Renovation & Design
Renovation & Design
ASK THE INSPECTOR: Fighting moisture in addition's curtain wall
QUESTION: I helped a friend put an addition on his house and to imitate the foundation of the original, he used piles with the floor cantilevered to accommodate a pressure-treated 2x6 wall built between the bottom of the floor and the gravel surrounding the house. Rigid insulation will be placed on the outside and buried on a downward sloping angle to offer drainage and reduce lateral frost penetration. This curtain wall was built with pressure-treated, half-inch-thick plywood on the outside, a layer of inch-and-a-half SM rigid insulation, the appropriate fibreglass insulation for the wall depth and then a six-millimetre vapour barrier tied into the moisture barrier that had been laid under the sand in the crawl space.
A few days after completion, somebody noticed vapour forming on the inside of the plastic and elected to cut out the vapour barrier to allow air circulation. It appeared the SM rigid insulation on the outside wasn't allowing any avenue for moisture to escape. This quick fix leaves me with the concern that at 40 below there will be condensing on the back side of the fibreglass insulation, not necessarily causing rot as it is all pressure-treated but more a potential mould issue.
This curtain wall was built as you would if you were doing one above grade, which brings up the question of whether extruded polystyrene insulation is a vapour barrier? In this application, with the possibility of moisture entering the crawl space from the ground, there is the possibility of a perpetual 'leaky condo' situation. Or it would have reached an equilibrium, dried out and remain fine?
Now I know the manufacturer of SM maintain that it isn't a vapour barrier, it is the sheathing and the slight discrepancies in the overlapping of the SM that allow moisture to get out. We will monitor the crawl space this winter and if need be take of the exterior panelling and redo it.
Given that the pressure-treated plywood is on the outside of the SM and the old theory of one-third of the insulation on the cold side of the vapour barrier, two-thirds on the warm side of the vapour barrier, I think it will have to be attended to.
If you have any suggestions as to where I could find literature on properly doing this system of insulating under a structure, it would be greatly appreciated.
-- James Campbell, email
ANSWER: While you appear to have an excellent grasp of the building-science aspects of insulation and air/vapour barrier installations in homes and crawl spaces, you have one improper statement that may be contributing to your confusion. Your false assertion is that SM insulation, or extruded polystyrene (XPS), is not an effective air/vapour barrier. This material is quite a good air/vapour barrier and is touted by the manufacturer as highly moisture-resistant. If properly sealed at the joints, it can often be installed without the need for polyethylene sheathing and offer adequate resistance to air and moisture intrusion. You may be thinking of expanded polystyrene, which is not an effective air/vapour barrier and requires use of poly for effective air and moisture control.
Because of this property, you are correct that installation of this rigid sheathing near the exterior of the knee-wall assembly will create a double air/vapour barrier with the interior applied poly. This may well be a problem with trapped moisture in this area and may lead to moisture problems and deterioration of the fibreglass batts installed behind it. Because this short wall is constructed of pressure-treated wood and sheathing, rot and mould may not be an immediate issue, but the trapped moisture may reduce the insulation properties of the wall assembly, over time.
The good news is that the real culprit is not the exterior-applied XPS insulation, but the interior fibreglass and poly air/vapour barrier. It was wise to cut this poly to let some of the visibly trapped moisture escape, but further moisture intrusion into this cavity from the heated crawl space is still likely. A better method for insulating and sealing this area is to remove the fibreglass insulation and poly and replace it with more foam insulation. This can be accomplished by cutting other layers of XPS to fit exactly between the studs and installing enough to provide a suitable R-value without the need for a poly air/vapour barrier. The other option is to replace the fibreglass with blown-in polyurethane foam insulation between the studs, ensuring the foam is the required thickness and density to provide adequate air resistance. Either of these superior methods will provide a moisture and air-resistant insulation that will prevent moisture intrusion into the wall assembly, which is the source of the potential problem in the first place.
In direct response to your last question, a large amount of information on several possible methods of XPS installation can be found on the Dow chemical site, which is the manufacturer of Styrofoam SM insulation. Other information may be found on the CMHC site or the Office of Energy Efficiency section of the Government of Canada website or by contacting these organizations by phone.
Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and the president of the Canadian Association of Home & Property Inspectors -- Manitoba (www.cahpi.mb.ca). Questions can be emailed or sent to: Ask The Inspector, P.O. Box 69021, #110-2025 Corydon Ave., Winnipeg, MB. R3P 2G9. Ari can be reached at (204) 291-5358 or check out his website at www.trainedeye.ca.
trainedeye@iname.com
Renovation & Design
SOLUTIONS: WD-40 puts the ZIP back in zippers
QUESTION: The zippers on my convertible boat top are very hard to zip. Is there something to put on them to make them easier to close? I have used soap but it just washes off. Thanks, Merv, Winnipeg
ANSWER: Let me give you a few options to loosen the zipper: Use a solid, waxy substance such as candle wax made for snow skis, or a crayon. Using a toothpick, work the lubricant into the teeth of the zipper, and then slide the zipper up and down. In my opinion the most effective option is to spray the zipper with WD-40, wipe off excess and ZIP!
ZIPPER TRIVIA: Whitcomb L. Judson, a Chicago mechanical engineer, invented the zipper. It came about because a friend with a stiff back could not do up his shoes. Judson designed a slide fastener that could be opened or closed with one hand. In 1893 he patented a device called the "clasp locker," which was the forerunner of the modern zipper. It had only two problems: it didn't work and no one wanted to buy it. Judson displayed it at the 1893 Chicago World's Fair. Although around 20 million people went to the fair, he sold only 20 of the hook less fasteners. The U.S. Postal Service bought them to put on their mailbags. Instead of giving up, Judson founded the Universal Fastener Company to manufacture his new device. When a customer ordered a huge quantity of them for the rubber galoshes he was manufacturing, he liked the "z-z-zip" sound they made and coined the name zipper.
QUESTION: We are in desperate need of your help. Last week I fried cod fillets on the stove. Since then the odour of fish seems to permeate our house especially when you enter the house from outside. I have tried washing the floors and counters with vinegar and water. As well as leaving the doors and windows open for long periods of time. I have even purchased some sort of sponge container from our local Wal-Mart that is supposed to clean smells. Nothing seems to help. Any suggestions would be greatly appreciated. I have cooked fish before but never had this result. Thank you for your column and look forward to your insight. Linda, Winnipeg
ANSWER: Overpower the fish scent by bringing a pot of water to a boil, and squeeze in the juice and rinds from three lemons. Boil for 30 minutes, or until your fish smell is completely gone. You can also toss cloves, cinnamon, or nutmeg into your brew and boil those as well.
QUESTION: In which book is the solution you mentioned about getting rid of aphids with bananas? I have a huge linden tree in my backyard and it seems every summer everything is black because of them. Also, in which book would I find the solution for cleaning the interior of the shower? No matter which product I buy it doesn't seem to really clean. Thank you for your assistance. Always read your column. Margaret, Winnipeg
ANSWER: You can refer to Household Solutions 2 for your aphid challenge. Bananas are great for small inside plants but for a big beautiful linden you will need a larger quantity. In a 1 gallon milk jug, combine 2 tbsp. dish soap, 1 tbsp. rubbing alcohol, dash of Tabasco sauce, 1 tbsp. canola oil and enough water to fill the jug. Pour mixture into spray bottle and apply as needed (double recipe as needed). Another option is to steep cigarette tobacco in water. Leave for two days and spray the tree.
Household Solutions 3 with Green Alternatives has an entire section devoted to cleaning shower interiors. One of my favourite options is to pour 1 tbsp. baking soda, 1 tsp. dish soap and enough water to fill an 18 oz. spray bottle. Spray, leave for 20 minutes and wipe.
QUESTION: What kind of flower is Dianthus, I have seen it listed as a perennial and as a hardy annual? Megan, (Emerson, MB)
ANSWER: Dave, the Dianthus commonly called 'Sweet William' is an annual as are some others that are called 'Dianthus'. However, many varieties of Dianthus are perennials. So you need to identify exactly which Dianthus you are wanting to plant.
