- Insulate the joists: Cut the strips to size. Cut rigid foam insulation into strips with a table saw or a circular saw. ...
- Caulk around openings. Run a bead of acrylic caulk around each section of foam to form an airtight barrier. Fill gaps larger than 1/4 in. with expanding foam sealant.
- Figure A: Insulated Rim Joists
How to install insulation between the rafters?
Divide the space in between the rafters by 3 and then install the two strips according to your measurements. This will give you the room needed for the ventilation and act as a stop when installing the insulation.
Is it possible to insulate between the joists?
Absolutely YES! With 4-5" of insulation between the joists (even at R10/inch), the 4-5" path through the rafter is only R5-ish, which is an ice-dam starter. Deepening the total insulation thickness to 9.5 would be R10-ish, even if all wood- half the heat loss, half the melt-out potential.
How do you insulate R value between floor joists?
Install 3-1/2" unfaced batts between the joists, then apply foam board to the faces in sufficient thickness to reach the R-value you desire. Covering the joists with foam has the advantage of reducing the cold spots along each joist.
How do you insulate a concrete floor joist?
1 Insulate the joists: Cut the strips to size. Cut rigid foam insulation into strips with a table saw or a circular saw. ... 2 Caulk around openings. Run a bead of acrylic caulk around each section of foam to form an airtight barrier. Fill gaps larger than 1/4 in. with expanding foam sealant. 3 Figure A: Insulated Rim Joists
Should I insulate my rafters?
Insulating between rafters will do no good, because the attic should be ventilated, and the rafter insulation would be between two unheated spaces. You can add insulation to the floor; the more the merrier. Just don't put it in the eaves. Also, make sure the attic is well ventilated.
Should you insulate the underside of your roof?
roof insulation is no-contest. The floor wins every time. Insulating the floor is standard practice for an unfinished attic space. The exception to this rule takes place when families opt to convert an unfinished attic space into something usable or livable.
Should you insulate floor joists?
Insulating the joists can help create an effective vapor barrier that will keep humidity from sneaking inside your basement and causing the joists to expand and contract. This can be beneficial if you have hardwood floors and are all worried about moisture seeping up from the panels due to bad insulation.
Should I insulate my loft rafters?
Insulating your loft, attic or flat roof is an effective way to reduce heat loss and reduce your heating bills. Installed correctly, loft insulation should pay for itself many times over in its 40-year lifetime.
How do you insulate a roof with exposed rafters?
If your structure does not need to be well insulated, you can simply sandwich a layer of aluminum foil insulation or rigid foam between your finish ceiling and a layer of sheathing. Place the sheathing layer on top of the insulation and secure it with nails that pass through the insulation into the rafters.
Can you have too much insulation in your attic?
It's possible to over-insulate an attic as too much will cause moisture buildup and eventually result in mold. Eventually, adding more insulation leads to diminishing returns in trapping heat as well.
How do you insulate rafters?
2:038:37The Right Way To Insulate: Attics and Cathedral Ceilings with BattsYouTubeStart of suggested clipEnd of suggested clipSpace make sure it covers the top plate of the wall. Staple as you go. Continue to add bats pushingMoreSpace make sure it covers the top plate of the wall. Staple as you go. Continue to add bats pushing them snugly up against the end of the first bat with no gap.
How do you insulate the end of a joist?
5:227:08Sealing and Insulating Rim Joists - Best Practice - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnd it requires you to cut 2-inch thick rigid insulation board to fit between the floor joists glue.MoreAnd it requires you to cut 2-inch thick rigid insulation board to fit between the floor joists glue. And fasten them up against the rim joists. This can be both time-consuming.
What insulation should I use between floor joists?
Insulate Under Floor: Fiberglass insulation batts or rolls are the most economical and easiest DIY choice for insulating between the floor joist in a crawl space. The U.S. Department of Energy recommends R-11 (3½”) insulation under floors in warm climates and an R-25 (6” to 8”) in cold climates.
Can you lay loft insulation over joists?
The base layer won't cover the entire loft floor as the rolls are laid between, not over the ceiling joists. By deducting this amount, it calculates a more accurate area to be insulated for the base layer.
Is it better to insulate ceiling or roof?
If you are deciding between insulating the roof deck or the ceiling, Insulating your ceiling should be the priority. Not only is it easier but ceiling insulation is beneficial in a number of ways: Keeps the temperature in the building regulated. Saves on energy costs.
Can you over insulate a loft?
As long as you ventilate your property properly, you can have as much insulation as you like within reason. The trick with loft insulation is to balance the amount of insulation you have with the amount of ventilation necessary to prevent damp. As long as you get that balance right, you should be fine.
How deep can you use R15 foam batts?
If it's 5" of HFO blown foam, R15 batts would get you there, and you'd probably be able to achieve the 3.5" necessary depth with simpler Bonfiglioli strips:
How deep is a R30?
And 4" of HFO HighLift (R30) would have even more dew point margin, and would get you to code min with R20-R23 batts (5.5" deep) at 9.5" total depth.
Is 5 inches of spray foam insulation enough?
Jon, Dana hit the important points. Five inches of spray foam isn't enough to meet minimum code requirements. As Dana said, if you have HVAC equipment in your attic, the insulation should follow the sloped roofline. For more information, see "Creating a Conditioned Attic.".
Is there HVAC in the attic?
Currently, the attic is vented with fiberglass insulation between the joists. There is no HVAC equipment in the attic, however, we may add central air in the next few years. The contractor recommended insulating in between the rafters and conditioning the space.
