what is the best insulation for cathedral ceilings

Best Way to Insulate Cathedral Ceiling

• Cellulose Cathedral Ceiling Insulation Cellulose insulation can be installed in your cathedral ceiling, but it can be a tricky installation. ...
• Fiberglass Cathedral Ceiling Insulation Fiberglass insulation is the next option for your cathedral ceiling. ...
• Open Cell Spray Foam Cathedral Ceiling Insulation Spray foam is another option for your cathedral ceiling, more specifically open cell spray foam. ...

Full Answer

How to insulate a cathedral ceiling with no attic?

Steps Download Article

1. Seal all ceiling openings. Stand on a ladder and using a caulk gun, seal any areas where there is visible wiring or plumbing.
2. Install baffles on vents. Also called vent chutes, the baffles will make sure there is enough air flowing for ventilation needs.
3. Continue installing baffles until baffles are attached to all the vents.

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How much to install a beam in cathedral ceiling?

“High-quality beam stock in white oak is now running about $15 per board foot. But you also have to factor in drying, manufacturing, engineering, finish, and installation costs. “For example, a remanufactured beam that’s 10 feet by 12 inches will be about $300 to $350 per a linear foot,” he says.

How to vent a cathedral ceiling?

Ventilating Cathedral Ceilings

1. The Flow of Water Vapor. To understand the necessity of proper ventilation, it helps to have a basic understanding of water vapor movement.
2. Sealing Bypasses - The First Line of Defense. Attic bypasses are hidden air passageways that lead from the heated space into the attic and are often the cause ...
3. Vapor Retarders. ...
4. Proper Ventilation. ...

Do cathedral ceilings need ventilation?

Because of the isolated air spaces in rafter cavities, cathedral ceilings are especially prone to moisture damage - posing unique ventilation problems. Special attention to the avoidance of water condensation and the management of water vapor and its flow throughout the attic is extremely important to preserving the service life of the roof.

What kind of insulation do you use for a cathedral ceiling?

Spray Foam Insulation This is important in a cathedral ceiling because it helps keep the heat and cool air where it belongs – in your house, and not outside. Spray foam insulation is also energy-efficient, meaning it can save you a lot of money in the long run.

What R-value insulation do I need in a cathedral ceiling?

High-performance batts are specially designed for the space limitations in common cathedral ceilings. They have R-values of either 30 or 38. R-30 high-performance batts are 8-1/4˝ to 8-1/2˝ thick as opposed to standard R-30 fiber glass insulation batts of 9-1/2˝ to 10˝ (thickness may vary by manufacturer).

What is the best way to insulate a vaulted ceiling?

For years, fiberglass batt insulation was the only way to insulate vaulted ceilings. Over time, fiberglass batts can slide out of place and compromise your home's energy efficiency. When insulating a vaulted ceiling, R-value and moisture management must be addressed. Spray foam insulation can achieve both.

How do you insulate an existing cathedral ceiling?

0:443:00How to Insulate a Cathedral Ceiling in an Existing Home with Foam ...YouTubeStart of suggested clipEnd of suggested clipSo again basic steps you cut an access strip in the drywall of the cathedral ceiling remove theMoreSo again basic steps you cut an access strip in the drywall of the cathedral ceiling remove the existing insulation that's in there and then spray foam down each stud cavity to get your fill.

Should you insulate the underside of your roof?

The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams, and the material will block that flow. For the same reason, insulation shouldn't touch the roof's underside.

Should a vaulted ceiling be insulated?

Basic Insulation Tips for Cathedral Ceilings Cathedral ceilings are beautiful, but they must be properly insulated to keep ceiling temperatures closer to room temperatures. To do this, the cathedral ceiling must be built with space between the roof deck and your home's ceiling for adequate insulation and ventilation.

Does a cathedral ceiling need to be vented?

Ice dams may cause water to flow laterally underneath a steep-slope roof covering and eventually enter a building's interior. For these reasons, cathedral ceilings should be ventilated.

How do you insulate cathedral ceilings without ridge vents?

In cases where there is no under-roof venting system (no soffit intake vents, no ridge vents), a "hot roof" design is followed: the roof cavity between rafters can be filled with insulation, followed by installation of a perfect vapor barrier, followed by finish surface of drywall or whatever else.

Can you spray foam a cathedral ceiling?

The best method to insulate a cathedral ceiling is with spray foam insulation. The crew will cut panels and spray the foam. While the installation process is somewhat invasive, spray foam insulation creates the air barrier you're looking for to stop air leakage.

