What’s the Best Loft Insulation?

Ever since I first clambered into our loft as a kid and accidentally touched some exposed loft insulation I've hated the stuff. It was that irritating itchy kind that made me wonder why anyone would keep such a thing in their homes. Of course, back then I didn't know any better and these days I'm well aware of how effective some decent loft insulation can be in your home, although which type is the best?

After that itchy episode I didn't exactly go and research why loft insulation was good, I was more concerned with watching Power Rangers back then, but I've now got a decent idea about the different types and their pros and cons. But first, let’s have a little primer for those who aren't sure about the benefits that loft insulation can bring.

It’s a bit of comforting blanket!

Basically, just think of loft insulation as a nice cosy blanket that lines the floor of your loft. The reason for it is simple; heat rises. The heat that’s getting pumped out by your central heating below will want to find somewhere to escape to, so it will travel upwards and leave your home through your roof. A quarter of this heat is lost without insulation, which will ultimately waste heat and cost you money in the form of higher heating bills in the long run. After all, if you’re constantly losing something then it’s going to cost a lot to replace it, isn’t it?

I know what you really want to know though; just how much money will you save? Quite a bit, as a 270mm depth of insulation can slash around £205 off your annual heating bill. Of course, you won’t initially get these savings back because you’ll have to factor in the cost of insulation in the first place. For a three bed semi-detached home you’re looking at around £200-300 to install, providing you do it yourself as a professional will only had to the cost. So, you won’t be saving money until 2 years in, but given that insulation can last up to 40 years you really are planning for the future when you insulate your home. Plus, when you come to sell then having insulation will add to the value of your home.

It’s not just money either - although if everyone in the UK installed insulation you’d be looking at a saving of £500 million a year – but the environmental benefits are also worth it. The insulation reduces the amount of CO2 that your heating system will send into the atmosphere, and if everyone in the UK it we would save about 2.7 million tonnes of carbon dioxide each year.

The Types of Insulation

Here I'm going to talk about the types of insulation you can buy and the pros and cons of each.

Matting, or blanket/quilt insulation

Image Credit: Bridgewater Surveyors

This is the most popular type of insulation in UK homes and comes in a variety of materials. These flexible rolls can be bought in rock fibre, mineral wool, glass or foil-backed felt. This is the kind of insulation that I had installed in my old house, although not all materials are as irritating to the skin as that one (glass and sheep’s wool are fine). Some are though, so if you’re working with those make sure to wear protection.

The pros here are that it’s easy enough to install yourself, taking little more than rolling out to fit neatly between joists. It’s easy to fit into exposed accessible areas too, such as wall cavities. On the other hand it can be too bulky to fit into small spaces or obstructions in your loft, and if you’re after sheep’s wool insulation be prepared to pay more.

Loose-Fill Insulation

Image Credit: Celbar

Sold in bags, loose-fill insulation is made up of vermiculite, cork granules, mineral wool or cellulose fibre. You can even use newspaper if you want to save some money.

The best thing about loose-fill is its flexibility. You can fill up those small spaces that blanket insulation just can’t get to, so if you've got a loft full of awkwardly placed joists and other obstructions then this is ideal. It’s also good for topping up existing insulation. On the flip side it can come loose if your loft has a draught, and you do need to make sure you’re wearing protective clothing during installation.

Sheet Insulation

This type is used for insulating walls, floors and ceilings. It comes in the form of firm boards; with options for cork, wood and straw board. You can even get boards that are fire and moisture-resistant or even have a decorative covering.

Sheet insulation has some flexibility has it can be ordered pre-cut to specific sizes, although this will cost you more. If you’re doing a loft conversion then this insulation is perfect, and if you cover it with plasterboard you won’t even know it’s there. You won’t miss the benefits though, has it has a high insulating value per unit thickness, but if you’re eco-friendly then you’ll want to know that large amounts of energy are used to produce the boards. Those who are money conscious should also note that it’s one of the most expensive types.

Blown-fibre insulation

Unlike the rest of the insulation types on this list you can’t install blown-fibre on your own, so if you choose this one be aware that you’ll need to hire a professional. He’ll use special equipment to blow insulation into the gaps between joists.

The pros here is that it’s quick and easy for the professional to do, and it’s brilliant for insulating areas where accessibility is a problem. You can also use greener options such as recycled paper and wool. The downside here is that it’s more expensive than the rest, and if your loft tends to be quite draughty then stay away from this one.

At the end of the day, whatever insulation you choose you’ll appreciate the benefits for years to come. Let us know what type of insulation you have in your home (if you do, and if not why not?) and how easy it was for you to install by commenting below.

For information on installing loft insulation have a look at this page.