This summer, Southern Alberta has seen extraordinary flooding, and shown extraordinary strength to match it. In the coming months, as we begin rebuilding and moving forward, the natural temptation is to do so as quickly as possible in an attempt to get back to a sense of normalcy. This is understandable, this is human, but it can lead to poor construction that can often be worse than the original conditions prior to the flooding.
When our homes have dried, and the clean-up work has been completed, where do we start? What questions should be asked, what techniques could help make my home more durable in a future disaster, and more energy efficient and sustainable now. This article will help to address some of these questions and act as a starting point.
I have been in, around and on top of Green Building in Alberta for more than 8 years as a designer, consultant and inspector on some of Alberta's most sustainable homes. As an instructor for R-2000 builders, and a LEED Canada for Homes Provider and Accredited Professional, draw from great experience, training and an excellent team of colleagues in tackling the challenges of building homes that are forward looking, durability and energy efficient.
My hope is that the following collection of advice and suggestions help you in looking beyond just our recent losses, and the challenges of rebuilding, but look towards a sustainable future where our homes are part of the solution, less at risk to disaster and more durable against the elements. This is general information only, each home and situation is different and readers must contact a professional contractor or designer consultant (like 4Elements) for specific and detailed information.
My recommendations are based on recent National Building Code recommendations and the LEED Canada for Homes program. As a guide for sustainable homes, LEED is a premier rating system for measuring sustainable, durable and energy efficient homes, it is considered the best reference for best practice.
Minor Damage: Basement flooding only
1: Basement w/ drywall removed (image from Concrobium.com)
Ideally, new insulation should be non-absorbent foam types, either type IV extruded polystyrene (XPS, sold often as dense pink or blue sheets of foam), or 2lb polyurethane spray foam. Using insulation like this in flood susceptible areas will simplify future clean up. These products offer great moisture protections, higher R-values per inch and do not absorb water. Most homes may only have R12 batt insulation, which effectively works at an R-value of 10 when framing is accounted for. Heat lost through the basement could be cut in half with the use of 4" of foam with an effective R-value of 21.
Spray foams can easily be installed around existing framing and directly onto existing concrete, once clean and dry.
- Spray foams should only be installed by qualified, certified technicians only. Surfaces must be contaminate-free and dry before application or the foam will fail.
- Flooding can cause structural damage so your foundation should be inspected by a qualified Engineer.
- Look ahead to upcoming code changes. R12 batt insulation for basements is no longer considered adequate, except in Alberta which tends to lag behind the rest of the country in our Building Codes. New National Building Code requirements are calling for insulation in basements to perform better than R20 batt insulation.
- Modern building science looks at basements differently than when your home was built and current recommendations for the Canadian climate call for added insulation, better air tightness, but no poly behind the drywall where its possible moisture could collect. Poly is too vapour tight, and often traps moisture behind, often causing damage. New products can be used such as "smart vapour barriers" or drywall with vapour barrier paint. These prevent most moisture movement, but do allow some drying when needed, preventing the "Double Vapour Barrier" issues that can cause problems.
Furnace and Hot Water Tanks:
If your furnace or hot water tank was damaged this may be a great opportunity to make one of the quickest pay back upgrades possible. Look for EnergySTAR ratings and condensing type equipment. These new units have sealed combustion; this means that gasses from the furnace or hot water tank can't leak backwards into the home. It is not recommended to replace a damaged boiler, hot water tank or furnace with the same chimney venting system that was likely original. These systems are the reason we install carbon monoxide detectors to prevent carbon dioxide poisoning deaths, which claim the lives of Albertans every year.
Air sealing for Health and Energy Efficiency:
New research from Health Canada (Link) has lowered the acceptable limits of Radon exposure. Recent sampling across Alberta has shown unacceptably high levels in ALL parts of the province. Radon is a natural occurring carcinogenic soil gas that occurs throughout the province. The Environmental Protection Agency in the US lists long term radon exposure as the 2nd leading cause of lung cancer in the States and we would expect similar findings in Canada, if not higher due to more common use of basements.
