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Before starting any renovation project, you should know how your house works. Only then will you be able to evaluate and protect your investment. A house works just like a well-balanced system: every modification has its repercussions. From an energy-efficiency point of view, the four principal elements are: air tightness, insulation, ventilation and heating. For example, if you insulate your house, you reduce drafts. This will affect the humidity level and heating of your house. Foul air with a high moisture content will no longer be able to leak out and this will promote new problems. Insulation, air tightness and house ventilation are all very important and must be taken into account before any kind of renovation work is undertaken. A homeowner who is aware of these notions can understand and solve most of the problems caused by heat or cold, window condensation, plaster cracks, mildew and in some cases, flaking paint.
You will see in this DVD all the necessary steps to insulate your house. You will also learn how to make your house airtight and finally, we will show you appropriate solutions to control the effects these renovations can have on the air quality inside your house.
Artaud Communicaitons presents: So You’re Renovating Insulation caulking and ventilation
The exterior walls of a house are responsible on average for 10 to 30% of all heat losses. It is possible to insulate the walls either from the outside or from the inside of the house. Insulation from the outside is more effective and always strongly recommended since it envelops the whole structure. The building and its wood structure is better protected from temperature extremes and is less prone to move around; cracks in plaster or wall-coverings will be less likely to happen. Indeed, the wood structure of the house won’t be exposed to frost during the wintertime and will be more stable. Since the structure is always warm, condensation and rot hazards are greatly reduced. Drafts can easily be sealed off, specially between the house’s different levels and rooms. You should always make sure not to use outside materials that would prevent the walls in your house from « breathing » properly. Dampness penetrating the walls gets trapped inside them and could make the whole house structure rot away. To insulate a wall from the inside, you must completely remove the plasterboard. Only then can you verify the state of the structure. With a knife, check out all traces of rotting and repair the damaged wood. All rotted wood must be eliminated ; rot is actually a type of fungus that can quickly proliferate. Mold growths are usually the result of condensation stemming from large interior air leaks that carry humidity right through the walls. When it comes in contact with the cold side of the wall, this humidity condenses and infects the timber.
First of all, the wall has to be repaired; all the holes must be sealed off using appropriate caulking material. When the structure has been cleaned and repaired, you can move on to insulating the designated area. To insulate the wall properly, you should look up your local building codes to achieve the necessary R-values. Insulation is measured in terms of thermal resistance. R is the value, RSI the value by international standards. The higher the R-value is, the more effective the insulation will be. In general, exterior walls should have a minimum thermal resistance of R20. The ceiling immediately under the roof: R32, the basement walls: R13, and the floors over an unheated area: R27. Fiberglass insulation has a thermal resistance value of approximately R3,2 for every one-inch-thick layer. This material is effective, economical and ideal for insulating areas between the wall studs and the sheathing. It is manufactured in a variety of sizes capable of fitting your stud-framed wall with 3,5 inches blankets of R12 for a 2 by 4 frame; of 6 inches of R20 for a 2 by 6 frame, and 10 inches of R32 for a 2 by 10 frame. To cut through the fiberglass, use a straight-edged board and a utility knife. Use the board to compress the insulation and cut through; you will obtain a neat and precise line. When handling fiberglass, always wear a long sleeves and trousers, gloves and protection goggles. Insulate the holes in between the structure beams without packing down the fiberglass too much. Fiberglass is effective because it keeps air out. If it is too much compressed, its R value decreases. Friction maintains fiberglass insulation in place. Make sure no cold air can circulate behind the insulation. This can sometimes happen when the insulation blanket is too wide.
Slide the insulation blankets as far as you can behind the pipes. For electrical wires, separate the insulation blankets as shown and overlap the obstacle with them. It is very important you take your time for this, as the insulation must be perfectly adjusted. The pieces should not be too small or too big. For holes where insulation is hard to apply, as is the case around windows for example, use polyurethane foam.
