How to Prepare and Insulate Your Own Attic
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 enjoying hide-and-seek.
2. Your 32 years old and you have one more precious heirloom to store away for ever.
3. Your 54 years old and you’ve noticed a wet spot on the ceiling and you are afraid that the roof is leaking.
These are all good reasons to enter the loft, but for today, let’s enter the attic to check at the insulating material and determine if adding more insulation will be a good – home warming – lower the energy bill – thing to do.
Building codes effecting insulation levels did not really begin to take affect until the early 1980’s. If your home was built prior to 1984, there is a fairly good chance your attic has minimum attic insulation. Builders from 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, depending on the homes place, attics are being insulated with 16 inches of blown-in fiberglass ( R-49 ), cellulose, or stained blue jeans.
Yes, shredded blue jeans, I am serious, the ripped up blue jeans were being set up in a wall as insulation.
Attic insulation is energy efficient if you live in a cold climate and you’re trying to keep the warm in and the cold out, or if you reside in a warm climate and you are trying to keep the cold in and the warm outside.
Dark colored, metal fiber seeming insulation is probably rock wool. A favorite loft insulation in the 50’s and 60’s. Fairly powerful and not a health hazard. However, insulation granules which are roughly 1/4 inch square that feel like Styrofoam and comparison from mirror shiny to dark in color might be vermiculite asbestos. This is bad stuff because of the asbestos content. Don’t handle or disturb this insulation without the direction of a professional contractor.
Tip – Don’t mess with knob and tube wiring and don’t handle vermiculite. Call a pro.
If your home was built before 1940, you want to be aware of knob and tube wiring. This can be clothed bound wiring that is attached to ceramic knobs since it runs over wood framing runs or structures through ceramic tubes once 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 create a fire danger.
One more thing, watch where you step when in the loft, just step on the truss or rafter framing lumber. If you measure between the framing members you are going to stick your leg through the ceiling and have one ugly hole to patch and one heck of a mess to clean up until the small women gets home.
Tip – to provide a place to put your feet while you work on sealing the attic floor, take a sheet of plywood into the attic which will reach over several rafters.
1. Standard face mask and mild coveralls.
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. For those who have a flue or chimney running up through your attic, or recessed lighting or ceiling fans, you’ll need a little roll of light weight metal flashing, 18 to 24 inches wide. 1 pair of tin shears.
5. Tube of cheap general purpose caulk and a caulk gun. In case you have gas appliances, also get a tube of high temperature caulk.
6. Cardboard port chutesfor putting between the roof trusses at precisely the same location as each eve vent or bird block. Count how many you will need by counting the number of eve or soffit vents from outside the home. The simplest tool to put in the chutes is using a squeeze or tacker stapler.
7. Extra cardboard to use as barriers to different areas where you don’t want insulation.
8. 1/4 inch, #6 sheetmetal screws and a cordless drill.
The best way to prepare the attic prior to installing insulation:
1. Remove the items you have stored in the loft which have been placed within the heated area of your home where you’re going to insulate. Boards that have been set in the attic to store items on also have to be removed.
2. Take the vent chutes and the tacker stapler and install a chute at every location where there is an eve vent. Fit the chute so insulating material can not block the port and a stream of air is able to move from the outside, through the eve vent up through the chute and out into the loft. Attic ventilation is very important to the health of your loft.
3. Cut a half circular pattern in 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 faces of the metal and screwing to the framing members of the truss. Caulk the space between the flashing and the pipe with the high temperature caulk.
Tip – if working with the thin metal, wear gloves to avoid getting cut by the metal.
4. There should be a two inch air space between the hot flue and the new sheet metal insulation barrier. Use the sheet metal screws to hold in place. These cylinders should seem like extra tall turtle neck sweaters onto a metal neck.
5. If you have recessed lighting or canned lights ( same thing), find them in your loft. Older canned lights that you can’t cover with insulation will not be IC rated. IC stands for Insulated Ceiling. 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 score. They are not the exact same thing. A UL rating means the canned light has a cutoff switch installed that will turn the light off if it becomes too hot. An IC rating means it is secure to cover the canned mild with insulating material. Air distance between the IC rated light and insulation is not needed.
Tip – Today would be a great time to upgrade the recessed lighting to sealed cans and IC rated.
If the canned light is IC rated, seal the light in which it comes through the ceiling with general purpose caulk – your ready to install insulation over the lighting.
