Whether it’s information on insulation and materials, or a deep dive into installation and target R-values, below is a comprehensive look at all the considerations to make before insulating your attic yourself.
Cost Savings from Insulating Your Attic
If you live in a cold climate, it can be very costly to maintain warmth in your house during the winter. Sadly, there is not much you can do about it. According to the Department of Energy, heating oil and natural gas prices are likely to be higher this winter than during the last one. Though the said prices saw sharp spikes in most parts of the country just last year, that prediction stands.
Technically, you can try to get comfortable wearing bulky sweaters indoors, or you can turn down the thermostat. Alternatively, properly insulating your unfinished attic is one of the best ways to mitigate against a high heating bill. Tom Silva, a TOH general contractor, describes it as a DIY project that you can complete in a weekend and see compounding savings every year. According to the Department of Energy, you can save 10% to 50% off your heating bill if your attic is insulated well. The reverse applies to warm climates, as you can stabilize indoor temperatures to keep a cool internal environment.
In an ideal situation, you could procure an energy auditor’s services who can pinpoint the amount of protection you’re getting from the current level of attic insulation. Additionally, such a professional can identify air leaks that interfere with the said insulation, after which you can seal them. However, you may not have a few hundred bucks to spare for such a service. There is no need to fear, though, as we have put together a slew of information about the cost, prep work, installation, and products that feed into the attic installation process. Continue reading for more details.
Costs Associated with Attic Insulation
Based on Home Advisor information, it can run you between $1700 and $2100 to insulate your attic. The chief cost influencers are:
● The material and type of installation
● The measurement of your attic in square feet
● The insulation installer or contractor’s fee
You should note that there are cases in which insulation must be done around cables or electrical boxes. If this is the case for you, you may need the support of an electrician as well.
Begin with the Attic’s Floor
It’s time to break the habit of using the attic for storage purposes. Are you wondering why? Well, adding material to the floor is the cheapest and most straightforward way to insulate your attic. However, if you have a plywood covered floor, you can’t put enough insulation under it to effectively get the job done. This principle applies even if the climate is warm.
Therefore, it’s best to plan to pull up the flooring and set a new insulation layer atop the old one. Without the floor, you will need to find somewhere else for stashing that holiday decor and those off-season clothes you barely wear.
Select the Material and Insulation Type
You have two options for DIY attic insulation. There is batt, which is another way of saying blanket insulation, and there is loose fill. You can layer over existing material, or you can add either option to an uninsulated attic. Once you settle on a type, carefully consider the materials and prices to select the right product. Labels are your friends, and they provide you with the specifics on whatever you hope to buy.
Batts | What should I choose?
This alternative is available in standard widths of 16 inches or 24 inches, and there are also various thicknesses. It’s packaged in rolls, and it happens to be a very flexible insulation material. Batts are built to slot between studs or joists in the framing of a house. Sometimes, there is a paper foil facing that serves the purpose of a vapor barrier. Depending on the insulation level you want, you can add one or more layers.
Batts work best for the following:
● Attics that have a standard joist spacing, particularly if there is no insulation
● Attics that don’t have many penetrations or obstructions to workaround
● Attics with acceptable maneuvering headroom during installation
● DIYers who are OK with getting the material to fit around obstacles by cutting it
Insulation Material Choices
● Fiberglass: Fiberglass has an R-value of 2.9 to 4.3 per inch. Its composition is that of fibers that are the result of melted and spun sand or recycled grass. It’s common and cost-effective, but the fibers can become irritants to your skin and lungs. Thankfully, better manufacturing means that this is less of a problem now than it used to be. Note that other materials are more effective at airflow blocking than fiberglass is.
● Cellulose: Cellulose has an R-value of 3.7 to 3.8 per inch. The composition consists of recycled post-consumer paper, which goes through a fire and insect resistance treatment process. While you will not have to deal with skin or lung irritation, only select manufacturers make the product.
● Mineral wool: Mineral wool has an R-value of 3.0 to 3.3 inches. It’s comprised of fibers from recycled slag or rock from blast furnaces. It has natural fire resistance, and it’s costlier than the other alternatives.
