How to air seal and insulate your loft so your house does not lose all of the warmth it needs to keep you warm this winter. Getting your attic up-to-speed with insulation is one of the most cost effect measures to help your home be more energy efficient.
Going to the attic usually means one of three things.
1. Your 10 years old and playing hide-and-seek.
2. Your 32 years old and you have one more valuable heirloom to keep away for ever.
3. Your 54 years old and you’ve noticed a wet spot on the ceiling and you are afraid the roof is leaking.
These are all good reasons to enter the loft, but for now, let us enter the attic to look at the insulation and determine if adding more insulation would be a good – house warming – lower the power bill – thing to do.
Building codes effecting insulation levels didn’t actually start to take affect until the early 1980’s. If your home was built prior to 1984, there is a pretty good chance that your attic has minimal attic insulation. Builders in the 1940’s did not insulate much of anything, builders in the 1960’s filled the space between the roof rafters with about 4 inches of insulation. Builders in the 1990’s installed 8 inches ( R-25 to R-30 ) of loose-fill fiberglass insulation and by the year 2000, insulation levels had reached 12 inches ( R-38 ). Today, based on the homes location, attics are being insulated with 16 inches of blown-in fiberglass ( R-49 ), cellulose, or shredded blue jeans.
Yes, shredded blue jeans, I’m serious, the ripped up blue jeans were being installed in a wall as insulation.
Attic insulation is energy efficient if you live in a cold climate and you are trying to keep the heat in and the cold out, or if you live in a warm climate and you’re trying to keep the cold in and the warm outside.
Dark colored, metal fiber appearing insulation is probably rock wool. A popular attic insulation in the 50’s and 60’s. Fairly powerful and not a health hazard. However, insulation granules that are roughly 1/4 inch square that feel like Styrofoam and contrast from mirror shiny to dark in colour may be vermiculite asbestos. This is bad stuff due to the asbestos content. Don’t handle or disturb this insulation without the direction of a professional contractor.
Tip – Do not mess with knob and tube wiring and do not handle vermiculite. Call a pro.
If your home was constructed before 1940, you want to be aware of knob and tube wiring. This can be clothed bound wiring that’s attached to ceramic knobs as it runs over wood framing structures or runs through ceramic tubes when the cable runs through holes in the framing or building material. This type of wiring will have to be replaced by new electrical wiring by an electrician prior to insulating. If you insulate directly over knob and tube wiring, the cable can heat up and make a fire danger.
One more thing, watch where you step when in the attic, only step on the truss or rafter framing lumber. If you measure between the framing members you’re likely to stick your leg through the ceiling and have one ugly hole to spot and one heck of a mess to clean up until the small women gets home.
Tip – to supply a place to put your feet while you work on sealing the attic floor, have a piece of plywood to the attic that will reach over several rafters.
Tools and materials needed:
1. Standard face mask and mild coveralls. Fabric or leather gloves and eye protection.
2. Drop light so that you can see what you are doing and where you are going.
Tip – miner style head lights work great here.
3. If you have a flue or chimney running up through your attic, or recessed lighting or ceiling fans, you will need a little roll of light weight metal flashing, 18 to 24 inches wide. One pair of tin shears.
5. Tube of cheap general purpose caulk and a caulk gun. In case you have gas appliances, also pick up a tube of high temperature caulk.
6. Cardboard port chutesfor placing between the roof trusses in precisely the same location as each eve vent or bird block. Count how many you’ll need by counting the amount of eve or soffit vents from outside the home. The easiest tool to put in the chutes is with a squeeze or tacker stapler.
7. Extra cardboard to use as obstacles to separate areas where you don’t want insulation.
The best way to prepare the attic prior to installing insulation:
1. Remove the items you have stored in the attic that have been placed over the heated area of your home where you are going to insulate. Items stored over the garage can stay. Boards which were set in the attic to store items on also need to be removed.
Tip – Have a garage sale.
2. Take the port chutes and the tacker stapler and put in a chute at each location where there’s an eve vent. Fit the chute so insulating material can’t block the port and a flow of air can move from the outside, through the eve port up through the chute and out to the loft. Attic ventilation is important for the health of your attic.
3. With bits cut from the roll of metal flashing and the high temperature caulk, seal around the flue pipe where the pipe comes through the ceiling. Cut a half circular pattern from the edge of the metal and install around the pipe like a collar, screw in place with the sheet metal screws by screwing through tabs wrapped up on the sides of the metal and screwing into the framing members of the truss. Caulk the space between the flashing and the pipe using the high temperature caulk.
Tip – when working with the thin metal, wear gloves to avoid getting cut from the metal.
4. Now take the metal flashing and the tin shears and form a cylinder around the flue pipes and masonry chimneys and anything else that conveys hot combustion gases. Use the sheet metal screws to hold in position. These cylinders should seem like extra tall turtle neck sweaters on a metal neck.
5. If you have recessed lighting or stained lights ( same thing), locate them in your loft. Older canned lights which you can’t cover with insulation won’t be IC rated. The IC rating should be clearly indicated on the label attached to the back of the light. Don’t confuse a UL rating ( Underwriters Laboratory ) using the IC rating. They are not the same thing. A UL rating means the canned light has a cutoff switch installed which will turn off the light if it gets too hot. An IC rating means it is safe to cover the canned light with insulating material. Air space between the IC rated light and insulation is not needed.
Tip – Today would be a good time to upgrade the recessed lights to sealed cans and IC rated.
If the canned light is IC rated, seal the light where it comes through the ceiling with overall purpose caulk – your ready to install insulation over the lighting.
