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Spray Foam Insulation

How Do You Insulate a Vaulted Ceiling?

Insulate A Vaulted Ceiling

This article is going to run through how to insulate a vaulted ceiling - if you do have questions after reading this article please do get in contact with one of our experts.

Instead of square corners, flat ceilings and sloped roofs, recent home design has experienced a growth in the use of more elaborate structures. Increasingly, modern, residential plans and renovations include vaulted ceilings as a common architectural feature.

As vaulted ceilings become more popular, more challenges have arisen around how to incorporate them in a responsible construction plan.

The unique configuration a vaulted ceiling presents, makes using the methods intended for insulating a traditional flat ceiling with attic space under the roof far more challenging-but not altogether impossible. A little forethought can work wonders in helping you figure out ways around it.

Once you have chosen to include one, things like skylights, lighting fixtures and the like further complicate the question, “Now that I have it, how do you insulate a vaulted ceiling?”

The article below aims to provide an answer, and offer some invaluable advice on all aspects of vaulted ceiling insulation. Let’s get started…

Insulating a Vaulted Ceiling

As your energy supplier continues to hit you with ever increasing costs, working out ways to prevent hot air from escaping is a necessity. Put simply, the greater your home’s capacity to retain heat, the more you will save on your bills, and the longer the building will last.

Leaking Air Costs Money

Whether the ceiling is finished with plasterboard, planks or some other covering, it is difficult to eliminate all pathways for air that you have paid to heat, from travelling into the space between the ceiling and roof.

Electrical boxes, lights and the joints between ceiling finish pieces have gaps through which air moves. As warm air rises to touch the cooler roof, it rapidly cools, with water vapour condensing, and, if left unaddressed long-term, leading to damp and associated issues, such as mould.

Lost heat, plus mould and rot caused by damp need to be avoided at all costs, as they can quickly compromise the structural integrity of your home; something which is decidedly difficult to fix.

Insulate A Vaulted Ceiling

The problems to be solved are: warm air flow, damp, and heat radiating away from internal areas. Each insulation product has its own qualities and installation requirements

Insulate A Vaulted Ceiling: Key Factors

Expert use of caulk and tape by your contractor can minimise how much air gets through the ceiling, and, consequently, causing irreversible damage

Insulation traditionally has involved fibreglass batts, or blankets, installed between the horizontal rafters in the attic leaving substantial air space below the sloped roof. The batts reduce the flow of air from the home below and the large air space in the attic allows adequate ventilation to keep damp from being a concern.

The batts of insulation must be thicker in the attic than in the walls because of the greater potential for heat loss. Thicker insulation means more power to insulate.

Vaulted Ceiling Insulation: Consider Your Choices

How to insulate a vaulted ceiling is a bit dicier than adding insulation material to a flat one, as the narrower space between sloped roofs, and sloped ceilings cannot accommodate thicker batts in the way a conventional attic can.

Solutions include pricier, thinner batts, with a higher insulating factor made especially for vaulted ceilings, such as blown cellulose, or, more recently, spray foam insulation-an insulation that was specifically designed with hard-to-reach places in mind.

The problems to be solved are: warm air flow, damp, and heat radiating away from internal areas. Each insulation product has its own qualities and installation requirements.

One of the advantages of fibreglass batts is that they have been in use for a substantial amount of time, and are inexpensive to purchase for appropriate ratings for walls.

However, if long-term effectiveness is your top priority, you’d be better off looking elsewhere; over time, fibreglass insulation becomes far less effective, with fibres coming loose, and compromising it’s overall efficacy as a direct result.

Insulate A Vaulted Ceiling

Cellulose can perform slightly better than batts, due to a higher insulation factor for its thickness, and when blown in a sufficiently compacted amount, it can restrict air movement around it much better

Batt Insulation: Is It Worth It?

Many vaulted ceilings require more expensive, speciality batts to gain the correct insulation factor. Even then, batts allow a good deal of air to pass through and around them where they are not fitted perfectly, or have shifted or settled through time.

More ornately designed roofs aren’t quite so easy to insulate, as they inevitably provide more paths for air to escape from. Electrical wiring and fixtures, or any other interruptions in the straight line from wall to roof peak add to the complexity of using batts.


This product can perform slightly better than batts, due to a higher insulation factor for its thickness, and when blown in a sufficiently compacted amount, it can restrict air movement around it much better.

To insulate a vaulted ceiling using this method, the packing should resist settling, because the material naturally wants to expand to its original density.

Air can still pass through it, and some building requirements demand ventilation between the insulation itself, and the roof. In this instance, or in cases where it’s been less optimally installed, its ability to restrict warm air from escaping is not much better than fibreglass.

Insulate A Vaulted Ceiling

As it expands, the foam seeks out the gaps, cracks, and crevices, and fills them in. After it sets, spray foam insulation forms a rigid, durable barrier to prevent the warm air that’s inside your living area, from exiting through the vaulted ceiling, where it no longer has chance to create damp or mould. The insulation is not affected by water

Spray Foam Insulation

Spray foam insulation consists of two or more compounds, that are combined, and applied by water pressure, in a single pass through an applicator wand at the work site.

As the product is deposited in the wall, ceiling or floor, it expands up to 100 times its original thickness, sealing the cavity completely.

Spray foam insulation also has a much higher insulation factor than either fibreglass or cellulose. Combined with its superior, sealant properties, and protection from damp, you can expect substantial savings on your energy bills.

It can be applied during construction, or injected into the walls and ceilings of existing buildings. To install it, prior expertise is essential; opt for an experienced contractor to ensure that the work is carried out to the highest standard.

Be Comfortable at Home

Rising energy costs should not keep you from enjoying the warmth of your home. The construction industry routinely searches for the best methods to create more energy efficient buildings.

Good methods and good products, used in the correct circumstances, will not just keep you home cosy; they will ensure it remains that way for the life of the construction.

You shouldn’t have to worry about unseen damage. There are a range of products that can provide a solution to the question, “how do you insulate a vaulted ceiling?”

By opting for a professional product, and a licensed contractor to install it, you set yourself up for success from the outset.

Ready to take the next step? Talk to our team of home improvement experts today by calling 0800 1700 636, or, alternatively, by simply clicking the button below!