Shake the foam container well before use. The expandind foam is very efficient to seal and insulate small openings. It has a thermal resistance of R5 per inch. It can expand 3 times its original volume. Do not fill the gaps completely so the foam has room to expand, specially around door and windows. If you spay water on the foam, it will expand even more. You will be able to cut out excess foam when it dries.
If your stud-framed wall is built with 2\4 lumber, you should add 3-inch-thick fiberglass blankets between the wood studs to achieve an R-value of 12. If there is no exterior insulation, this will not be enough; R20 is the standard, meaning a 6-inch-thick fiberglass insulation. What’s more, you will have cold bridges. A cold bridge occurs when studs in contact with both exterior and interior walls conduct cold. In other words, heat is conducted outside by the 2/4 or the 2/6, both of which have a lesser thermal resistance, R1 for each one-inch-thick layer. To avoid cold bridges and get a minimum R-value of 20 in a 2/4 wall frame, you should ideally add 1,5-inch-thick rigid insulation boards inside or outside your home.
Extruded polystyrene is light and easy to install. For pipes or any other kind of obstacles, simply push on the prefabricated section to make an imprint, then cut with a knife. To cut a board, proceed as with the other fiberglass blankets. Use a framing square ruler, cut through the panel with a knife, and then break it. Rigid insulation boards have overlapping joints that increase airtightness. Determine where the half-timbered beams are and power-nail the panels with plastic-headed nails. Hinged casement windows can be sealed with acoustic sealant or polyurethane foam around the edges.
Finally, a vapor barrier must be installed. A vapor barrier is usually a 6 millimeter-thick polyethylene sheet. To have a continuous vapor barrier with little or no joints, install sheets that are as wide as possible. Staple the polyethylene vapor barrier across the entire wall, along the edges of the ceiling, and allow the plastic to extend 6 inches all around to be sealed off later on with acoustic sealant. Acoustic sealant is a flexible type of caulk that works perfectly for this kind of job. Using the caulk, draw 2 lines, one of them sinuous. This will produce very good airtightness and, because of the self-adhesive nature of the caulk, you won’t have to use any more staples. The vapor barrier must always be installed on the inner, warm side of the insulation. Its purpose is important and it must be perfectly airtight.
The vapor barrier blocks off all air drafts. It prevents moisture-laden air from passing through and lodging itself in the cold side of the wall frame. In time, this could result in decreased value of the insulation and may promote condensation problems and a serious outbreak of dry rot in the house framing.
Once the vapor barrier is in place, cut out window frames, doors and other obstacles, and then seal off the contours with acoustic sealant. Make sure everything is airtight. In the long run, a small air leak can bring in a surprising amount of humidity. Plastic boxes are available for electrical plugs, light switches and ceiling light fixtures. They will complete the vapor barrier. Ease the electrical wires into a previously cutout hole. Slide the box inside the vapor barrier. Seal off the hole, connect and install the outlet box, and seal off the contours. To perform any electrical tasks, we strongly recommend you seek out the help of a professional electrician. Don’t forget to attach the vapor barrier to the ground. Draw a joint with the acoustic sealant between the floor and the wall, then fold back the polyethylene. You’ll be able to cut off the extra polyethylene once the wall covering is installed. For the ceiling, install 6-inch-thick fiberglass blankets between the joists. Complete the vapor barrier using acoustic sealant and pre-cut strips of polyethylene.
If the vapor barrier is accidentally ripped of damage, you can fix it by using plastic tape specially design for this purpose.
This type of tape is very efficient and can replace the acoustic scellant in most cases.
The attic is one of the most important places to insulate. First of all, a vapor barrier must be installed if there isn’t already one. To do so, apply acoustic sealant on the joists sides and glue polyethylene strips. Make sure everything is properly sealed off. Leave the joist tops uncovered to let the wood « breathe ». Install rigid insulation boards between the joists and make sure its does not obstruct the airflow in eaves vents. Always leave a two-inch gap between the roof and the insulation to promote sufficient ventilation. Then, seal off all gaps where the ceiling and the dividing walls join, and openings around pipes, vents or wiring running across the attic. Since the plumbing backbone always moves around because of thermal expansion, create a polyethylene casing with acoustic sealant. Insulate between the joists by installing fiberglass blankets. Make sure the ceiling light fixtures protruding into the attic meet security standards, as is the case for this one, to prevent fire hazards. If not, proceed as you would for a chimney, and leave a space at least 2 inches wide between the insulation and the chimney or other any heat source.