● Cotton: Cotton has an R-value of 3.7 to 3.8 per inch. The composition is that of recycled denim cloth fibers. It’s a more expensive material than others, but it effectively mitigates sound and airflow transmission.
Loose Fill | What’s the best for me?
This alternative consists of bags of insulation fibers. You can rent special machines from a home center to blow the fibers in place to achieve the desired density and depth. Alternatively, you can spread the fill manually after pouring it in place, but the results will not be as good, and the process is more labor-intensive.
Insulation Material Choices:
● Fiberglass: Fiberglass has a 2.2 to 2.7 R-value per inch. Its composition is that of fibers that are the result of melted and spun sand or recycled glass. Fiberglass offers a lighter alternative to mineral wool or cellulose, but it settles more than either, which means achieving the desired protection requires a thicker layer.
● Cellulose: Cellulose has an R-value of 3.2 to 3.8. The composition consists of recycled post-consumer paper, which goes through a fire and insect resistance treatment process. While it can grow moldy and rot if exposed to moisture, it stands as the most popular blown-in material used.
● Mineral wool: Mineral wool has an R-value of 3.0 to 3.3 per inch. It’s composed of fibers from recycled slag or rock from blast furnaces. While it does offer natural resistance to fire, it’s the costliest of loose-fill materials.
Evaluate Your Current Insulation Situation
You need to understand how deep the current insulation in your attic is. A flashlight and a tape measure should help you with this. You can then use the numbers to estimate the R-value. You should remove any moldy, water stained, or compressed material for best results since it’s not helping anyway. If you own a house built before 1990 and your insulation seems grainy, lightweight, or loose looking with shiny flecks present, that could be a big problem. You may be looking at vermiculite derived from an asbestos deposit-filled mine. Your best bet is to get it tested, after which you can get a pro to remove it if needed safely.
Establish Your R-value Goal
You can review the minimum recommended values for unconditioned and unfinished attics made by the Department of Energy. The numbers provided make considerations for your climate zone and your house’s location.
Check for Credits or Rebates in Your Region
In 2011, most federal tax credits associated with energy efficiency-boosting and house weatherizing expired. However, your local utility company or your state’s energy office probably offers discounts, product rebates, and other beneficial financial offerings related to insulation. You can view specific information for each state here.
How Much Should You Buy
Begin by getting an adequate measure of your attic’s square footage. If you’re using batts or rolls, base your calculations on the length and width of the product you intend to use. If you’re going the loose-fill route, read the labels well. The bags show R-value ranges and the depths needed for them. You also get an adequate measurement of how many bags you need to cover 1000 square feet at each depth measurement. Regardless of which of the two options you go with, get one extra roll or bag. One of the worst feelings is running out of material when you’re almost through putting things in place.
Most Important Prep Step: Air Leak Sealing
If there are any gaps in the attic or any present between it and the lower floors, you risk cooled or heated air escaping outdoors. Once this happens, your insulation effort is for naught. Here’s a quick crash course on taking care of some draft-prone areas.
Attic windows: Minimally expanding spray foam in a can should do the job when sprayed around the casing. Use foam weatherstripping around the jambs and sash to seal leaks.
Ducts, exhaust fans, pipes, wires: You can use a fire-blocking caulk to seal gaps that measure 1/4 inch or less. Larger ones that measure as much as 1/2 inch can be sealed with fire blocking the spray.
Flutes and chimneys: You can use metal flashing sealed with a high-temperature caulk or furnace cement for these sealing jobs.
Other Essential Pre-insulation Steps
If you want your insulation to stand the test of time and consistently work well, take care of these items before going to work.
Address roof leaks: Water and insulation do not work well together. Mildew and mold, which water creates a breeding ground for, compromise your heat flow by blocking air-trapping pockets. Try to identify water stains on your roof sheathing to give you an idea of where the leaks may be. Additionally, check for moldy or damp areas on your attic joists.
Light fixture box outs: You should not allow your material to encounter lights or cover recessed cans from the below floor. Such contact is a fire hazard unless you use contact-safe insulation, such as mineral wool. If you don’t have that kind of material, you can use scrap plywood, metal flashing, or hardware cloth to set up a three-inch safety gap around your fixtures.
