How deep should a vent be between insulation and sheathing?
Some builders make their own site-built baffles. According to the IRC, “A minimum of a 1-inch space shall be provided between the insulation and the roof sheathing and at the location of the vent.” Such a vent space can be created by tacking 1-in. by 1-in. “sticks” in the upper corners of each rafter bay, followed by stiff cardboard, thin plywood, OSB, fiberboard sheathing, or panels of rigid-foam insulation. Many experts advise that 2-in.-deep vent cavities are even better.
Do you need a shot from the soffit to the ridge?
You need a straight shot from the soffits to the ridge. That’s easy on a gable roof without any hips, valleys, dormers, or skylights, but if the geometry of your roof is complicated, it’s impossible to ensure adequate airflow through all of the rafter bays.
Can cathedral ceilings be vented?
That’s easy on a gable roof without any hips, valleys, dormers, or skylights, but if the geometry of your roof is complicated, it’s impossible to ensure adequate airflow through all of the rafter bays. Until recently, building codes required that insulated sloped roofs be ventilated. For complex roof designs, the International Residential Code (IRC ) now allows unvented cathedral ceilings.
Why is it important to insulate a cathedral ceiling?
Insulating a cathedral ceiling right the first time can save you a lot of headaches in the future , which is why it’s so important to know what the best insulation option is to get the job done.
What do you want when insulate your new home?
When it comes to insulating your new home there are likely a lot of things you want, like energy efficiency and making sure your home is comfortable, as well as healthy.
What happens if you don't cut fiberglass?
If the fiberglass isn’t cut to fit properly the studs in the ceiling, there will be voids left with no insulation coverage.
What happens to cellulose after it absorbs water?
After absorbing water, cellulose dries very slowly which causes it to deteriorate and settle. The chemical fire treatment is also destroyed.
Can you put cellulose insulation in a cathedral ceiling?
Cellulose insulation can be installed in your cathedral ceiling, but it can be a tricky installation. If your insulation contractor isn’t using wet applied cellulose, then they would have to staple a fine mesh screen to the underside of the roof trusses. They would then place the hose towards the top and fill in behind the mesh with cellulose.
Is cellulose insulation good for mold?
Cellulose can get into most nooks and crannies. Cellulose is an inexpensive insulation option. Boric acid, borax or aluminum sulfate used in cellulose insulation provides resistance to pests, mold, and fire. Cellulose has more recycled materials than any other commercially available insulation.
Does cellulose settle in a cathedral ceiling?
Cons: Modern cellulose settles up to 20 percent, which is problematic in relation to cathedral ceilings. This can lead to air leakage and high energy bills. Cellulose must be kept dry because it absorbs up to 130 percent water by weight.
How does moisture get into a ceiling?
The moisture could get into the ceiling from warm, moist indoor air leaking into the roof cavity through openings for ceiling lights, plumbing vents, or framing details that create gaps. Gaps in the insulation from installation errors can also expose the sheathing.
Why is my roof cold?
The reason is this: In cold weather, insulation in the roof cavity makes the roof sheathing colder (the sheathing is insulated from the warmth below). The colder roof sheathing is then more likely to form condensation or frost on its underside if household moisture reaches the sheathing.
Can you spray foam on a cathedral ceiling?
A: Assuming you have full access to the joist spaces from below, you could certainly spray foam up against the roof sheathing. In general, closed-cell foam is the best choice for unvented cathedral ceilings. It is also one of the most expensive, and most building inspectors will not allow it to be left uncovered (for fire-code reasons).
Can you use vapor retarder under a ceiling?
These roofs dry out very slowly, and almost entirely to the interior, which is why you should never use a vapor retarder under the finish ceiling with an unvented roof.
What is the worst material to insulate a cathedral ceiling?
Batt Insulation. Probably the worst material to lay for moisture control is fiberglass batting. This allows movement of air, but doesn't stop the moisture from penetrating behind the insulation. If you want to insulate your cathedral ceiling properly, then you need to develop another method of keeping in heat while avoiding becoming a target ...
