Do you want to learn how to insulate a loft? Reading our useful guide will cover not only how to insulate a loft but also loft insulation do’s and don’ts, the tools you need to complete the job, and how to stay safe while doing so.
What Does It Mean to Insulate a Loft?
Insulating your loft is the process of adding insulation to the loft space walls, floors and ceilings to help trap heat. As heat rises, having good insulation at the top of the house is important so it doesn’t all escape. Insulating your loft should be a straightforward process providing it is accessible, and there are no issues with dampness or condensation. While you can hire a professional to insulate your attic, you don't need any special skills or tools, so many choose to do this themselves
Which Type of Loft Insulation Should You Choose?
Rolls of mineral wool insulation are a common choice for those with regular loft joists. The insulation can be rolled out between joists in layers. The primary layer is placed between the joists, with a second layer added perpendicular to this, covering the joists and ensuring that the insulation is at the correct depth.
An alternative method is warm loft insulation. Here the insulation is fitted between and over the rafters, rather than between the joists. For this process, rigid insulation boards are cut to size and slotted in, or foam insulation can be sprayed between the rafters. However, this is not a job recommended for someone without experience, and you will likely need to hire a professional to help you, should you choose this method.
Other common materials include sheep wool, polystyrene, natural fibres, thermal insulation boards and reflective foil insulation.
Why Insulate Your Loft?
Insulating your loft space comes with many benefits, such as:
- Significantly lowering your energy bills
- Helping to keep your home warm
- Being kinder to the environment
- Quick and easy installation
An uninsulated loft can lose over a quarter of the heat generated within your home. If it is not insulated correctly, the hot air rises to the roof's top to easily escape. This can lead to a vicious and expensive cycle of constantly losing heat and needing to turn the heating on to replace the warm air that's been lost. Having to keep your heating on in colder months to stay comfortable can lead to costly energy bills; it also sucks the moisture out of the air and can cause dehydration, dry skin problems, and even sinusitis.
Insulating your loft, attic, or roof space is a simple and effective solution to trapping air in the home. It is also very long-lasting, with good quality insulation having a 40+ year lifespan. The savings you'll make on your energy bills over this period means that insulating your loft pays for itself and saves you money year after year. Investing in loft insulation can save you money in the long run, and because you’ll be consuming less energy, you’ll be helping reduce your carbon footprint too.
Insulating a Loft with Boards
Materials Needed:
-
Insulation boards (e.g. PIR, rigid foam boards)
-
Tape measure
-
Utility knife or saw
-
Safety goggles and gloves
-
Adhesive or screws (as required)
-
Sealant or insulation tape
-
Wooden battens (if necessary)
-
Dust mask (for protection)
Steps:
-
Preparation:
-
Clear the loft space of any obstructions.
-
Check for any damage, such as leaks or structural issues, and repair as necessary.
-
Measure the Loft:
-
Use a tape measure to determine the area of the loft and the spacing between the joists.
-
Cut the Insulation Boards:
-
Using the measurements, cut the insulation boards to size with a utility knife or saw.
-
Ensure a snug fit between joists to minimise gaps.
-
Fit the Boards Between Joists:
-
Place the boards between the joists, making sure they sit flush.
-
If necessary, trim the boards for a perfect fit.
-
Secure the Boards:
-
Use adhesive or screws to fix the boards in place, depending on the type of insulation and manufacturer’s instructions.
-
Seal the Joints:
-
Apply insulation tape or sealant to the joints between boards to prevent air leakage.
-
Add a Second Layer (Optional):
-
For additional insulation, you can add a second layer of boards perpendicular to the first layer.
-
Fix wooden battens over the joists if additional structural support is needed.
-
Finish:
-
Ensure all gaps are sealed and the boards are securely in place.
-
Lay loft boards or flooring over the insulation if the loft will be used for storage or as a living space.
Insulating a Loft with Mineral Wool
Materials Needed:
-
Mineral wool rolls or batts (glass wool or rock wool)
-
Tape measure
-
Utility knife or large scissors
-
Protective clothing, gloves, and goggles
-
Dust mask
-
Wooden battens (if necessary)
-
Staple gun or insulation netting (optional for securing)
Steps:
-
Preparation:
-
Clear the loft space of any debris or obstacles.
