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Joisties | Steel Joists

Joisties | Steel Joists

Underfloor Insulation

Regular price $149.00
Regular price Sale price $149.00
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Tax included. Shipping calculated at checkout.
  • 100% Polyester
  • Made from 45% recycled plastic bottles
  • Not itchy, non toxic, non allergenic
  • Australian Made
  • Returns within 30 days


Improve your floor’s thermal efficiency and help to maintain a comfortable temperature all year round with Joisties. We’ve got you covered!

Innovative Joisties are one of the highest rated underfloor insulation solutions for steel-framed floors. ecoMaster’s Joisties adhere to steel joists to hold insulation in place, and reduce the loss of heated and cool through your floor. They’re Australian-made, non-toxic and easy to install.

If you are living in a steel frame home construction, you have many advantages over a wooden frame.

As you are living in this type of home you are no doubt aware that the steel frame is:

  • 1. Stronger and more durable than it’s wooden frame counterparts due to the steel fabrication being about 30% to 50% lighter than an equivalent wooden frame. Surprisingly, this makes your home far stronger and durable.
  • 2. Highly resistant to fire, as it should be treated with special flame retardant coating. If a fire does occur the coated steel will impede the spread of the fire.
  • 3. Mostly immune to the degrading effects of burrowing, wood eating insects and rodents
  • 4. Usually moisture resistant particularly with a hot zinc and extra powder coating treatment for enhanced rust resistance.

The primary disadvantage is that a steel frame construction is not known for its warmth because of its high efficiency in conductivity. It is very important that insulation is put in place to counteract the thermal conductivity of the steel frame. This means insulation is absolutely essential in the roof, the walls, and underneath the floor.

It’s not easy to insulate a steel frame underfloor – well not until now. ecoMaster’s Joisties has made it easy to make sure you get more than adequate insulation under your floor to stop the air flow and temperature conduction between the inside and outside of your home.

Staying comfy and healthy can be a real struggle as more energy is used to maintain the temperature, so bills can rise rapidly.

Floor insulation is fantastic for stopping air flow and reducing heat loss by around 20%. This barrier is ideal for keeping your home cool in summer too.

But insulating a steel framed floor can be tricky. Insulation can’t be stapled to steel joists so some DIYers use adhesive products which may be messy, dry slowly,last only a short time or off gas. Others try insulating strips to reduce heat and cold transfer via steel.

With more than 20 years of experience installing insulation, ecoMaster has created the ideal solution for installing under steel frame floor insulation.

Joisties are semi-rigid one metre-long boards made from heat-bonded polyester fibres. They’re simple to attach to insulate box or C section steel joists and hold up insulation rolls. Purchase your Polyester Insulation right here, grab your Joisties Fitting Tools and Joisties Adhesive plus a friend to help and you’re ready to start. You’ll be relaxing in comfort in no time!


ecoMaster’s Joisties provide an innovative solution for insulating steel framed floors and keeping your home comfortable.


  • 100% polyester fibre.
  • Heat bonded, with no binding chemicals.
  • Free from formaldehyde or glues.
  • Do not hold moisture.
  • Not affected by mould or mildew.
  • Resistant to rodents.
  • Non-flammable – comply with fire regulations.
  • Can be cut to fit using a sharp utility knife.
  • Simple to install.
  • Manufactured in Australia.


  • One of the highest rated underfloor insulation solutions for steel framed floors.
  • A simple, cost-effective solution.
  • Non-irritant, non-toxic and non-respirable.
  • No itchy glass fibres in your skin, eyes or lungs.
  • Creates a steel frame thermal break under every joist.
  • Can be used on box sections, C section floor joists and C section steel beams.
  • Effectively blocks cold and hot underfloor draughts.
  • Keeps floor temperatures comfortable in winter and summer.
  • Helps to improve your home’s thermal efficiency.
  • Suitable for enclosed and open sub-floors.
  • 50-year durability warranty.



Joisties Each box contains 20 Joisties, which will cover 20 lineal metres of joists
Material Heat-bonded polyester fibres
Joisties dimensions 1000mm x 150mm x 10mm
R-Value Joisties provide the standard thermal break for steel building elements of approximately R0.2
Made in Australia


Always check specifications for this product and watch our 5 Part step-by step installation videos.


How To

Each Joisties board is 1-metre in length. There are 20 Joisties in each box, which covers 20 lineal metres of joists.

