How to install polystyrene insulation

Jason
View the video

How to install polystyrene insulation

View the video
×

Project Overview

Insulating your floor with polystyrene panels is a cost-effective way to help reduce your heating and cooling bills. We show you how to trim the panels to size and install them between your floor joists. You will also see how to use brackets to support the panels in place.
Continue to step-by-step instructions

Step by Step Instructions

1 Prepare your joists for installing the polystyrene insulation
2 Trim polystyrene insulation panels to size
3 Fit support brackets for the polystyrene insulation
4 Trim special shapes in the polystyrene insulation
  • Step 1. Prepare your joists for installing the polystyrene insulation

    Check to see if there is any plumbing or electrical cable installed on the sides of your joists. If you find electrical cable, cover it with wireguard waxed paper. If you find plumbing, cut a gap in your polystyrene panel that leaves 100mm of clearance to allow for future maintenance.
  • Step 2. Trim polystyrene insulation panels to size

    Polystyrene insulation panels come in different sizes to match the standard widths between floor joists. When you find a smaller width, trim the panels to fit the size required. Each panel has accordion edges, so you can easily trim them on either side with a standard trimming knife
  • Step 3. Fit support brackets for the polystyrene insulation

    Place a bracket once every 600mm on both sides of every joist, approximately 60mm below the top of the joist. This will hold the insulation panels in place just below the top of the joist. Nail the brackets in lightly. Then use a panel offcut to confirm your brackets are in the right position before nailing them in fully. Now put your panels in place.
  • Step 4. Trim special shapes in the polystyrene insulation

    Polystyrene insulation panels are easy to trim. For very thin gaps between joists, it is possible to trim the accordion edges on both sides. When the floor joists have an odd shape or overlap one another, you can simply cut a notch out where you need to.
How to warm up your bathroom

Heating & Cooling How to warm up your bathroom The bathroom is where many people start and end their day. Keeping it dry and warm over the cooler months will make stepping out of the shower a little easier and your daily routine more enjoyable.

Use door snakes 02:59

Heating & Cooling How to winterproof your home You can save on your energy bills during winter with some simple D.I.Y. We've got some great ideas on how to winter proof your home to stop drafts and prevent heat loss.

Pet doors 02:54

Heating & Cooling How to create an airtight home To have an airtight home, you’ll need to prevent airflow leaving your home. We’ll show you some places which may leak air and what you’ll need to do to reduce it.

Woman filling small gaps with insulation 01:18

Heating & Cooling How to insulate walls Installing insulation in your walls is a great way to increase energy efficiency and reduce noise. Learn how easy it is to do yourself.

Material for insulating your ceiling 01:31

Heating & Cooling How to insulate a ceiling Keep your home warmer in winter and cooler in summer by insulating your ceilings. We’ll show you all you need to know about installing ceiling insulation.

Person holding an utility knife 03:24

Heating & Cooling How to insulate your home for extreme weather Find out how easy it is to keep your home warm in summer and cool in winter with insulation.

Use a safety screen 05:00

Heating & Cooling How to maintain wood heaters Wood fires are a cosy and economical way to heat your home, but they require regular maintenance. We’ll give you a few tips on what you need to do.

Moisture absorber 03:36

Heating & Cooling How to protect your home from dampness When you live in areas prone to high rainfall, such as the tropics, it’s important to protect your home from dampness and mould. We’ll show you how to do it in a few simple steps.

diy chalkboard cabinet hanging in the garage 01:27

Shelving & Storage D.I.Y. upcycled chalkboard cabinet We take an old cabinet and upcycle it into a handy chalkboard cabinet that will give you somewhere to store tools and a place to write lists or plans for your next project.

honeycomb wall shelves 02:23

Shelving & Storage How to make D.I.Y. honeycomb floating wall shelves These honeycomb floating wall shelves are a modern and stylish way to make a feature of any wall in your house. They’re easy to make and they’ll give a somewhere to show off your favourite things.

bathroom rejuvination 01:44

Ideas & Makeovers Learn how to give your bathroom a makeover on a budget Simple and affordable ways to give your tired bathroom a makeover.

roses in garden

Planting & Growing Winter garden ideas It may be cold outside in most parts of New Zealand but there are still a few things that need to be done in the garden at this time of the year. But if you can’t face going outside, you can always bring your garden inside suggests Bunnings horticul...

diy wood and concrete kitchen island 05:43

Outdoor Living D.I.Y. wood and concrete kitchen island You’d be surprised how easy it is to make this wooden and concrete kitchen island from just a few simple tools and materials.

Modern living room DIY makeover 01:29

Living Room How to give your living room a modern D.I.Y. makeover There are a few simple ways to freshen up a tired living room and make it a real feature in your home. You can create more space by knocking out a wall and updating the furnishings to fit. By adding floating cabinetry and open shelves, you’ll have m...

black diy wooden sofa arm table 02:49

Living Room D.I.Y. wooden sofa arm table A sofa arm table is a great addition if you’re short on space or don’t have a coffee table in your living area.

hampton kitchen

Ideas & Makeovers Hamptons sanctuary Bright, open and stylish are the hallmarks of the Hamptons Sanctuary. The island bench doubles as a workspace and breakfast bar, while the bamboo benchtops and window panel cupboards complete the look.

Top of the content