Loft Insulation: The Snugg 2024 Guide

Loft Insulation: The Snugg 2024 Guide (updated January 2024)

Loft insulation is an essential component in maintaining a comfortable and energy-efficient home. Insulating your loft can help to keep your home warm in the winter and cool in the summer, reducing your energy bills and improving your overall quality of life.

In this guide, we cover:

1. How does loft insulation work?
2. What are the benefits of installing loft insulation in your home?
3. What types of loft insulation are there?
4. How much does loft insulation cost?
5. How efficient is loft insulation?
6. Are there any grants or incentives for loft insulation?
7. How is loft insulation installed and maintained?
8. Loft insulation FAQs

How does loft insulation work?

Lofts are insulated to reduce the transfer of heat between the warm air inside and the cold air outside your home. The material used as insulation - whether it be fibreglass, cellulose, rock wool or natural fibre options- creates a layer of thermal resistance that slows down the transfer of heat.

During the winter, heat escapes through the roof without insulation. But with insulation, the heat can be trapped within the home and reflected back into the living space. This results in less heating needing to be used throughout the winter which can result in lower energy bills.

During the summer, insulation helps to keep your home cool by slowing down the transfer of heat from the outside. This reduces the need for air conditioning which can result in lowered energy bills and more comfortable living conditions.

What are the benefits of installing loft insulation in your home?

Some of the benefits of installing loft insulation in your home include:

• Reduces energy bills: By trapping warm air in your attic, loft insulation can help keep your home warm in winter and cool in summer. This reduces the need for heating and cooling which reduces your energy bills.
• Improves overall comfort: A loft that's well-insulated will help keep your home at a consistent temperature. This reduces drafts and cold spots, which can improve the overall comfort of your home.
• Increases home value: Installing loft insulation is a cost-effective way to improve the energy efficiency of your home, which can increase its value.
• Good for the environment: Insulation helps to reduce energy consumption, which can help to reduce carbon emissions and protect the environment.
• Long-lasting: Once installed, loft insulation can last for decades and doesn’t require regular maintenance.
• Variety of options: There are lots of different types of loft insulation available, so you can choose one that best suits your needs and budget.
• Reduces noise: Loft insulation can also help reduce noise from outside, making your home a more peaceful place to live.
• Easy to install: Installing loft insulation is a relatively simple process that can be completed by yourself. But you might want to use a professional installer to make sure the job’s done quickly and effectively.

What types of loft insulation are there?

There are four main types of loft insulation available. Each has its own set of benefits and drawbacks.

Fibreglass

Fibreglass insulation is one of the most popular types of insulation for lofts. It’s made from small glass fibres that are woven together to form a blanket-like material. Fibreglass insulation is easy to install and is a good choice for most types of lofts.

Cellulose

Cellulose insulation is made from recycled paper products, like old newspapers. It is a more eco-friendly option than fibreglass insulation, but it can be more difficult to install.

Rock wool

Rock wool insulation is made from volcanic rock. It’s fire resistant, making it a good option for homes in areas with a high risk of fire.

Sheep’s wool

Sheep’s wool insulation is made from natural sheep wool fibres. It’s an environmentally friendly choice, since it’s renewable and biodegradable. It’s also great at regulating humidity. But it’s often more expensive than other options.

Plant-based

Plant-based insulation uses materials like hemp, flax and cotton. It’s another environmentally sustainable option, and it also has great breathability and moisture control. It’s another more costly option, however, and it’s not stocked by as many retailers as more common materials like fibreglass or rock wool.

How much does loft insulation cost?

The cost of loft insulation can vary depending on a number of factors, including:

• the type of insulation used
• the size of your loft
• the location of your home

The cost of loft insulation in the UK can range from around £720 to £1200, depending on the house type¹. This cost includes materials and labour.

Insulation material costs can vary depending on the type of insulation used. For example, fibreglass insulation may be cheaper than rock wool insulation.

Labour costs can also vary depending on the complexity of the installation, such as the size of the loft, the type of insulation used, and the location of the property

Sign up to Snugg to find out whether your home would benefit from loft insulation and get quotes from local installers.

Are there any grants or incentives for loft insulation?

A grant is money given to you that you don’t have to pay back.

There are several grants available in the UK that could help you pay for loft insulation. You can find an up-to-date list of available grants on our grants page.

How efficient is loft insulation?

Loft insulation is a highly efficient way to improve the energy efficiency of your home.

The efficiency of insulation is measured by its R-value, which is a measure of its thermal resistance. The higher the R-value, the more efficient the insulation. Loft insulation is typically recommended to have an R-value of between 6.1 and 7.

In the UK, the government recommends that loft insulation should be at least 270mm deep which would roughly equate to an R-value of 6.1 (for fibreglass insulation). You’d need to install fibreglass insulation roughly 310mm deep to achieve an R-value of 7.

