the attic around the vents does not prevent blockage during the coldest weather. If your home is one of these exceptional units, due to location or other environmental abnormalities, further measures may be required. Installing a specialized heat trace cable outside of the pipe, embedded in the insulation surrounding it inside the attic, may be the final remedy. I would only recommend this as a last resort, as it may be tricky to install and somewhat costly to run.
While you have taken some measures to prevent snow blockage of your vents by extending them upward, that may not be the best solution since it's not effective in the coldest weather. Preventing excessive heat loss inside the attic with better insulation around these stacks should be the proper solution to your problem.
Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and president of the Canadian Association of Home & Property Inspectors -- Manitoba (www.cahpi.mb.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at www.trainedeye.ca.
trainedeye@iname.com
Renovation & Design
If car mats bunch up, replace them now
QUESTION: My car mats continually bunch up under my feet while I am driving. I push them down to flatten them but before I know it, they creep up into a bunch. Should I tape or glue them in place? If so what kind of tape works best? Helda (Virden)
ANSWER: Absolutely no tape Helda! When car mats are properly positioned they must lie flat. As much as I like to recycle, reduce and reuse; this is not the time. A car mat that bunches up under your brake is an accident waiting to happen. It is simply not safe because the car mat can potentially lock your brake in place preventing you from stopping. Please ask a reputable car dealer for advice on purchasing new car mats. In fact, motorists are wise to check that their mats lay flat every time they head onto the road.
QUESTION: I would like to decorate Christmas cookies without paying the hefty price of purchasing coloured sugar. Is it possible to make my own colored sugar? Andy, Winnipeg
ANSWER: Yes! Into a sealable bag or jar, pour 1 cup white sugar and add two drops food coloring. Shake or blend with a fork until sugar colours evenly, add additional food coloring to darken hue. Extra tip: The courser the sugar, the better it looks on cookies, cupcakes and cakes. Course sugar is available at Bulk Barn.
Feedback from readers:
Hi Reena,
In today's Winnipeg Free Press, Steph was asking how to get soft-centered cookies. I recently heard adding 1 tbsp. cornstarch to 11/2 cups flour works.
Concerning discoloured clothes washed in brown water: Some time ago I had this same problem with brown water coming into my white wash rinse cycle. I had success removing all the stains using Oxi-Clean. I used two scoops to one gallon hot water and soaked the items for six hours, then washed them in warm water. I only had to repeat the procedure for one 100 per cent cotton knit top. This may not work as well if the stained items have already been put through the dryer. Thanks for all your great hints.
Rosemary
I enjoy your questions and tips, keep them coming. Missed a column? Can't remember a solution? Need a speaker for an upcoming event? Check out my brand new videos/blog/website: reena.ca!
Renovation & Design
ASK THE INSPECTOR: Attic asbestos insulation best left alone
QUESTION: I live in a two- storey home in River Heights, built in 1965. The attic entrance is in a bedroom, which has been converted into an office and is used many hours of the day. I have no idea if there is asbestos in the insulation, but I was wondering if the air in the office could be tested for asbestos. The entrance to the attic is covered but not sealed, and no one has been in the attic for about five years.
Thank you very much for your help, and I enjoy your column in the Free Press.
Arthur Cohen
ANSWER: While I commend you on your proactive attitude toward testing for a potential health or safety hazard in your home, in this case, that may not be prudent. In most homes, any asbestos that may be hidden in your relatively well-sealed attic should be treated as in the old cliché: out of sight, out of mind. This may seem like an irresponsible recommendation for me to be making, but in relation to asbestos-containing insulation in attics, it is best left undisturbed.
In most Canadian homes there is only one type of insulation that was widely used that is known to contain significant amounts of asbestos. That insulation is a specific brand of vermiculite, which is made by heat expansion of a type of mineral, which is similar to mica. The brand that is known to contain asbestos fibres is Zonolite, manufactured from vermiculite ore that was previously mined at a site in Montana. While Zonolite was produced for many decades from this source, it was not until the 1980s that the presence of asbestos fibres was discovered or disclosed. By that time, thousands of homes in North America had vermiculite insulation installed. In most cases, this fireproof insulation was only installed by pouring the material from bags into attics. In rare cases, it was also poured into hollow wall cavities, but that was not very popular due to the difficulty in installation relative to other types of batt insulation.
The problem with Zonolite occurs when the material deteriorates over time. This is primarily a natural process due the composition of expanded vermiculite, which contains several types of compounds. When this deterioration occurs, some embedded compounds can be released, including asbestos fibres. One thing that significantly accelerates this rate of deterioration is disturbing, moving, crushing or stirring the vermiculite insulation. For this reason, the less an attic containing vermiculite is entered or worked in, the better. That is the main rationale for my earlier recommendation to leave well enough alone.
Because vermiculite was installed in many homes at a time when much lower insulation levels were considered adequate, numerous homeowners have added more thermal insulation in subsequent years. This newer insulation is normally composed of fibreglass batts, but also may include blown-in cellulose, loose fibreglass or other products. This newer insulation is almost always blown or laid directly on top of the older vermiculite, which has numerous benefits. First, the increased insulation may completely cover any exposed vermiculite, preventing deterioration from air movement or wind currents within the attic due to typical ventilation. Secondly, the weight of the new layers of insulation will significantly restrict movement of the vermiculite, preventing deterioration and asbestos-fibre friability. Finally, the newer blanket of material will help protect against damage or disturbance of the vermiculite should anyone enter or work in the attic.
Returning to your original question, testing the air in your office or home may yield no significant results, even if you have asbestos-containing Zonolite in your attic. Because nobody has opened or entered your attic for several years, there is almost no chance any asbestos has penetrated your living space. Any indoor air testing that is looking for asbestos will come out negative whether your attic is full of Zonolite or has none. The only true way of determining any potential risk is to remove the attic hatch, look to see if there is any visible or covered vermiculite, then collect a sample and send it to a laboratory for testing. To accomplish this, you will have to risk potential exposure of your office to asbestos contamination,where none currently exists.
It is true that other building materials in your home, such as vinyl flooring, cement boards, boiler pipe, forced-air duct wraps and even some finishing materials may contain asbestos. These are also of minimal concern if not damaged. Many of these products have fibres embedded well within other components, which may only be released when they are sanded, scraped, cut or otherwise manipulated during removal or renovation. The only major exceptions to this are asbestos coatings and wraps used on older boilers and heating pipes, which can become friable over time due to heat and deterioration. Due to the age of your home, it should not have an older hydronic heating system with asbestos on the pipes or boiler. For those that do fall into that category, they should be frequently inspecting the heating system so any loose or damaged insulation can be encapsulated to prevent release of fibres into the air.
The recommendation by Health Canada, CMHC and other knowledgeable authorities in relation to vermiculite installed in attics is to leave it alone. If it does have to be disturbed due to repairs or renovations, all possible precautions should be taken to prevent contamination of the living space with any loose asbestos fibres. As far as testing your indoor air for asbestos contamination, unless you have visible asbestos insulation on your hot-water heating system, there should be no need to test or worry.
Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and president of the Canadian Association of Home & Property Inspectors - Manitoba (www.cahpi.mb.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at www.trainedeye.ca.
trainedeye@iname.com