Feedback from readers:
Hello Reena,
In your Winnipeg Free Press column you mentioned that Tang (orange crystals) is okay to use as a cleaner for dishwashers. I would like more information about how to use it. Should it be dissolved or just sprinkled directly into the washer? Thank-you for your interesting and helpful information. Donna, Winnipeg
Donna,
You are not the only person requesting clarification on the subject of using Tang in dishwashers. Since orange crystals contain high amounts of citric acid it makes a great cleaner for the interior of commercial dishwashers. Once a month fill the detergent dispenser of the dishwasher with 2-3 tbsp. Tang. The dishwasher may be either full of dishes or empty. Run the dishwasher as normal. The purpose of using Tang in the dishwasher is two-fold, first it cleans out the hoses behind the dishwasher and secondly it cleans the interior of the dishwasher. Please note that this process will not zap rust stains in dishwashers.
Fabulous Tips of the Week:
* To protect your plants from cutworms, cut out the bottom of a margarine container and press it into the dirt around your plants.
* Plant mint between cabbages to discourage pests.
* Place large rocks next to garden pepper plants, the sun will warm the rocks and attract heat toward the plants.
I enjoy your questions and tips, keep them coming! Check out my web site! www.householdsolutions.org
Renovation & Design
ASK THE INSPECTOR: Geothermal heating costly, but does pay off
QUESTION: I have a question with regards to geothermal heating.
With the price of electricity and natural gas doing nothing but increasing, I am seriously considering installing geothermal heating. At present, I run a natural gas forced-air furnace that heats my Winnipeg home of about 1,500 square feet.
Next summer, my wife and I will begin landscaping the backyard and I figured why not kill two birds with one stone and get the plumbing in the ground for the heating system. My question is: How deep do I have to go with my piping and how many feet of pipe does an average geothermal system require?
-- George Anthonisen, e-mail
ANSWER: Geothermal heating and cooling systems are getting much attention these days, especially with the growing desire by homeowners and various levels of government to reduce energy consumption in our homes. The answer to your question is completely dependent on several factors in the installation of a geothermal heating/cooling system in your home.
I will describe some of these and other general issues and benefits of this type of system.
Geothermal heating and cooling is a very energy-efficient system that relies on the consistent temperature of the earth, deep below the surface, to provide both winter heat and summer cooling using a heat pump. Without getting into the complicated scientific principles that make this possible, the benefit of this system is significantly reduced HVAC costs for homeowners. The drawback of this system is that many metres of underground piping must be installed, making initial installation costs quite high. Once the system is in place, the lower cost of operation will more than compensate for this factor, but it will take several years to recoup the initial investment. For this reason, I commend you on your progressive attitude in this initiative and for seeking advice prior to commencement of any work.
Many of the early geothermal HVAC systems installed in our area were in rural locations, for a variety of reasons. The main consideration in several of these areas was poor access to natural gas supplies. Natural gas was, historically, a less costly energy source for heating our homes, especially with the advent of high-efficiency furnaces. Electric heating was often accomplished in these areas with electric baseboards, limiting air movement in homes due to the lack of ducting and fans associated with forced air. Humidity issues are more common with this type of heating supply, and electrical energy costs are higher than with comparable gas furnaces. Because of this, many of the current local companies that pioneered geothermal systems were based in rural communities.
The first and most important fact to consider in replacing your existing forced-air heating system with a geothermal one is the size and location of your home and the lot it sits on. To effectively and efficiently install a system of this type, sufficient land must be available to allow for proper heat transfer through the piping from the earth. Although your home is an average size, you may require an above-average-size lot to accomplish this. If you are located in an area where the lots are small and homes closely constructed, you may have to drill far too deep into the soil to get the proper surface area of piping necessary. The alternative is to install many more, shorter and shallower sections of piping, which may take up too large an area under your yard to be practical.
Other factors include restrictions caused by underground services like hydro, water, sewer and natural gas that may prohibit installation of underground piping. Underground water and soil quality may also limit the practicality of this type of system in an urban setting. Check with your local planning office for more information.
You have the right idea in planning for possible upgrades of this type prior to landscaping improvements around your home, but installation of underground piping for this purpose is not something that should be done by amateurs. Requirements are very specific and strict controls are in place to prevent environmental damage from coolant leakage due to improper installation. This type of work should only be done by a licensed HVAC contractor well-versed and trained in geothermal heating systems.
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 or sent to: Ask The Inspector, P.O. Box 69021, #110-2025 Corydon Ave., Winnipeg, MB. R3P 2G9. Ari can be reached at (204) 291-5358 or check out his website at www.trainedeye.ca.
trainedeye@iname.com
