Is your loft insulation the size of a sprat or a mackerel?
The difference could be costing you thousands.
But don’t worry, you’re in the right place to sort it.
In just a few steps you could have a cosier home and lower bills.
DIY guide to insulating your roof
Our homes in Devon are some of the oldest and leakiest in Europe. With energy bills rising, homes with poor insulation will pay an average of £1,000 more for their heating this year, according to some energy experts.
The good news is loft insulation can be installed or improved relatively easily and cost-effectively with a little DIY know-how or the help of a local handy person.
Before you get started
You’re going to need to:
1. Check for any other issues in your roof space. If you have damp, a leaky roof or any pest issues, you need to get these sorted first. It’s worth consulting a specialist.
2. Make sure you’ve got health and safety covered. Consider:
- Loft access – you’ll want a sturdy (ideally fixed) ladder and if possible, someone to help.
- Suitable protective clothing and equipment (goggles, gloves and face mask are the absolute basics).
- Loft preparation – you may need to move things around or even empty it.
- Laying the insulation out – you’ll need boards to stand on and equipment for the task. This handy guide to safety and equipment will give you some pointers here.
Sizing up the job
Next you need to work out what you’re dealing with. Have you got any insulation already? How deep is it and what state is it in? Are there any lights and wires to consider? Do you want to store things up there? Lastly, you’ll need to measure up.
You’ll want a tape measure, pencil and paper and perhaps your smartphone to take pictures that you can refer back to. Once you’re safely in the loft:
- Measure how deep your insulation is. Remember, you want at least 270mm to ensure it’s properly insulated. This is usually met through layers – a first or ‘base’ layer that fits between the joists (100mm) and a second layer on top to bring it up to the required depth (at least 170mm).
- Check the state of your insulation – if it’s squashed, slumped or in any way damaged, you may want to replace it. The more insulation has been compressed the less good it is at insulating.
- Measure the width between your joists – this is typically 400mm or 600mm. This is important so that you can work out what roll width to buy.
- Scan around for lights. Do you have downlights or pendants? With downlights you’ll need some firesafe covers to protect them, which are easy to fit.
- Check for wires. You’ll want to put them on top of any insulation to avoid overheating, so carefully see if you’ve got enough slack. If in any doubt or the wiring looks complicated, ask your electrician who can extend wires or advise.
- Suss out pipes and water tanks. You will want to insulate these too as your loft will be colder once insulation is fitted
- Assess your loft hatch – does it fit snuggly and block out draughts? If not, it’s a good idea to replace it and put in a loft hatch draught seal.
- Measure up to get the dimensions of the loft space (length and width). If access is an issue, you can always measure the ceiling area of the floor below.
1. Storage vs ease of installation
The simplest solution for installing insulation is using quilted blanket rolls. If storage is essential, you may want to consider loft boarding and there are a number of different solutions including loft legs and insulated loft boards. DIY Doctor offers guidance as well as many other reputable DIY stores.
2. Choosing your blanket loft insulation
You have a number of options to choose from including:
- Glass/mineral Wool rolls – this is the traditional option and highly cost-effective
- Encapsulated / Space blanket (foil backed) – clean and easy to lay but a little more expensive
- Sheep’s Wool – one of the most eco-friendly options, non-irritant and entirely breathable, but you have to cut it to size and it’s likely to be more expensive
- Plastic Wool – made from recycled plastic this is eco-friendly and non-irritant
Create a shopping list
Shop around for the best deals or visit a local DIY store. Your list will want to include:
- Rolls of insulation (by now you know the width and volume and can use a calculator to work out how many rolls you need as well as the appropriate roll widths)
- Saw, craft knife or scissors (if you don’t already own them)
- Insulation guards (if needed)
- Goggles, gloves and mask (always check the health and safety requirements)
- Walkboard (if you don’t have anything suitable)
- If replacing your loft hatch, look for a ‘Part L’ compliant loft hatch one to ensure it is really well insulated.
How to lay and fit loft insulation
There are lots of helpful videos to guide you with handy hints and tips. A video helps you see exactly how it works.
- Start in one corner of the loft and work back towards the loft hatch.
- Don’t forget to leave at least a 25mm gap away from the eaves for ventilation to help prevent condensation.
- Fill any gaps between your living area and the loft to prevent hot air escaping into the roof which can cause condensation.
If you don’t think DIY is for you, check out the National Register of Installers to find a reputable company to help.