If the canned light is not IC rated, seal the light in which it comes through the ceiling and some other holes in the light body with high temperature caulk. Form a cylinder with the metal flashing and place it around the light body like you would a flue pipe leaving a two inch air space. Hold it in place with the sheet metal screws. This should look like a gardener that places an open end bucket over his young tomato plants so they are protected from the cold. The plant is the can light and the bucket is the sheet metal.
6. Find any exhaust fans, there might be none, one or more. The fans need to have a ridged or flexable round duct running from the fan to an exhaust point that puts the exhausted air outside rather than in the loft. Use the all purpose caulk or the foam spray to seal the fan body in the ceiling. Be sure the duct is exhausting to an eve port or a roof peak vent. Support the duct with wire or plastic ties to make certain that the duct does not fall down with time. An exhaust fan has a one way flapper valve in the exhaust fan body before it attaches to the duct. Given the opportunity, inspect the flapper valve and be sure lint, dust, hair, moisture and gunk hasn’t left the valve stuck open or glued shut. The flapper valve is a back flow restrictor, keeping warm or cold air from coming back down the duct into your house.
Tip- Today would be a fantastic time to replaced older noisy exhaust fans. I recommend an exhaust fan rated at 100 cfm (cubic feet per minute ) or more and on the quiet side.
7. Now take the can of spray foam and apply foam to every hole where an electric wire, T.V. cable, or telephone cable enters or leaves the loft. There ought to be vent pipes running up from the loft floor and out the roof. Foam where the pipe comes through the loft floor.
8. Some homes, both older homes and newer, may have open spaces which run from the loft floor to the floor below. These are spaces that result from unneeded space at the end of cabinets or bathtubs. They maybe caused by irregular framing like a triangle formed where a closet meets a hallway that matches a bedroom door. These open chases have to be sealed with more than just insulation. Have a sheet of cardboard, cut it to fit over the opening, lay a bead of purpose caulk around the lip of the opening, then lay the cardboard on top the caulk and twist down with the sheet metal screws. Now you simply insulate over the cardboard.
Ready to Resist
Tools and Materials Needed.
1. Tape measured- for calculating the square footage in your loft and for marking cardboard strips with the depth of insulation you want to add.
2. Insulation – fiberglass is a glass product, cellulose is a paper product. Either one is great.
Hint – fiberglass is itchy, cellulose not so much.
3. Insulation blower – Large hardware and building stores will have a blower you can use if you buy the insulation from them. Don’t forget to call ahead and book the machine. The blower comes with about two miles of hose.
4. Utility knife – for cutting open the packages of insulation.
5. Attic access tent- This is a seldom new item for insulating over the attic access opening after you have insulated the remainder of the attic.
6. Small roll about 12 feet long.
7. Gate latch – two little gate latches for holding the access lid down.
Take the tape and measure the width and length of the loft space. This can usually be done from outside the house by walking around on the lawn rather than in the attic walking around on narrow trusses. Plug the numbers into a calculator with a multiplication sign between them and calculate how many square feet are in your attic.
Have a trip down to your favorite hardware store and head for the insulation department. Grab a package and read just how much insulation is in the package at a particular thickness or depth. The chart on the package will allow you to calculate the number of packages of insulation you’ll need if your attic is a lot of square feet and you want to add so much R-value. As an example, 1 package will cover 100 square feet at R-16, 56 square feet at R-30, and 32 sq feet at R-49.
Tip – buy a bundle or two extra, as soon as you get started blowing insulation you don’t want to stop to go get yet another bundle.
Load up the mill and the insulating material in the rear of the pickup and head home for a great, energy saving day.
Place the blower at a handy location. You’ll need to plug the machine into an electrical socket, feed it with bundles of insulating material, and run the hose from the machine to the loft. Tack up a couple of the cardboard thickness indicating strips that you made so you’ve got a target depth to target for. Spray the insulation from the hose in a sweeping movement that allows the insulation to fall in your loft floor like a nice light snow. Fill one section of attic to the intended depth before continuing on to the next section. Take care not to guide the flying insulation to the eve chutes or within the cylinder barriers.
Tip – If your attic has an electrical junction box or any other fixed item that will be tough to find once covered with 16 inches of insulating material, mark it’s location by writing on a piece of cardboard and stapling the sign over the item on a roof rafter with an arrow pointing the way.
Fill the entire attic with fine new insulation to an even thickness indicated by the cardboard thickness measuring strips placed effectively around the attic. As soon as you have all of the attic filled except just the area around the attic access opening, stop for a minute, take some cardboard, and install an insulation barrier around the opening. Now you can add insulation to the proper depth up to the opening.
Hint – Plan ahead so the hose and the blower hopper is not full of insulation when you’re finished and need to take the hose off the machine.
Hey, you’re almost done.
1. Spread the loft access tent over the opening.
2. Attach the 1/4 inch self adhering weatherstripping to the contact perimeter of the lid that fits into and covers the access opening.
3. Install the hatch latch clips, one on each side of the lid in such a manner that if the latch is fastened, it pulls down on the lid and compresses the weatherstripping so the lid is air tight.
4. Load up the extra bundles of insulation and the blower and return to the store.
There’s bound to be a light sprinkling of insulation under the access opening and around the region where the blower was found. Brooms do not work well on insulation in grass or carpet. Grab the vacuum cleaner and don’t stop until your sure you won’t have to sleep on the couch.
You will now receive the satisfaction of a lower power bill, a warmer feeling, less drafty home, and a furnace that doesn’t need to work so hard. Hope this article has been a help, please come back soon and hurry, I will not be leaving the light on for you…