Basements are a major source of cold air leakage in homes and air leakage typically makes up the larger proportion of energy loss (aka your energy bill) of any other area of the home. The basement rim joist area where the floor framing meets the concrete is often a particularly leaky area. Surprisingly, the basement slab is a major source of air leakage where left unsealed at the slab edge or unsealed plumbing holes. This is from air finding a pathway through in the drainage gravel and weeping tile below the slabs and through sump pump covers.
Air sealing your basement will improve overall comfort by keeping the cold air from settling in the basement, reduce energy costs due to increase heat loss and improve indoor air quality. Better air tightness must always be tied good ventilation. The walls and ceiling of a home (the "envelope") can never be too tight, but many homes are under ventilated.
If your old appliances were damaged during the flood this may be a great time to replace and upgrade.
New Fridge: Getting rid of, or updating your basement "beer" fridge can make a noticeable difference in you power bill. Old fridges are notoriously inefficient. Look for EnergySTAR labels.
Washer and Dryer: Clothes Washers are large water users in typical homes often second only to Irrigation or toilet use. EnergySTAR washers use less water and energy if certified. EnergySTAR does rate dryers as well. Look for units with "Auto Dry" sensing so that clothes are less likely to be over dried, wasting energy.
Best in class appliances can be found at the NRCan web site:
EnergySTAR Listings-Best in Class
All EnergySTAR labeled appliances can be found at:
Carefully assess how your home and property responded to water and take appropriate actions.
- Sanitary sewer lines can be retrofitted with back flow preventers, now mandatory on many new homes.
- Improve surface water drainage away from home ensuring ground is higher next to homes foundation and slopes away on all sides.
- When rebuilding decks and exterior stairs ensure that wood to concrete connections are separated using metal to improve longevity of the wood.
- Using hard surface floorings in a home improve indoor air quality by not trapping dust and contaminates.
- Use non-paper based drywall for first 4' or more of basement. This type of drywall will better to be able to withstand water damage and if combined with non-absorbent insulation will likely not require removal in future floods.
- Properly installed, drained sump pump system. Consider a solar back up power system with small amount of battery storage. Generating free power in the good times and running the homes critical systems in troubled times.
New Alberta Building Code requirements are in place in flood prone areas, talk to your local building officials for detailed information.
Look for new products that are Low VOC and contain high percentages of recycled content. Make sure to prefer post-consumer recycled content rather than simple factory offcuts and similar which are considered pre-consumer recycled content.
FSC (Forest Stewardship Council) Wood:
Choosing FSC-certified products means choosing products that come from a sustainable and responsible source. For more information visit https://ca.fsc.org/index.htm
Whenever possible, choose local products. Locally produced products have less distance to travel, so they have a lower embodied energy.
Many times the added cost to "Go Green" over standard practices is minimal and in most cases should not run more that 10%. Consumers have to be aware of green washing of many products, if a product does not meet the thorough and stringent requirements of LEED, you should be suspicious. Also many trades may inflate prices when requests are made for unfamiliar products or techniques, look for experience on certified green building projects.
Here are some rough example costs:
Typical Basement Reno:..................$30 000 - 50 000+
Improved Insulation:....................Add $2000 - 4000
EnergySTAR Appliances:..................Add $0 - 500 each
Improved Hot Water Tank:................Add $300 - 1000
Improved Furnace:.......................Add $300 - 2000
Improved Air Tightness:.................Add $0 - 500
Major Damage: Reconstruction
If your home sustained heavy damage and required a gut renovation (walls opened up in all or most areas) there are even more opportunities to re-build better. Overall, the same recommendations apply, better insulation and air tightness, better ventilation will ensure that your new home will exceed current building practices and look ahead to a sustainable future for all Albertans.
LEED Canada for Homes:
In a full renovation, your home would be eligible for enrolment in the LEED Canada for Homes program, providing you with a clear guide to rebuilding a sustainable, durable, energy efficient home. A LEED for Homes Provider will be your point of contact, reference and guide through the program. Adding LEED certification can cost as little as $2000 in fees and inspections, with most often less than 10% added to the cost of construction. LEED has certified over 200 homes in Alberta and over 3000 in Canada. LEED is enforced and used by builders, municipalities and governments across Canada and recognized leader in sustainable building.
LEED Canada for Homes
LEED Canada for Homes Providers