The attic generally requires a minimum insulation R-value of 32, in other words, a 10-inch-thick layer of fiberglass. If you were not able to install 10-inch-thick blankets, you can add another layer over the bottom one at right angles.
Another possible alternative is to lay loose-fill mineral insulation. A loose-fill mineral insulation offers a R3,4 insulating value per one-inch-thick layer. It is easily poured into the attic and fills out all nooks and corners. Loose insulation can be used by itself or can be poured on top of the existing insulation. Feel free to use the two types of insulation together. A loose-fill mineral insulation is easy to install. Use a rake to spread out the material. It is especially important to insulate areas on the outskirts of the roof and over exterior walls. Loose-fill insulation is particularly effective since it fits snugly into those hard to reach places. Make sure to put in a uniform level of insulation everywhere inside the attic.
The basement quick overview
Once again, it is preferable to insulate your basement from the outside. You will take this occasion to waterproof your foundations at the same time. Extruded polystyrene is a great material because it is water resistant. The main problem with insulation the basement from the outside is the need to excavate. Note that it is possible to limit the excavation if you lay down the insulation panels this way.
If you need more information on insulating the basement, we recommend you look for the So You’re renovating DVD # 5 Finishing the basement
Draftproofing your home is the best way to seal off all those unwanted air leaks. Drafts account for 25% to 40% of your heating expenses, and can cause important structural damages to your home. Locate drafts by using an incense stick or a smoke horn. Close all the doors and windows and turn on all the fans that suck air outside, such as the drier, and the bathroom and kitchen fans, so as to create a negative pressure inside the house. The foul air will be replaced by fresh air which will make its way inside the house through all those unwanted gaps, making them all the more noticeable. Check areas close to doors and windows, electrical plugs, light switches and ceiling light fixtures. Check out other possible sources of drafts such as floorboards or baseboards. In the basement, check out all the doors and windows. Take special notice of the joint between the wall and the foundation called the joist header. Finally, check around the outlet box.
Once you have located all the drafts, they must be sealed off. For each specific surface, choose the appropriate draft excluder. Make sure all surfaces are clean and dry.
It is necessary to maintain constant pressure on the liquid draft seal trigger. Always keep the same angle and speed when applying. At the joint’s end, release the trigger and lift the handle to make a clean break. For sash windows, draftproof around the frame, and inside and outside the case. To draftproof under moldings, it is better to remove them completely. To fill up cracks larger than one quarter of an inch, use a lump of paper or a piece of insulation foam. This can help you save on draftproofing material. To smooth out the joint, dip your finger in a 50% water, 50% dishwasher soap solution. Put the molding back in when the job is done. You can also use insulating tape. Apply the tape on the molding, draw the joint and simply remove the tape. Once you are done with the draftproofing, use the cut-off end as a cork. If the area that needs draftproofing around the window is too large, you can use polyethylene strips sealed with acoustic sealant. You can proceed the same way to make outlet boxes in your walls or ceilings airtight, if you do not wish to use plastic boxes specifically designed for this purpose. Once again, pay careful attention to the joist header. It’s the joint in the basement between the foundation wall and the house wall. This is often a poorly insulated area where drafts abound. Polyurethane foam is one kind of draft excluder you can use here. Push the applicator in as deep as possible and apply the foam. You’ll be able to take the surplus off once the foam has hardened. Doors and windows might need a compressible weather-strip. In some cases, existing weather-strips are replaceable. There are many kinds of weather-strips: a V-strip or a spring, depending on where you plan to install them. Your retailer has several kinds of strips that will suit your specific needs. For doors and windows you don’t use a lot, choose reusable tubular plastic strips that you can easily remove without leaving any marks. Draftproof the solarium door, the basement windows or the small hatch leading to your attic. If in spite of all those improvements, drafts are still sweeping through your home, if your doors and windows are still very cold or misted up, you should think about replacing them altogether and opt for energy-efficient doors and windows.
