The layer of insulation traps heat inside the rooms below the loft, so the air within your property stays warmer for longer. It also keeps cold air from outside entering your property. This means you do not have to heat your home as much to achieve the same temperature in each room
How Does Loft Insulation Reduce Heat Loss?
When you heat-up your home, using either your central heating or a fireplace, a lot of that heat will escape through your roof. Heat rises and there is no way to stop it – that’s just science!
Heat escapes through your roof via both conduction and convection methods. Laying loft insulation in the way of this will significantly reduce the amount of heat that passes through your ceiling, into the loft space and out into the open air outside.
The layer of insulation traps heat inside the rooms below the loft, so the air within your property stays warmer for longer. It also keeps cold air from outside entering your property. This means you do not have to heat your home as much to achieve the same temperature in each room.
Across the year, this could potentially save you hundreds of pounds. Now you know the answer to – how does loft insulation reduce heat loss?

When the insulation foam is blown into place, it begins to enlarge up to 100 times in size immediately on impact. It then hardens and sets as an all-encompassing blanket of thick insulating material. Both methods were developed to reduce the amount of heat lost from your roof – decreasing the amount of fuel you use for heating or cooling
The Thicker The Better
The thicker your loft insulation is, the better it will perform. Thicker materials will be a lot more effective at keeping heat from leaving your house. It is just like wearing a coat – the bigger the coat the warmer you’ll be!
There are two common methods of applying loft insulation. The first method is to lay rolled-out pieces (or batts) of fibreglass or wool insulation directly onto the base of your loft. This is a method for lofts that have easy access across the whole platform. Read more about fibreglass type here and why it may not be worth the money and hassle.
The second most common method is to blow loose-fill insulation material in place, using a hose and pressured air like foam insulation. This is good for lofts that are harder to access and those that have lots of little nooks, crannies and crevices that are otherwise hard to reach.