Exhaust fan and vent direction: It’s against building code to vent your exhaust to your attic. However, a lot of homeowners get away with doing it. Now is the time to correct that problem, which prevents humid exhaust air from ruining your insulation after becoming trapped inside it
Insulation is a job that you want to get through without being uncomfortable or injuring yourself. Here are a few ways to achieve that:
● Use Personal Protective Equipment (PPE): Such items include a long sleeve shirt, work gloves, goggles, long pants, and a dust mask. The idea is to prevent fibers from causing any irritation or damage to your skin, eyes, and lungs.
● Avoid standing on joists: Losing your balance could mean crashing through the ceiling. Employ sturdy whiteboards or plywood for your standing surface. For adequate stability, the board or plywood needs to span at least three joists, and you should move them around as you work.
● Dark corner illumination: Clip-on workshop lights or battery-operated lanterns work well for this purpose.
Maintain Attic Airflow
If you stuff your insulation along the eaves, you may end up covering soffit vents with batts or loose fill. That’s an outcome you want to avoid at all costs. This airflow to the ridge vent is to prevent ice dams and keep the roof cool. Insulation material in the wrong place blocks that natural flow. That’s also why you should avoid insulation touching the underside of the roof. You can staple foam baffles are plastic near the eaves to help you keep material away.
Vapor Barrier for Insulation from Scratch
Some batts are designed with a foil or a paper facing that plays a vapor barrier. Tom Silva uses six-mil polyethylene sheeting, which is cut well to fit between the joists. The seams have foil-tape sealing, ensuring that the insulation isn’t compromised by moisture seeping into it. Whether you go the batts or loose-fill route, the barrier should be closest to the warm areas of your insulation.
More Tips and Tricks for a Successful Insulation
Proceed by working from the attic’s perimeter and proceeding towards the hatch or door, which allows you to avoid trampling the installation you have just put in.
Ceiling joist tops need to be covered, ensuring that you have deep enough insulation to achieve your R-value. Additionally, it prevents thermal bridging, which speaks to the wood framing, and the heat loss.
Once you’re finished working for the day, shower well to eliminate lingering fibers on your skin, you should also ensure work clothes are laundered after a single wearing.
Whether you are attempting to avoid trapping moisture between old and new insulation levels, or you’re doing a first-time product laying, unfaced batts are your best bet. Feel free to get rid of the foil backing or paper.
Ensure that you place a new layer of batts in a perpendicular position to the old one. That helps you to cover whatever gaps may be present in the lower layer. You don’t want your batts to be so tight that they are compressed, but you do want them to be butted together snugly enough.
Heavier batts should never be laid over lighter ones. For example, you want to avoid laying cotton over fiberglass. Doing so reduces the effectiveness of the lower layer because of compression.
Batts should always be cut to fit around penetrations and obstructions adequately. If you go the route of cramming or stuffing them around your piping, ducts, etc., you risk compressing the material’s air-trapping pockets. Of course, that hurts your insulation objectives.
There should never be any gaps between your batts and obstructions, joists, or abutting batts. Air can escape through even the narrowest of spaces. Therefore, size the insulation you’re using well and cut a thin strip of it.
You don’t want your material to escape through the door or hatch during installation, so fasten blocking around the area.
Aim for a uniform fill depth throughout the attic. It’s recommended that you affix depth guides to your joists in the space so that you can easily look and evaluate the level of the material during the bluing process.
Remember to incorporate the number of bags the label indicates you need based on the R-value you want to achieve. Under no circumstances should you use fewer bags. You may find that you have a few bags left after you get to your target depth. If so, continue to add more at an even depth until you’ve reached the required bag number.
Ensure that the blower hose you are using is parallel to the floor and its joists so you can get the optimal density. Instead of blowing the fill across joists, blow it between them.
Access Spot Protection
● Attic door: On the door or hatch’s attic side, it’s recommended to set rigid foam insulation. Weatherstripping is good for the perimeter, and a walk-up attic should have a sweep to the door.
● Ladder or pull-down stair: An insulated tent with a zipper is perfect for ensuring that you maintain a draft-free closure.