Why do people avoid cathedral ceilings?
Cathedral ceilings were once popular due to their grandiose height and appearance, but these days many people avoid it because it is difficult to get proper cathedral ceiling insulation installed. If you are looking for the best way to install your cathedral ceiling, then there are some mistakes you'll have to avoid in order to prevent heat ...
What happens if you don't take care of the insulation?
If you don't take some measure of control, then you are likely to end up with mold or wood rot behind the insulating fabric , and this can have serious consequences. 2.
Why use loose packing in insulation?
Previous generations of insulation have relied upon the loose packing method to create pockets of air within the material, which was designed to provide a cushion of warm air between the heated house and the cold outside. This was a mistake, as the warm air carried water droplets into the insulation, and then cooled down sufficiently for the liquid to cling to the fabric.
Do you need moisture control for cathedral ceiling?
Moisture Control. When fitting your cathedral ceiling insulation, many people don't realize that you have to install a moisture control system. A traditional method involves putting insulation into your cavity, leaving a small area at the top to allow air circulation.
Can you use batting insulation on ceiling?
If you decide to use a batting insulation on your ceiling, then avoid another mistake and ensure that you caulk around the area thoroughly. You can also use vapor barrier paint to prevent moisture from spreading to the batts. 3. Dense Packing.
Why is it important to have a ceiling insulated?
Insulation helps keep your home cold in the summer and warm in the winter. Since it works to keep your home’s temperature steady, insulation is also regarded as a way to reduce heating and electric bills. Basically, if you want to make sure that your area is livable, you will want to make sure that you have your ceiling insulated—and ...
Why do we need insulation?
No matter where you live, your house needs to have solid insulation in order to keep you (and your family) comfortable. A lack of insulation will make cold intolerable, increase your air conditioning bills, and even cause humidity to potentially harm your furniture and items.
Why is insulation important?
A little insulation goes a long, long way! Insulation helps keep your home cold in the summer and warm in the winter. Since it works to keep your home’s temperature steady, insulation is also regarded as a way to reduce heating and electric bills.
Can you insulate a roof without insulation?
Insulating your home can reduce energy bills and maintain a comfortable temperature, and that applies to roof trusses as well. You cannot leave exposed roof trusses without insulation, and you can insulate them with rigid foam or panelized roof sections. Whether it be installing a built-up roof system, rigid foam insulation, or panelized sections, let’s take a look at how you can insulate exposed roof trusses.
Do you need to insulate exposed roof trusses?
Basically, if you want to make sure that your area is livable, you will want to make sure that you have your ceiling insulated—and that includes your roof trusses. So, how do you insulate exposed roof trusses? There are a couple of options that you can use to get a little more insulation, depending on your layout…
Do you need specialized experience to insulate a truss roof?
You don’t have specialized experience with built-up roofing or panelized roof sections. Since exposed truss ceilings are known for being difficult to insulate, having some specialty experience is a must. You do not have a crew to help you with the insulation.
Can you put aluminum foil on a ceiling?
Light Insulation Only. Another option to consider would be to just stick to the bare minimum in terms of insulation. If you need minimal insulation, sticking a layer of aluminum foil or foam between your sheathing and finish ceiling could work. All you need to do to fix it in place is secure it with nails.
What is a scissors truss?
More Musings of an Energy Nerd. A scissors truss is a roof truss that creates a sloped ceiling instead of a horizontal ceiling. Unlike parallel-chord trusses — a type of truss that creates a sloped ceiling that is just as steep as the roof — a scissors truss creates a ceiling that has a gentler slope than the roof slope.
Can you insulate a scissor truss?
Scissors trusses can be tricky to insulate, because loose insulation doesn’t generally like to be installed on a slope unless it is fully encapsulated by rigid materials (due to the risk that the insulation will slide downhill). Whatever insulation plan you come up with, talk to your insulation contractor before you order your trusses, because there is no use in specifying an insulation method that your local contractor won’t agree to.