Once your home is completely airtight and insulated, air gets trapped inside and is never renewed. This air is charged with humidity. An average family produces 10 to 50 liters of water per day through daily activities. All this humidity can damage your house’s structure: for example, misted up windows, rotting away frames, humidity spots, mildew and flaking paint all cause important comfort loss. The first thing to do is to reduce humidity sources by using the dryer, and bathroom and kitchen fans.
In the wintertime, try to maintain a relative humidity level varying between 20 and 40 percent, depending on the weather outside ; this way you’ll be able to avoid mist problems on your windows.
Although static ventilation systems such as eaves vents in the attic can help reduce condensation risks, they are usually designed for ventilating air that’s up in the attic, not inside your home. Wind-powered roof turbines can ventilate your house’s living spaces as long as they are equipped with ducts designed for this purpose. However, they offer no discharge control and do not recuperate heat. A good solution to these problems would be to install a mechanical ventilation system. A heat exchanger evacuates foul air and brings in fresh air from outside. It controls humidity excess, fights condensation and safeguards your house’s structure. A heat-exchanging ventilator is generally equipped with a hygrometer that controls the humidity level. It recuperates the heat through a polypropylene pocket that allows substantial energy savings. Fresh air from the outside is sucked in on one side of the fan and simultaneously heated up by the foul air that’s being extracted from inside, letting you save a lot on those heating expenses. What’s more, the heat exchanger continually ventilates the air inside the house, allowing a better heat distribution throughout the levels and offering a fresh, comfortable atmosphere.
It is quite easy to install an air exchanger. First locate where you will install the unit. It should be located in the basement, the garage or a closet. It should not be located in a place where it could freeze.
Install the air exchanger as close as possible to the exterior wall to minimize the length of the ducts but it should be at least six inches form the wall.
Screw the suspension chains to the ceiling joists and put the unit in place. Add springs to each chain to eliminate the vibrations coming form the unit.
Using the adaptor supplied, install the small drain on the unit. Now install the air intake. This air intake must be located as high as possible in the house since this will be where all the hot, humid and stale air will be easily collected. The air intake should not be installed next to a staircase.
If you install the air intake on a wall next to a closet, you will be able to run the ducts in that closet without any additional framing. You need to cut 8 inches holes in diameter to run the ducts. Connect the duct to the air intake. You can also install the control next to a closet so you can run the wire trough the closet.
Now install the exterior vents. You need to drive two 6 inches in a half holes through the exterior walls at a 6 feet distance from each other. This will prevent the stale air going out mixing with the fresh air going in.
Run the insulated duct and connect it to the exterior vent. Make sure the insulation envelops the duct all the way to the outside to prevent any condensation risks. Finally, screw the vent in place and caulk with the appropriate exterior scellant.
Back in the basement; install the fresh air distribution duct on the ceiling. Again, stay away from staircases. Install the distribution preferably in a large room where air can circulate.
Finally, you just need to connect all the ducts to the unit. For the insulated ducts, start by connecting the aluminum sheeting and then the insulation. Finish with the plastic envelop making sure the joint is airtight.
Using the color-coded wires, connect the unit to the control.
This air exchanger will help you control excess humidity in your house. It will increase your comfort, will help save energy and provide you with a better air quality all year round.
Improving your house to make it a safe and comfortable environment will surely bring about some expenses. However, you will be able to benefit from an enhanced quality of life all the while creating an increased resale value for your home. Moreover, energy efficiency will reduce your heating and air conditioning expenses and make your home a safe and comfortable living space. Finally, as it will cost less to renovate your home than to produce new energy sources, you will contribute to the protection of our environment and natural resources