First, work out how many Joisties you need. Measure the length of joists in your steel framed floor. Multiply this by the number of joists to get the total lineal metres required. Make sure you check for areas with different length joists.

It’s helpful to draw a diagram showing the length and number of joists in each floor section.

What you will need:

  • Adequate Joisties to cover all joists.
  • Utility knife.
  • Tape measure.
  • Pencil.
  • Diagram with dimensions of floor joists.
  • 2 Joisties Fitting Tools.
  • Joisties Adhesive.
  • Polyester insulation rolls to fit between joists


  • You need at least 40cm of crawl space to install underfloor insulation.
  • Use a sharp utility knife to cut Joisties to length, or to fit around pipes and wires.
  • When trimming Joisties, lay another Joistie over the top of the Joistie to be trimmed, to use as a guide and create a neat square end.
  • Use Joisties Fitting Tools and Joisties Adhesive for best alignment and installation.

How to videos:

There are 5 parts to installing Joisties. We have broken each part out into a separate video to make it as easy as possible for you to undertake your own installation, just like a professional.


Q: What are Joisties made of?
A: Joisties are made of polyester fibres compressed into a firm board. 

Q: What R-Value are Joisties?
A: Joisties provide the standard thermal break for steel building elements of approximately R0.2

Q: Why do I need insulation as well as Joisties?
A: Joisties insulate the steel joists and hold the insulation in place. Joisties do not insulate your floor, they only insulate the joists themselves. You will still need bulk insulation to put between the joists. 

Q: How do I install Joisties?
A: Click the How To tab to watch the installation videos

Q: What’s so special about the Joistie adhesive?
A: The Joistie adhesive has two very important qualities. Firstly, it’s low VOC. This makes it safe to use even in low ventilation spaces. Secondly, it has a very high “grab” so that means that once you stick the Joistie up, it will stay up. That makes it easy to get the job done.

Q: Can I use Liquid Nails instead of your more expensive adhesive?
A: Yes you can but we don’t recommend it. It will be much messier and take much longer.  Liquid nails will not hold up a Joistie straight out of the cartridge. You will need to undertake the “contact adhesive method”. That is, apply the adhesive to the Joistie, stick it up, take it down, allow the adhesive to go tack free, (5 to 10 minutes) and then re-stick the Joistie up.  Also, Liquid Nails is high VOC so is not safe in a low ventilation space.

Q: Must I use your Joistie fitting tools?
A: No, you can fit Joisties without the fitting tools. Aligning the Joisties along the joists so that they support the insulation on both sides of the joist will be much harder without the tools, but it can be done.

Q: How long does it take for the Joistie adhesive to set?
A: We recommend you leave it at least 24 hours before fitting the polyester underfloor rolls.

Q: How can I trim Joisties to length or to go around pipes and wires?
A: Joisties are easily cut with a sharp utility knife. When trimming to length, use another Joistie lapped over the one you are trimming. This will provide you a square guide to trim by.  Rebates are also easily cut using a knife.

Q: How many Joisties are in a box?
A: Each box contains 20 Joisties. Each Joistie is 1m long so one box will cover 20 lineal metres of joists.

Q: How can I work out how many Joisties I will need?
A: Each Joistie is 1m in length. Measure the length of the joists and multiply by the number of joists to get the total lineal metres required. There will likely be sections of your floor with different length joists. It’s a good idea to make a sketch and write on your drawing the length and count of joists in each section of floor.

Q: How do I know how much adhesive I will need?
A: One cartridge of adhesive is enough for about 30 Joisties if you follow the recommended pattern of adhesive. It’s prudent to order an extra tube just in case you over apply adhesive.

Q: Are the powerful magnets on the fitting tools safe?
A: Under normal circumstances the magnets are safe. If you have a pacemaker or other bodily electronics or artificial joints it’s best to check with your medical professional first.



How are Joisties shipped?

Joisties, Joisties Fitting Tools and Joisties Adhesives are normally dispatched via Australia Post. Usually this takes about a week but can take longer. It’s best to plan ahead.

If you live in Victoria and ecoMaster is delivering your Underfloor Insulation then we can also deliver your Joisties at the same time. 

Where  can you deliver to?

Delivery via Australia Post is available to most locations with the exception of the Northern Territory and very remote areas.  If in doubt, give us a call on 1300 326 627 or contact us here

Can I collect?

Please click this link for the Click and Collect details.


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