How do you insulate a ceiling without removing it?

Injection foam insulation is the answer to insulating walls without removing drywall. There are several types of injection foam available out there, including the RetroFoam product we use. These materials don't require the drywall in your home to be taken down.

Can you spray insulation into existing ceiling?

The answer is yes, but drywall needs to be removed before you can install the foam. Spray foam expands rapidly when it is applied to the inside of walls. If you try to add the insulation without removing drywall, the expanding foam may overfill the panel and exert pressure against the inside of the plasterboard.

How do you insulate a roof with exposed beams?

How To Insulate A Ceiling With Exposed RaftersInsulate the roof deck.Insulate between the rafters (including air barrier).Add external cladding to the rafters after insulating normally.

How do you insulate a vaulted ceiling with exposed beams?

How To Insulate A Ceiling With Exposed RaftersInsulate the roof deck.Insulate between the rafters (including air barrier).Add external cladding to the rafters after insulating normally.

How do you insulate a ceiling without an attic?

Insulating a Roof Without an AtticInstall rigid foam board into the ceiling. This material is thin and typically has impressive R-values.Install high-quality blown insulation into the ceiling. This material fills up the gaps around plumbing and electrical elements very well.

How do you insulate a vaulted ceiling in Canada?

Install a continuous layer of vapour barrier over the warm-in-winter side of your ceilings and seal it with caulking or tape, leaving at least a 6” overlap over the joints. Make sure you have appropriate venting by installing rafter vents or soffit and ridge vents.

How do you install foam insulation on the ceiling?

3:425:11Installing Rigid Foam Insulation - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo yeah you just measure it out and just slide it right in fits in nice and snug you push it in andMoreSo yeah you just measure it out and just slide it right in fits in nice and snug you push it in and you're good you can use some kind of sealer tape.

What is the Money Pit Guide to Insulation?

We wrote an e-book on it. It’s called The Money Pit Guide to Insulation. It talks about all the different insulations and the pros and cons of each. And that’s on our website at MoneyPit.com.

Is the attic the same temperature as the rest of the house?

So in my house, when I go up in my attic, my attic is pretty much the same temperature as the rest of the house, within a few degrees, even though it’s not heated or cooled up there. It’s just an old-house attic.

Can you insulate with fiberglass?

TOM: No. No, because it’s a different system. So the – when you insulate with fiberglass, you have an unconditioned attic space, so to speak, OK? When you insulate with spray foam, you now have a conditioned attic space. The difference is that when it’s unconditioned, you have to ventilate it to carry the moisture out. When you use spray foam, there’s really no – the moisture is really no longer an issue.

Does icynene insulate?

TOM: It does. And that’s the other advantage of it because it both air-seals and it insulates at the same time. So we used Icynene. I’m very happy to recommend it. It’s a great product.

Can you insulate with spray foam?

When you insulate with spray foam, you now have a conditioned attic space. The difference is that when it’s unconditioned, you have to ventilate it to carry the moisture out. When you use spray foam, there’s really no – the moisture is really no longer an issue.

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 do cathedral ceilings add value?

Cathedral ceilings are a feature in many homes that add to value to the house because the high ceiling tends to make rooms look larger. It provides an open, airy look and feel to the room and they are often in demand among home buyers. While many people think they look nice, providing insulation can sometimes be a challenge due to ...

How to cover gaps in a house?

Cover any gaps by cutting some scrap insulation that was not used and plug the holes.

How to protect a room from fire?

Stand on a ladder and using a caulk gun, seal any areas where there is visible wiring or plumbing. Check the joists and wall plates for any holes or openings. Be sure to seal around any PVC pipes as well. This will protect the room from air infiltration and will also suppress fires. ...

What is a baffle in a vent?

Also called vent chutes, the baffles will make sure there is enough air flowing for ventilation needs. Baffles are available in prefabricated models, built to fit the measurements of your ceiling joists. Put the baffle between the joists, starting where they join at the exterior wall plate.

Where do you put baffles on a wall?

Put the baffle between the joists, starting where they join at the exterior wall plate.

How much space do you need for a kraft paper roof?

Press the Kraft faced insulation batts between the joists. The side exposing the kraft paper must face downward. There must be at least 1 inch (2.54 cm) of space beneath the roof's plywood sheathing. This will ensure adequate airing. ...

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.

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.

Is spray foam insulation cheaper than foam board insulation?

