Renovation & Design
Renovation & Design
MIKE HOLMES: Be smart about green shift in your home
I'M often asked how to green an older home -- how to improve its efficiency and make it more sustainable. If you are building a new home and building from the ground up, you can pretty much do whatever you want within your budget. But restoring an old home to high efficiency is more of a challenge.
Not everyone can or wants to tear down an old home and rebuild to new net-zero standards. There's beauty and heritage in an old home -- and they don't build them like they used to.
But old buildings lag behind today's performance standards.
They were built years ago, before the products, materials, technology and methods we use today were invented. They have aged -- they have cracks in walls, loose windows and doors -- and very likely have little insulation. All of that contributes to lost energy and air leakage.
Tearing down an existing old home and building new has the obvious advantage of letting you create a high-performance home, which is greener than what was there.
But we also have to factor in the waste created when we demolish homes. There is a lot of embodied energy in the house that exists and we should factor that in before we make a decision to tear a house down and start over. It would take decades to make up for the lost resources and embodied energy in a home that is demolished to make room for a new home.
I'm not sure if the reduced energy savings in the new home makes up for all that lost embodied energy. It might just be more environmentally friendly to work with the materials that already exist in the house, and improve its energy efficiency. It's certainly less wasteful to improve than to demolish and rebuild.
Sustainable building is durable -- it lasts a long time. Old houses are doing that because they've already lasted a long time. Let's take buildings that do exist, and green them up. Anything we are able to reuse is something we don't have to replace.
Another facet of sustainable building is high performance and energy efficiency.
Houses weren't built in the past with the environment in mind.
But how green can you go with an old home? How much can you reduce its environmental impact? The answer: a lot.
The first thing to do is to take care of the basement and the attic. They'll give you the most positive result, and are the easiest to access, assuming your basement isn't finished.
Cold air pushes warm air and it will come in at the lowest part of your house and push the hot air out through the roof. So you should finish your basement properly and create a thermal break to prevent cold air from getting in. It will also keep warm air from meeting cold, which leads to condensation.
You also should insulate your attic space above code and make sure there is good venting. You have to ensure the attic stays cold in the winter, and gets hot in the summer. It is not meant to be a conditioned zone.
I don't like recessed lights in an attic space as they give off too much heat and will warm your attic space in the winter. But, if you must have them, make sure you are using the right ones. They need to be in insulated boxes if they are in contact with insulation, with seals around them to prevent hot air from escaping into attic.
It's important that you stop air leakage around windows and doors and air movement between the conditioned and unconditioned spaces in your house. If you are tearing right back to studs, use closed cell spray foam and make sure there's a perfect seal on walls and between the living space and attic.
There are other things you can do:
-- Replace old windows with double glazed, low-e glass -- especially on the north and west sides of your home.
-- Add skylights to increase natural daylight and reduce need for artificial light.
-- Install low-flow fixtures and reduce your water use, reduce air conditioner use by using exterior awnings or strategic planting to shade your home.
-- Always use low-VOC products.
-- Use materials with recycled content or from rapidly renewable sources.
-- Most important, choose materials with long life spans, such as a metal roof over asphalt shingles or BluWood over regular timber.
-- If you've got a bigger budget, add geothermal solar panels and grey water reclamation systems. Any of those will pay you back over time.
What's really important is that we learn that buildings are not disposable. We need to start building with the future in mind. I want my house to outlast me. I want my sustainable house to leave a lasting impact, but not a big environmental footprint.
Catch Mike in his new series, Holmes Inspection, airing Thursdays at 8 p.m. ET/PT on HGTV. For more information, visit www.hgtv.ca.
For more information on home renovations, visit makeitright.ca.
Renovation & Design
ARI MARANTZ: Repair leaking roof before the snow flies
Question: Our house is a split-level built in the early 60s, with an open-beam ceiling over two-thirds of the house. Ice damming and leakage into the house has been a problem during winter since we acquired the house three years ago. Snow will melt even at -10 C, as the roof slope faces south. The only way to prevent this has been to keep the open beam part of the house clear of snow. We recently removed some soffits and plywood to look in along the underside of the roofing material. As we suspected, the insulation was pushed right up against the underside of the roofing plywood. There were no insulation stops as far as we could see by moving the insulation back with a stick. The open beam is 30-feet long so wouldn't be impossible to work one-by-twos between the insulation and plywood, then turn them on edge to create ventilation channels to the ridge vent. Is there an alternative to lowering all the ceilings in the house or building up the roof with two-by fours-on edge?