Does R20 foam help with ice damming?
At my home in central MA (a snowier, somewhat cooler climate than southern CT) putting R20 of open cell foam between full-dimension 2x6 rafters in the tiny attic spaces behind kneewalls in the built-out 1.5 story made a huge difference in the amount of ice damming, but didn't prevent it completely. When re-roofing in short years I'll be doing a foam-over with R25-ish polyiso to better protect the roof sheathing, which should also pretty much eliminate ice damming except around heat leaks such as skylights (which mi esposa demands we keep.)
How should a home be insulated?
For optimal energy efficiency, your home should be properly insulated from the roof down to its foundation. The illustration above shows all the areas of the home where there should be insulation. The numbered areas shown in the illustration are as follows:
How to add insulation to exterior walls?
In an existing home, consider using blow-in insulation, which, when installed with the dense pack technique, will provide a higher R-value. It can be added to exterior walls without much disturbance to finished areas of your home. If you’re remodeling and your wall cavities will be open, look into two-part spray foam or wet spray cellulose insulation. If your wall cavities are not going to be open, you could consider injectable spray foam insulation. If you’ll be doing the work yourself, blanket (batt and roll) insulation, while not capable of providing an air seal as and two-part spray foam will, may be an affordable option.
What to consider when building a house with radon?
If radon is an issue where you live, you’ll also need to consider radon and radon-resistant construction techniques as you research foundation insulation options. In addition, if you live in an area with termites, you’ll have to consider how termite protection will affect the choice and placement of insulation in your home and plan for a means of inspection.
When insulating floors above unconditioned garages, first seal all possible sources of air leakage.?
When insulating floors above unconditioned garages, first seal all possible sources of air leakage. This strategy has the added benefit of minimizing the danger of contaminants (from car exhaust, paint, solvents, gardening supplies, etc.) in the garage migrating into the conditioned space. Also install an air barrier to prevent cold air in the garage from "short circuiting" the insulation underneath the subfloor.
What is foam sheathing?
Foam sheathing: Provides a continuous layer of insulation, which reduces thermal bridging through wood studs, saving energy and improving comfort. Is easier to cut and install than heavier sheathing products. Protects against condensation on the inside wall by keeping the interior of the wall warmer.
Why do you need fire rated insulation in basement walls?
Here are a few things to consider when installing interior basement wall insulation: Many insulation types require a fire-rated covering because they release toxic gases when ignited.
What to do if ducts are in a new house?
If you’re building a new house, place ducts in the conditioned space to avoid the energy losses associated with most duct systems.
What is the best insulation for rim joists?
Rigid foam is the best insulation for rim joists. We chose 2-in.-thick (R-10) "extruded polystyrene.". Don’t use "expanded polystyrene," which is a less effective air and moisture barrier. Cut the foam into 8-ft.-long strips 1/8 in. less than the height of the rim joist.
How long does it take to insulate a rim joist?
If you have an unfinished basement, you can properly insulate the rim joists in two or three hours.
How to make a foam barrier?
Run a bead of acrylic caulk around each section of foam to form an airtight barrier. Fill gaps larger than 1/4 in. with expanding foam sealant.
How to reduce heat loss in a house?
Cut heat loss through the rim joists and tighten up your house with rigid foam insulation.
Can you use foam to cover rim joists?
Use long sections of foam to cover the rim joists that are parallel to the floor joists (Photo 2). Don't worry about cutting the foam for a tight fit around pipes, cables or other obstructions; you can seal large gaps with expanding foam sealant later.
Why vent attic space during summer?
Venting the attic space during summer to cool the house
Do spray foam roof shingles get hotter?
they spray foam these units all the time - I agree with you - the roof/shingles get hotter reducing the lifetime of both. Not too mention what happens with a leak - you don't know until your whole roof is full of mold!
Can you vent an attic?
You should not. Because the attic is vented, the upper insulation does almost nothing. In the summer at the attic will get much hotter than it does now, increasing cooling costs.
What is roof insulation?
Roof insulation refers to the practice of installing insulation on the roof slope, both above and below the rafters. Ceiling insulation refers to any type of insulation installed within the floor nearest to the roof structure of the home.
Why do you insulate your roof?
You may also insulate your roof to help regulate the temperature in an attic that is a part of your living space.
What is rigid foam board insulation made of?
Rigid foam boards used in ceiling insulation are often made of either cellulose fiber, fiberglass, polystyrene, or polyurethanes.
What is the best material to insulate a ceiling?
Rolls of either glass fiber or loose-fill cellulose are the most popular materials used by DIY installers. Insulating a Ceiling is Affordable. Cellulose or wood fiber insulation is made from used newsprint, other paper feedstock, or wood. Chemicals are then added to the insulation in order to provide fire resistance.
What is a cathedral ceiling?
Cathedral Ceiling: this ceiling type involves exposing the sheetrock facing (or underside of the roof) to the interior of the home. The roof cladding (a portion of the roof at the exterior) runs parallel with the sheetrock facing, separated only by the rafters.
Why is it important to insulate a roof?
Properly insulating a home is a critical step in keeping the roof from accruing damage and saving energy costs. You may be faced with the choice of insulating either the ceiling or the roof. How do you know which is best for your home?
Where should radiant barrier be installed?
However, you should at least know that the most effective radiant barrier location is either below the bottom chord truss or underneath the roof sheathing.