Spray foam is a very expensive option, however. Foam-board insulation would be a more economical, especially if you are supplying the labor (see photo).

Can you insulate a cathedral ceiling?

The ceiling is vaulted at an angle, and there’s no attic space above the ceiling. According to Green Building Advisor , the best way to insulate the ceiling depends on whether you have a ventilated or unvented roof assembly.

Do you need to seal a flat ceiling before installing insulation?

If your home or business has a flat ceiling with no attic space, it’s critical to air seal any ceiling penetrations before installing insulation. Also, plan to ventilate the space with intake vents and cupolas.

How many words are in the article "How to build an insulate cathedral ceiling"?

When people post questions on the Green Building Advisor forum about cathedral-ceiling insulation, they are often directed to a 3,800-word article from 2011 called “How to Build an Insulated Cathedral Ceiling.” While the comprehensive information in that article—including detailed discussions of vapor diffusion, condensation risks, and failure modes—is useful, it may represent information overload for many builders.

What insulation is needed for a climate zone?

The illustration shows an assembly with R-38 insulation, which is enough insulation for Climate Zones 1, 2, or 3. If you live in a colder climate zone, you’ll probably need insulation with a higher R-value.

How to calculate R value of roof?

To calculate the total R-value of your roof assembly for code compliance purposes, add the nominal R-value of the batt insulation to the nominal value of the rigid foam layer. For example, if you combine R-30 batts with 2 inches of EPS (R-8), code officials will consider the assembly to have a total R-value of R-38. If you combine R-38 batts with 2 inches of polyiso (R-11), you’ll end up with an R-49 assembly.

What is the insulation between the rafters of a roof?

This type of roof assembly combines a continuous layer of rigid foam above the roof sheathing with fluffy insulation (fiberglass, mineral wool, or cellulose) between the rafters.

What are the disadvantages of spray foam insulation?

There are three main disadvantages to this approach: 1 Most brands of closed-cell spray foam use a blowing agent that has a high global warming potential—meaning that this type of insulation is not environmentally friendly. 2 Closed-cell spray foam is expensive. 3 This approach fails to address thermal bridging through the rafters.

What is the R value of a spray foam roof?

Here are the required minimum R-values for the spray foam layer: R-5 in Zone 1, 2, or 3; R-10 in Marine Zone 4; R-15 in Zones 4A or 4B; R-20 in Zone 5; R-25 in Zone 6; R-30 in Zone 7; and R-35 in Zone 8. The R-value of the total roof assembly will be higher than these numbers, of course, because the fluffy insulation also provides significant R-value.

How deep should a vent be on a rafter?

Most builders use a ventilation baffle to define this air space. The air channel must be at least 1 inch deep—2 inches is better—and must be connected to soffit vents at the bottom of the assembly and a ridge vent at the top of the assembly.

What is the best way to insulate cathedral ceilings?

The Best Practice for building insulated cathedral ceilings is to create an airtight roof assembly. You have two Best Practice options: vented batt insulation and unvented spray-applied insulation.

How much space does a cathedral ceiling need?

Cathedral ceilings built using 2 x 12 roof rafters allow enough space for the fiberglass batt insulation and a 1.5" gap for ventilation. This type of roof assembly is designed so the air can flow up the soffit vent, through an insulation baffle, pass through the 1.5" gap between the insulation and roof sheathing, then exit through a ridge vent.

What to use to seal a drywall box?

Use foam gaskets or caulking to seal any electric boxes or HVAC registers that penetrate the drywall.

Why is cathedral ceiling important?

Cathedral ceilings can add an element of grandeur to any new home, but it is important to use the proper building techniques to manage moisture and energy performance issues. Condensation in the insulated cavity space can lead to wood rot and mold, which can compromise the durability of the roof, the efficiency of the home, ...

Does spray foam insulation work?

By using spray foam insulation, the second Best Practice option, air movement through the insulated space is stopped, so venting is not needed. The sealing nature of spray foam insulation works to make the ceiling cavity airtight. This will help keep moisture-laden air from entering and condensing within the insulation or forming on ...

Where to put foam board on roof?

On the inside of the roof, at the eave, fill the space between the top plate of the wall and roof sheathing with a piece of rigid foam board (this creates a stop or a block when spraying the insulation).

Does a nonvented roof increase the temperature of shingles?

There's been some talk in the industry that non-vented roof assemblies would dramatically increase the temperature of roof shingles, potentially diminishing their appearance and durability over time.