Could we add rigid insulation to the roof using two-by-four strapping laid flat and then cover the roof with metal roofing? We hope this would provide more separation of the roofing material from the warmth of the inside of the home. Of course, with metal, there would be no leakage inside the house even if some snow melts on sunny February days. Would we cover the insulation with Tyvec-type wrap or use roofing felt? We look forward to your advice even though it is a winter problem. Now is the time to look after roofing concerns as not much can be done at 20 below.
Thank you,
-- Bruce Williams
ANSWER: This may seem like a funny time of the year to be talking about ice damming and winter roof leakage issues, but is actually the ideal season to explore this issue. You have hit the nail on the head when you have said it is difficult to do this type of repair in the middle of a freezing cold winter. I will provide a couple of possible solutions and hopefully answer your questions.
Your problem with ice damming and leakage in an older home with a vaulted ceiling is quite common. In my experience, it has become a particularly large issue with homes as old as yours, mainly in the last decade. I am not sure why many of these homes experienced little leakage for many years, even with ongoing ice damming, and suddenly the problems become serious. Perhaps, when the roofing is replaced for the second or third time something is disturbed, or simply the older plaster and interior components have developed cracks, openings, or enough minor moisture damage to become problematic.
You are correct the main cause of this problem is warm air leakage into a poorly vented roof system, often with minimal insulation.
There are two particular approaches to dealing with a vaulted roof. The first is to maximize the insulation level while maintaining a vented air space above the insulation, normally a minimum of five centimetres. The idea is that the vented airspace will provide enough outside air to cool the underside of the roof sheathing to prevent melting of the snow, and thus minimize ice damming. Unfortunately, this approach rarely works over the long term, unless you have very large roof joists, and high-density insulation. Most homes like yours have fibreglass batts or wood shavings packed into this space, neither of which is good at restricting air intrusion. In some cases, this type of insulation will only slow down the movement of air, just enough for it to cool past the dew point, causing condensation within the insulation or on the underside of the roof sheathing. This can often be the largest source of leakage with this style of roof, when the frozen condensation melts and runs back inside the house.
A better and more modern approach is to ignore ventilation altogether, and insulate with material that eliminates air and heat intrusion into the cavity below the roof sheathing. This can be accomplished from the exterior with rigid extruded polystyrene insulation, as you suggest, but the thickness will have to be substantial and the current insulation inside the cavity may need to be removed.
The most successful remediation requires removal of the leaky fibreglass batts and replacement with insulation that has a reasonable air/vapour barrier rating. Dense pack cellulose may be the most cost effective and environmentally friendly material for this purpose but it'll will only work if there is enough thickness to restrict air movement. That may not be possible in many older roof systems such as yours.
A better approach is to fill the entire cavity with either extruded polystyrene sheets or high-density blown-in polyurethane foam.
Both of these materials have the quality of good resistance to air movement, have a high R-value, and are extremely moisture resistant. While blown-in foam may be the most effective choice due to the ease of installation and complete coverage capabilities, it is the more costly. Often, a combination of rigid insulation, sealed along the top and edges with several centimetres of blown-in polyurethane is the most economical choice. It will be more labour intensive to insulate with this combination method, but the cost savings in material may make up for the higher wages required.
Either way, the existing roofing and sheathing will have to be removed to access the cavity, so repairs may only be practical when the roofing is near the end of its life.
Metal roofing may be a good option for longevity, but the vented air space that you suggest, alone, will do little to stop air intrusion from the house, which may be as much a cause of the leakage as the ice damming.
No matter what your choice of insulation material, the current view of most building scientists is that stopping air leakage into the roof system will cure the problems of condensation and ice damming much better than traditional insulation and ventilation methods.
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 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
ARI MARANTZ: Cold-air return will boost basement heat
QUESTION: We have a 1,440-square-foot basement under a full two-storey home heated with a high-efficiency gas furnace. We have four warm air outlets in the basement with no cold air returns. A friend, who used to install furnaces, told me to cut a return in the cold air return to the furnace, near the floor. Is this a good idea and if so what size should the opening be? If not, what alternatives do I have? Do I really need a cold air return there to increase heat and efficiency in the basement?