-
Inspect the loft for any issues, such as leaks or damaged areas and repair them.
-
Measure the Loft:
-
Measure the distance between the joists and the total loft area to determine the amount of mineral wool needed.
-
Unroll the Mineral Wool:
-
Unroll the mineral wool and let it expand to its full thickness.
-
Cut the Mineral Wool:
-
Cut the wool to the required length using a utility knife or large scissors.
-
Ensure pieces are slightly wider than the space between joists to ensure a snug fit.
-
Lay the First Layer Between Joists:
-
Start at one end of the loft and lay the mineral wool between the joists.
-
Push the wool gently into place, ensuring there are no gaps.
-
Lay a Second Layer (Optional):
-
If additional insulation is needed, lay a second layer of mineral wool across the joists (perpendicular to the first layer).
-
This layer should cover the joists completely to reduce thermal bridging.
-
Secure the Insulation (Optional):
-
Use insulation netting or a staple gun to secure the mineral wool in place if needed, especially for vertical surfaces.
-
Check for Gaps:
-
Inspect the insulation for any gaps or compressed areas and adjust as necessary.
-
Finish:
-
Once the insulation is in place, you can cover it with loft boards for storage or leave it uncovered if the loft will remain unused.
By following these steps, you can effectively insulate your loft, improve your home’s energy efficiency, and reduce heating costs.
Further Considerations For Insulating Your Loft Before You Begin
Storage
Using your attic space for storage can be very handy. However, to do so, boards will be placed between the joists. If there are boards already in your loft or plan to do this, you will need to raise the floor level before insulating. This is so you can fit enough of the insulation between joists to make it useful. When raising the floor, make sure that there is ventilation between the insulation and the boards to ensure that condensation doesn't build up underneath the boards and cause damp and rot problems. The insulation shouldn't be squashed down either, as this will negatively affect its ability to prevent warm air from escaping.
An Additional Room
If you plan to use the loft or attic as an additional room in your home, then the walls between the room and the unheated space must be properly insulated. Otherwise, the room will be extremely cold. You can insulate sloping ceilings and vertical walls in much the same way as you would a warm roof with an additional layer of plasterboard inside the insulated area. If the ceiling is flat, this can be insulated in the same way as a regular loft. This should be done by a professional.
Hard-to-Access Spaces
Suppose your attic or loft isn't easily accessible. In that case, it is possible to hire a professional who will use special tools to blow the insulation into the right spaces to be effective. Options for insulation materials using this method include mineral wool fibre, treated cellulose, or polyurethane foam.
Flat Roofs
While insulating a flat roof from underneath can be done, this may lead to condensation issues. Therefore if you want to insulate a flat roof, it is best to tackle this from above. Rigid insulation boards can be put on top of the roof, either on the timber roof surface or the weather-proof layer. Timing this for when the flat roof needs replacing can be the most efficient way of doing this as now insulation must be completed in line with building regulations.
Cold Lofts
Because insulation acts as a barrier between warm living spaces and the colder roof area, installing insulation will make your loft space colder. If you already know of damp problems in the area, it is vital to consider adding additional ventilation so as not to worsen after the insulation has been installed. Fixing damp problems before insulating is the best course of action.
It is also essential to be aware of your water tank and pipes, which could freeze in the colder space. Insulating around the pipes and tank will prevent this from occurring. Cold draughts could also escape into your home via the loft hatch, so adding some material around hatch edges to avoid this is also a good idea.
Final Thoughts for Insulating Your Loft
Remember, insulating your loft yourself can be a great DIY project. However, this is only a smart move if you are confident about the job, can access your roof space easily, and aren't aware of any problems that could make installation difficult. Our tips and guide on how to insulate your loft are only a guide, it's always best to employ a professional's help and can find a list of experienced professionals who follow a strict code of practice via The National Insulation Association.
If you are looking for a cost-effective, safe and convenient way to access your loft, you may wish to consider installing a loft ladder. We stock a huge range of loft ladders from concertina ladders to permanent staircases, space-saving staircases and electric loft ladders. Our experienced customer service team can help you find the best loft ladder for your needs so why not get in touch with us, or browse our range today!