A good idea is the cut batts with a chef’s knife. While utility knives are usable, pros tend to prefer the chef’s alternative because the insulation material is thick. A chef’s knife has an enormous blade, which makes the cutting that much easier. Stand on a scrap 24 to guide your cuts with a straight edge, and use plywood for your cutting surface.
Finishing Your Attic Someday?
You may have plans of converting your attic into conditioned living or storage space. If so, you may want to consider insulating between the wall joists and rafters instead of doing so to the floor. As Tom Silva does with nearly all his recent designs, you can opt to use rigid foam panels. It’s best to have a professional do the spray foam insulation on your behalf.
Foam is excellent for blocking airflow, it has a greater per inch R-value than batts or loose-fill, and it doesn’t even need a vapor barrier. Therefore, with less depth, there is greater protection. Soffit vents need to be covered if you’re using spray foam instead of batts or loose fill. The good thing is these vents are not required to keep the roof cool. To prevent a fire hazard, you’re going to need to cover the foam with drywall then.
Frequently Asked Questions
Attic insulation is not the kind of area that people are going to understand overnight. Even if you leave it in the professionals’ hands, you likely have some concerns that you need to be addressed before you go ahead with the process.
It just so happens that all the questions that are asked most are listed below with associated responses to help you to put your mind at ease.
What Difference Is There Between Loose Fill, Batts, and Spray Foam?
Loose-fill, batts, and spray types are all alternatives for your insulation needs. Loose-fill has a free and fluffy texture that gets into your attic or your walls, thanks to a blowing process. Batts take on the form of sheets, and they are laid on the floor or walls. Sprayed insulation makes use of foam based on polyurethane.
Am I Required to Remove My Current Insulation?
While it’s likely that your current insulation needs to be removed, the possibility exists that it can remain as is. The greater the amount of insulation, the more the R-value is going to be affected.
Removing your current insulation is normally a question of its condition. If it is moldy or damaged, the new material’s effect will be lost completely. Therefore, in cases such as those, it is best to have your old insulation removed.
If not, however, nothing is preventing adding the new layer atop the old one. If nothing else, it raises the R-value and insulation quality, which means that you get greater control over the airflow in your attic.
As far as walls are concerned, the additional insulation material can be installed to compress the existing one.
What Implication Does the Insulation Have on the Value of My Home?
The real estate industry looks at many different facets of the home to determine its value. The more positive features you have in place, the greater the likelihood for your home to appreciate. Having insulation in place means that there are fire resistance and environmental safety built into the house. Apart from these elements directly related to the design, there is also the benefit of lower utility bills than usual. Cost-saving is always going to be attractive to any potential buyer.
How Long Is the Insulation Process?
The time taken for insulation depends on the size of the area to be worked on. Nevertheless, attic insulation is typically not a process that spans multiple days. A whole-home can be insulated in one or two days. Therefore, the standard attic can be taken care of in several hours.
Why Is the Attic the Best Place to Insulate on a Budget?
Ideally, you want to insulate the entire house. However, if you are on a budget, the attic is the most important area to take care of. Why? When the climate is cold, most of the heat escapes your house does so through the attic. Conversely, that’s where most of the hot air comes in when the climate is in its hotter state.
Insulating means that you address one of the biggest contributors to your heating bill.
What Are the Signs That I Need Insulation?
Several factors indicate a re-insulation is in order from your home. Do you have to run your AC unit or furnace consistently? Do you find that there is moisture in your attic? Are your heating and cooling bills high? Do you notice drafty walls or ice dams?
If you answer any of those questions affirmatively, it is likely a sign that the airflow in the home could use some adjustment.
What Is the Meaning of R-value?
The R-value is a measurement used to indicate an area’s ability to resist heat’s natural flow. Higher R-values mean that the ability to do so is greater, which is a sign of better insulating power.
What Kind of Maintenance Comes with Insulation?
This is yet another area that insulation shines. Not only is it a process that does not have any associated risks, but you don’t need to do anything where maintenance is concerned. That’s one of the reasons why the process is seen as a solid investment. There are alternative methods for reducing utility bills while exercising control over the internal temperature. However, it’s hard to compete with insulation in value.