Thanks for your time, Wayne Spittal
ANSWER: A lack of return air ducting and registers in basements is one of the most common issues I see in older homes. While some of the finished rec-rooms in these basements are fairly comfortable in the heating seasons, others are not and often have supplementary electric heaters installed. Installation of proper return air ducting and registers should make the area much more comfortable, especially with your newer high-efficiency furnace that should have a much more powerful fan than the older one it replaced.
Your friend has given you good advice about installation of return air for the basement, but I don't think you got the whole story. Either you misunderstood his recommendation, or he was giving you a simplified solution that may not be the best one possible. While installation of return air for the basement will improve the air flow to and from the furnace, cutting a hole in the return air plenum right near the furnace may not be adequate for the entire basement and may prevent proper return air movement in your home.
The proper method to achieve what you want is to install one or more ducts directly to the existing return air ducting or plenum. These should run to one or more locations near the basement floor, but farther away from the furnace. Also, installation of proper registers over the end of the ducts will prevent excess dirt and debris from entering the ducting. Installation of these ducts can be through an existing interior basement wall or other accessible area. These ducts should not be installed directly against an uninsulated foundation wall, or within an insulated wall, as condensation can create moisture-related problems.
Because of the size of your basement I would expect more than one return air would be prudent, but if the entire area is unfinished, one may do until further walls are constructed.
A modern forced-air heating system in a home has two main ducting systems, which allow good air circulation throughout the building. The warm air ducting is typically installed below the main floor and will terminate in registers near the exterior walls on the main and upper floors. This ducting is pressurized as warm air is blown past the heat exchanger on the furnace by the furnace fan, into the ducting. This heated air will enter individual rooms in the house through these registers and rise to the upper level of the rooms due to normal convective forces.
Once the furnace fan shuts down, this air will cool and settle toward the floor. The return air registers and ducts are installed to help collect this cool air and draw it back into the furnace housing, so that it can be heated and recirculated once the fan is reactivated. Without return air ducting, as in your basement, much of this cool air may not be drawn back to the furnace, resulting in stale or damp air in that area of the home.
By cutting a hole in the return air plenum right near the furnace, you may collect some of this cool air from the basement, but not from the right location. If you install return air ducting and registers at the opposite end of the basement from the furnace, you will then make the air movement more efficient. The cool air will be collected from the location where it is most susceptible to becoming stagnant, at the far end of the home from the furnace.
This increased air flow will also allow the existing heat registers in the basement to more easily replace the cool air with warm, heated air, further improving comfort.
I'm glad that you are seeking advice from a professional heating technician, even if he is no longer practising, but you should be careful about the application of that advice. While you may be adept enough to do some of the work in the installation of the new return air ducting in your home, this is normally a professional job. Holes in existing ducting and attachment of distribution pipes can be difficult to accomplish, unless you have the proper tools and know-how. A trained heating technician should also be able to do measurements and calculations, if necessary, to determine how many return air registers are required for your basement.
Warming up cool basements in the heating season is often something that many people desire but don't know how to accomplish. One of the simplest ways to achieve this goal can be to add proper return air ducting to this level of the home. Improving air circulation to the furnace, by this method, can be the difference between comfort and cold in your basement. Another benefit of improved airflow is to minimize stale air and prevent condensation and mould growth, common to basements with no return air systems.
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 e-mailed to the address below. Ari can be reached at (204) 291-5358 or check out his website at www.trainedeye.ca.
Renovation & Design
Out, damn'd spot
QUESTION: There is a fair bit of black spot on my roses, and I have lost the recipe for a baking soda spray to control the disease.
ANSWER: The baking soda spray, developed at Cornell University, helps to control the spread of both black spot and powdery mildew on roses. Remove infected leaves before spraying and apply the spray to both upper and under sides of the leaves, as well as the stems.
The original spray combines five ml (one teaspoon) each baking soda and horticultural oil in one litre of water. Shake the mixture well before and during the spraying.
Refinements to the spray include the addition of five ml insecticidal soap to help the solution adhere and cling longer to the plant. To foliar feed the plants and enhance their disease resistance, adding 10 ml of liquid seaweed fertilizer to the mix will be helpful.
Alternating the baking soda spray with a sulphur spray may help to increase the effectiveness of both. Apply sprays every 10 days as needed. Make sure the plants are well-watered before spraying them, and apply the spray in the evening, never during warm, sunny days.
-- Postmedia News