If the canned light isn’t IC rated, seal the light where 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 put it around the light body just 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 which puts an open end bucket over his young tomato plants so they are protected from the cold. The plant is that the can light and the bucket is the sheet metal.
6. Locate any exhaust fans, there could be none, one or more. The fans should have a ridged or flexable round duct running from the fan to an exhaust point that puts the exhausted air outside and not in the attic. Use the all purpose caulk or the foam spray to seal the fan body at the ceiling. Be sure the duct is exhausting to an eve vent or a roof peak vent. Use the metal flashing and the foam spray to seal the exhaust duct to the eve or roof vent. Support the duct with plastic or wire ties to be sure the duct does not fall down over time. An exhaust fan has a 1 way flapper valve in the exhaust fan body before it attaches to the duct. Given the opportunity, inspect the flapper valve and make sure lint, dust, hair, moisture and gunk has not 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.
7. Now take the can of spray foam and apply foam to each hole where an electric wire, T.V. cable, or telephone cable enters or leaves the attic. There ought to be vent pipes running up from the loft floor and out the roof. Foam where the pipe comes through the attic floor.
8. Some homes, both older homes and newer, may have open framing spaces which run from the attic floor down to the floor below. These are spaces that result from unneeded space at the end of bathtubs or closets. They maybe the result of irregular framing such as a triangle formed where a closet meets a hallway that meets a bedroom door. These open chases need 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, lay the cardboard on top the the caulk and twist down with the sheet metal screws. Now you just insulate over the cardboard.
Ready to Resist
1. Tape measured- for calculating the square footage in your loft and for marking cardboard strips with the depth of insulation that you would like to add.
2. Either one is good.
Hint – fiberglass is itchy, cellulose not so much.
3. Insulation – Large hardware and construction stores will have a blower you can use should you purchase the insulation from them. Do not 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 rarely new item for insulating over the attic access opening after you have insulated the rest of the attic.
6. Little roll about 12 feet long.
7. Gate latch – two little gate latches for holding the access lid down.
8. 1 buddy – flip a coin, 1 person to spray the insulation in the attic and one person to feed the machine in the garage or back yard.
Take the tape and measure the width and length of the attic 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 loft.
Take a trip down to your favorite hardware store and head for the insulation department. Grab a bundle and read how much insulation is in the package at a particular thickness or depth. The graph on the package will allow you to calculate how many packages of insulation you will need if your attic is so many square feet and you want to add as much R-value. For instance, one package will cover 100 square feet at R-16, 56 square feet at R-30, and 32 sq ft at R-49.
Tip – buy a bundle or two additional, once you start blowing insulation you don’t want to stop to go get one more bundle.
Load up the blower and the insulating material in the rear of the pickup and head home for a good, energy saving day.
Place the blower at a handy location. You will have to plug the machine in to an electric outlet, feed it with bundles of insulation, and run the hose from the machine to the attic. Tack up a couple of the cardboard depth indicating strips that you made so you’ve got a target depth to aim for. Start in a back corner and work your way to the attic access opening. Spray the insulation from the hose in a sweeping motion which allows the insulation to fall on your loft floor like a fine light snow. Fill 1 section of loft to the intended depth before moving on to another section. Be careful not to guide the flying insulation into the eve chutes or within the cylinder barriers.
Tip – If your attic has an electrical junction box or some other fixed thing 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 signal over the thing on a roof rafter with an arrow pointing the way.
Fill the whole attic with fine new insulation to an even depth indicated by the cardboard thickness measuring strips placed efficiently around the attic. As soon as you have all of the attic filled except only the area around the attic access opening, stop for a moment, take some cardboard, and install an insulation barrier around the opening. Now you can add insulation to the proper depth right up to the opening.
Tip – Plan ahead so the hose and the mill hopper isn’t full of insulation when you’re finished and need to take the hose off the machine.
Hey, you’re almost done.
1. Spread the attic access tent over the opening.
2. Attach the 1/4 inch self adhering weatherstripping to the touch perimeter of the lid that fits covers and into the access opening.
3. Install the hatch latch clips, one on either side of the lid in such a way that when 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 insulating material and the blower and return to the store.
There is certain to be a light sprinkling of insulation under the access opening and around the region where the blower was located. Brooms don’t work well on insulation in grass or carpet. Catch the vacuum cleaner and do not stop until your sure you won’t need 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 does not 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…