Can I put stuff on top of insulation in a loft?

Author: Anais Herzog  |  Last update: Tuesday, March 31, 2026

In general, either batt or rolled insulation or blown loose-fill insulation (fiberglass or cellulose) can be installed on top of old insulation.

Can you put things on top of loft insulation?

It would work fine as long as you don't compress the insulation by putting stuff on top of it. The timber loft boards won't really undermine the insulation as they are a poor conductor of heat themselves.

Can you store stuff in an attic on insulation?

Insulating your attic makes it more energy efficient and can help regulate the temperature, making it more suitable for storage.

Can you put plastic on top of insulation in an attic?

Even if the attic space is unheated, it's typically warmer than the outside air in winter. If you have chosen unfaced batting insulation for your rafters, you should staple sheets of plastic over the batting to accomplish a moisture barrier.

Is it worth topping up loft insulation?

Benefits. A quarter of heat is lost through the roof in an uninsulated home. Insulating your loft, attic or flat roof is an effective way to reduce heat loss and reduce your heating bills. Installed correctly, loft insulation should pay for itself many times over in its 40-year lifetime.

The the wrong and the right way to insulate a loft .

Can I top up my loft insulation?

If your loft is easy to access and has regular joists, you can simply purchase rolls of mineral wool insulation and place a layer between the joists. Then add another layer to cover the joists to your required thickness.

How often should you top up attic insulation?

Fiberglass insulation typically needs to be replaced 15-20 years into it's life, as it can easily become dirty, wet, moldy, and ineffective if there's a roof leak or water damage of any kind.

Is it OK to put plastic over insulation?

Yes, covering your insulation with a vapor barrier plastic before installing drywall is crucial. It prevents moisture buildup that can lead to mold, rot, and even structural damage. A polyethylene vapor barrier also adds a layer of fire protection, making your home safer.

What do you put on top of insulation?

Boards for loft flooring can be installed on top of insulation using plywood, wood, or plastics. Installing loft flooring and boarding over insulation helps save space, prevent heat loss, and increase home value.

Is it OK to cover attic insulation with plywood?

Can I put plywood over insulation in the attic? Yes you can install plywood subflooring directly over the floor joists and insulation on your floor. You need to install rigid insulation boards on top of the attic flooring joists and then install plywood over the top.

Can you put too much stuff in your attic?

Safety concerns: Attics may not be designed to support heavy loads, raising safety concerns about overloading the attic with too many or too heavy items, potentially compromising the home's structural integrity.

Can you put too much insulation in attic?

While loft insulation is an effective way to improve energy efficiency and reduce heating costs, over-insulating can lead to several potential issues. Firstly, over-insulation can lead to poor ventilation in the attic, which can cause moisture buildup and increase the risk of mould growth.

Can you store boxes on top of insulation?

After we've installed your loft insulation, you should not store items directly on top of it. If items are placed on the insulation, it will compress the material down and reduce your insulation's performance by more than 50%, leading to greater energy and heat loss through your roof.

Is it safe to put things in the loft?

When it comes to storing items, it's important to avoid overfilling your loft. If you have a “warm” loft, you can store items that are traditionally not recommended to be kept in lofts, such as documents, food and wine, paint, wooden furniture or valuable artwork.

Can you cover insulation in attic?

If you have exposed fiberglass insulation, it's best to cover it to prevent the fibers from spreading in the occupied areas of your home. Unoccupied or low-traffic areas of your home, like a closed attic, don't necessarily need to have covered insulation.

Can you use too much loft insulation?

Excessively thick insulation can block most ventilation sources, reducing air quality and restricting air exchange within the loft. It can also negatively impact air circulation, which causes respiratory problems and other related health issues.

Can you put things on top of loft insulation without?

Loft boards can be placed over insulation but not directly upon it. Board placed on insulation will compress it and massively impact on its effectiveness. You have to make sure that any loft boarding is at a height that does flatten your insulation.

What can I put over insulation?

What can I use as a vapor barrier?
  1. Elastomeric coatings.
  2. Aluminum foil.
  3. Paper-backed aluminum.
  4. Polyethylene plastic sheet.
  5. Asphalt-coated Kraft paper.
  6. Metallized film.
  7. Vapor retarder paints.
  8. Extruded polystyrene or foil-faced foam board insulation.

Should I remove old loft insulation before laying new?

Should I remove old loft insulation before laying new? Older insulation material will typically need to be removed before adding new insulation. However, in some cases the material may be in good condition, meaning you can simply top up the existing insulation material for a fraction of the cost of a full replacement.

Can I put insulation on top of insulation?

In many cases you can add new insulation on top of old insulation, unless the old insulation is wet, mouldy, or vermiculite. If the old insulation is dry but appears to have previously been wet, you should look for the cause and repair the problem.

What should you not do when installing insulation?

Leaving Too Many Gaps

One of the biggest problems DIY homeowners face is leaving too many gaps in their insulation. Gaps or insulation that isn't secured correctly can leave the building structure open to air and moisture leaks. Spray foam insulation is best for reaching into small cracks and any areas left open.

Do you need a moisture barrier between insulation and drywall?

If you live in a colder climate, you'll be heating your home from the inside to keep the frigid weather at bay. That means most of the humidity will be generated from within, so the barrier should be installed between the drywall and the insulation.

How do you tell if your attic is properly insulated?

Looking across your attic, if the insulation is level with or below the attic floor joists, you probably need to add more insulation. If you cannot see any of the floor joists because the insulation is well above them, you probably have enough, and adding more insulation may not be cost-effective.

Should I top up loft insulation?

According to Home Energy Scotland, an uninsulated home loses a quarter of heat through the roof. And even if you already have some insulation in place, topping up your loft insulation can make a big difference.

How many years does attic insulation last?

Conclusion. Attic insulation can last 80 to 100 years, though it loses its energy efficiency benefits with time.

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