top of page

Are you accidentally halving your loft insulation's effectiveness?



Nobody wants to waste money on heating bills, which is why we see loft insulation as being so essential. But is yours performing as well as it could?

A quarter of your home’s heat (so about 25% of your heating bill) is lost through an uninsulated roof *. That’s why so many of us here in the UK make sure that our homes are fully equipped with loft insulation, as it’s a relatively cheap and easy way to save on energy bills. But hundreds of thousands of us across Britain can end up compressing our insulation. If you’re one of them, it might not be saving you as much as you think it is!.

Squashing your insulation reduces its effectiveness by 50%

The vast majority of us in the UK (around 82%, according to the Carbon Trust) use our lofts for storage. That includes most of our customers here at Loft Leg, such as those you’ll see featured in our case studies. This means that insulation often gets squashed under boxes, crates, and suitcases or various other occasional use items. Numerous studies on the topic have indicated that there’s a huge number of Britons who don’t understand why doing this is so problematic. Mineral wool type insulation (the most common loft insulation) needs to retain its full depth in order to work effectively.

One of the most prominent of these scientific studies was performed by the National Physical Laboratory. Their experts tested insulation at the recommended thickness of 270mm, and then compared it to insulation that had been compressed down to 100mm. They found that insulation performed to the manufacturer’s specifications when it was properly installed, but when it was compressed, its thermal resistance was drastically affected.


Thermal resistance of compressed Thermal resistance of uncompressed


insulation 3.09 m2.K/W insulation: 6.11 m2.K/W

As you can see, what seems like a quick fix for giving yourself some extra storage space can end up reducing your insulation’s effectiveness by around 50%, costing you some serious money in bills over the course of a single year. We won’t get too much into the science of it, but basically: thicker is warmer. It’s simple in principle. You wouldn’t want to squash your loft insulation for the same reasons you wouldn’t want to wear a thin coat on a chilly day.

So, if you can’t compress the insulation, what’s the alternative?

Save money and energy by using Loft Leg to board your loft

Thankfully, Loft Leg has been specifically designed to solve this issue.

Essentially, it gives you the means to raise your loft boards by 175mm, allowing you to create a useful platform for storage, while leaving your 270mm depth of loft insulation intact.

Research done in the last few years suggests that just 1 in 10 homes gets the full benefit of loft insulation - so we’ve designed Loft Leg to help you make sure your home is one of them! You can find out more details about Loft Leg on its product page, here.


Loft Leg can be used in conjunction with several other market-leading products we offer, including Loft Lid, all of which can transform the way you use your space.


You can browse them right here on our site, or simply give us a call on 01282 861 001 if you have any questions or need any advice.

We’re here to help!

bottom of page