How to insulate an attic: step-by-step DIY guide

A well-insulated attic keeps the heat in during winter and stays cooler in summer. With careful preparation and the right protection, attic insulation is a job many DIYers can do themselves. In this blog you will read the steps, what you need and where you are better off calling a professional.

⚠️ Insulation material releases fibres and dust, and in an attic you often work bent over, at height and in a cramped space. If there is damp, mould, doubt about the roof structure or you suspect asbestos-containing material, stop and call a qualified specialist. Calling in a professional is never superfluous.

What do you need to insulate an attic?

Which materials do you need?

• Insulation material that suits your roof or floor, following the manufacturer's advice.
• pressure flange for insulation fixing and insulation fixing pin with metal pin for fixing insulation boards where needed.
• masking film to protect the floor and belongings.

Which tools do you need?

• A tape measure with auto-lock for measuring and a mineral wool cutter for cutting mineral wool to size.
• A cordless drill driver and a stapler for fixing.
• A folding ladder with handle and a rechargeable LED work lamp for safe work with good visibility.
• A construction vacuum cleaner to clear dust and fibres straight away.

Personal protective equipment

• work gloves with nitrile coating, safety goggles and a FFP2 dust mask against fibres and dust.
• knee pads for working on the attic floor.

Preparation

Empty the attic and check that the roof and floor are dry. Look for leaks, mould and damaged beams. Measure the spaces between the beams or purlins and work out how much material you need. Provide good light and lay down boards so you do not step through the ceiling of the floor below.

Step by step: how to insulate an attic

1. Seal gaps and seams and make sure pipes and cables are neatly and safely routed.
2. Cut the insulation slightly wider than the space, so it fits snugly without being compressed.
3. Place the insulation between the beams or purlins without gaps or lumps.
4. Fix boards where needed with insulation fixing pin with metal pin or pressure flange for insulation fixing.
5. Finish the insulation with the foil or finishing layer the manufacturer prescribes.
6. Clear dust and offcuts straight away and check the finish.

💡 Work in long-sleeved overalls and take regular breaks outside the dust. Mineral wool can make you itch.

Common mistakes

• Compressing the insulation, which makes it work less well.
• Leaving gaps and seams open.
• Working without a dust mask and gloves.
• Forgetting ventilation and moisture control.

Working safely

Wear a dust mask, gloves and safety glasses and make sure there is enough light. Use a sturdy ladder and walk only on beams or boards. You can read more about safe working in our blog on safe working on the construction site. Want to get the house ready for winter too? Read our blog on getting your home ready for winter. For accurate measuring, see our blog on tape measures and measuring tools.

Frequently asked questions

Can I insulate an attic myself?

Yes, if you can work safely and the roof structure is dry and in good order. Follow the manufacturer's instructions.

When should I call a professional?

With damp or mould, a leaking roof, doubts about the structure, suspected asbestos or if you simply want to be sure everything is right.

What protection do I need?

Gloves, safety glasses, a dust mask and long-sleeved clothing.

Read also: How to get your garden ready for winter

Read also: How to check your roof after a storm

Where can you find everything for this job?

At Saniso, the online store for DIYers and professionals, you will find tools, materials and personal protective equipment for your job.

• Browse our construction tools and our workwear and safety.
• Create a customer account and order easily.
• Working on a bigger project or want to hand over the job? Request a project quote.
• Book a showroom visit, at least 24 hours in advance.
• Not sure which material suits your job? Get in touch with us.

In doubt about the approach? Feel free to call in a professional.

Saniso – Build your home with Saniso.