The efficiency of insulation can also be affected by gaps and air leaks in the insulation, which can allow warm air to escape. To maximize the efficiency of your insulation, it's important to make sure that the insulation is installed properly, without any gaps or air leaks, and that it’s maintained in good condition.

How is loft insulation installed and maintained?

The process of installing loft insulation is relatively simple. But be sure to follow the manufacturer's instructions and take proper safety precautions if you decide to install loft insulation yourself.

1. Measure the loft space: How much insulation you need depends on how much space you have in your loft.
2. Prepare your loft: Take out old insulation, clean the space, and fix anything that needs fixing.
3. Install the insulation: There are two main ways to install loft insulation:

1. Laying insulation between the joists: This is the most common and easiest way to install loft insulation. Simply measure the space between the joists and cut the insulation to fit.
2. Blowing insulation into the loft: This method involves using a machine to blow insulation into your loft. It's quick and easy, but it can be pricey.

You'll need to cover your loft insulation with a protective layer once it's installed. You can do this with a vapour barrier or insulation board. By doing this, you'll keep the insulation in place and prevent it from getting damaged.

Loft insulation FAQs

Which loft insulation is best?

The most common types of loft insulation include fibreglass, cellulose and rock wool.

The best insulation will be the type of insulation that’s most suitable for you. For example, if you want to install the insulation yourself, you might find that fibreglass is the best type for you since it’s the easiest to install.

Which loft insulation is most sustainable?

The most sustainable types of loft insulation are sheep’s wool and plant-based insulation. Both are made from natural, renewable materials, with plant-based insulation containing hemp, flax or cotton.

Both types of insulation are biodegradable, further reducing their overall environmental impact.

How much loft insulation do I need?

The amount of loft insulation you need will depend on the size of your loft and the R-value that you’re trying to achieve. The recommended R-value for loft insulation in the UK is between 6.1 and 7. So if you install fibreglass insulation, you’d need it to be between around 270mm and 310mm thick.

Is loft insulation dangerous?

Loft insulation is generally considered safe and shouldn’t pose a risk. But it’s important to follow proper safety precautions when installing insulation, such as wearing protective gloves and goggles to avoid contact with your skin or eyes.

Insulation can be dangerous if it’s not installed correctly or if it comes into contact with electrical wiring or other potential fire hazards. Follow the manufacturer's instructions when installing insulation and speak with a professional if you have any concerns.

Some older insulation, especially vermiculite, can contain asbestos which is dangerous if inhaled. If you suspect that your insulation might contain asbestos, it’s important to get it tested by a professional. Do not disturb it or try to remove it yourself.

Is loft insulation fireproof?

Most types of loft insulation, including fibreglass and rock wool, are naturally fireproof. But while cellulose insulation is treated to become fire-resistant and shouldn’t easily catch fire, some firefighters have claimed that cellulose insulation can hide smouldering embers that can potentially reignite after a fire has taken place.

Will loft insulation stop condensation?

Condensation can be caused by poorly installed insulation or poor loft ventilation. If there are any gaps in your existing insulation, plugging these with extra insulation could minimise the warm air rising up into the colder loft and releasing moisture when it comes into contact with the cool roof surface. But you’ll need to make sure that the loft is properly ventilated so that any moisture has a chance to escape.

Where to buy loft insulation?

Loft insulation can be bought from specialist online retailers and from hardware stores. Some popular stores in the UK that sell loft insulation include:

• B&Q
• Jewson
• Travis Perkins
• Wickes

Will loft insulation make a difference?

Loft insulation can make a significant difference in terms of your home’s energy efficiency and comfort. It’ll help you feel warmer in the winter and cooler in the summer, reducing the need for heating and air conditioning, which can lead to lower energy bills.

But loft insulation is only part of the solution to keeping your home energy efficient. You’ll also need good floor, wall and window insulation to keep your home warm.

When to replace loft insulation?

So long as it’s installed correctly, loft insulation should last for over 40 years.

There are a few ways to tell when your loft insulation needs replacing:

• The insulation has been in place for over 40 years
• The insulation material is sagging or settling
• There’s visible damage, such as holes, tears, or mould
• You can feel drafts or cold spots in the loft

Is loft insulation free for pensioners?

If you receive a pension, you may be able to get a government grant to help fund the cost of loft insulation. See our grants page to check whether you’re eligible.

Is it a legal requirement to have loft insulation?

Since 2006, the UK government’s building regulations have required all homes to be built with loft insulation that’s at least 270mm deep. This also applies if you’re renovating your loft.

If your roof doesn’t already have loft insulation, you’re not breaking the law. But you’ll want to consider installing loft insulation (at least 270mm deep) to improve the energy efficiency of your home.