About Joist Supports


Click Here for USA Adjustable Joist Support

The KlevaKlip Adjustable Joist Support AJH45G (Aus/NZ) is now available in a “full kit” form – AJ45KIT – containing all your bolts, nuts and concrete fixings – making this product even easier to useSee below for details:

What is the KlevaKlip Adjustable Joist Support AJ45KIT & AJH45G (Aus/NZ)? AUSTRALIAN PATENT 2012261552 - United States 14/098253

Watch our Adjustable Joist Support (Aus/NZ)Install Video

 Download AJ45KIT Brochure  

 Download AJH45G Brochure

 Download Graph "How to achieve joist heights using KlevaKlip Substructure Products" 


The Adjustable Joist Support has been designed specifically to enable decks to easily be built over concrete slabs in areas where limited ground clearance is available. It is ideal for use when the step-down from your door to your concrete slab is between 100mm (minimum) and around 220mm (maximum). For exact heights please see our Minimum and Maximum Top of Joists Height information or "Heights achieved" grid (both listed below) using 60mm,100mm & 120mm M10 bolts and 70,90, & 140 x 45mm joists.

The AJ45KIT & AJH45G has been specifically designed to be used with 45mm wide treated pine timber joists for the Australian & New Zealand markets.


​360° view Adjustable Joist Support Assembled


Adjustable Joist Support in Action 



Click to enlarge 

How is the Product Purchased?

There are now two options  available when purchasing the Adjustable Joist Support- either the Adjustable Joist Kit which includes Bolts, Nuts, Washers and dynabolts or the Adjustable Joist where they are not included.

Option 1: Adjustable Joist "Kit" (AJ45KIT): Now Available 

The product comes in boxes containing 16 joist supports,16 base plates, 32 x 100mm M10 hex bolts,64 x M10 hex nuts, 32 x M10 washers and 16 x 12 mm Dynabolts.

Option 2: Standard Adjustable Joist (AJH45G):

The product comes in boxes containing 24 joist supports and 24 base plates.(see photo below) Bolts, nuts, washers etc.are purchased separately from your hardware store/merchant depending on what height you want to achieve.

Each Adjustable Joist Support ( joist holder + base plate) requires 2 x M10 Hex Head Bolts, 4 x M10 Nuts & 2 X M10 washers, 1 x 12mm x 50mm Galvanised 12mm dynabolt or x 10mm x 60mm masonry bolt or similar.


Differences between Adjustable Joist "Kit" (AJ45KIT)verses Standard Adjustable Joist Support (AJH45G)?


  • Easy sourcing – box contains everything you need to build your structure
  • Fully threaded 100mm length bolts provide maximum adjustability to cope with your required height and any irregularities in your concrete
  • Easy for the retailer – no special ordering or calculating of bolts etc, and no problems regarding thread length of stocked bolts


  • All Kit bolts supplied are 100 mm length – sometimes customers require 120mm length bolts. They should purchase AJH45G and purchase the bolts,nuts etc separately.

  • For top of joist height below 106mm, customers may need to cut off the portion of the bolt protruding above the joist (relevant for 70mm joists)


      AJ45KIT- How Packaged in box            AJH45G- How Packaged in box

         16 Base Plates & Joist Supports                             24 Base Plates & Joist Supports

     Includes: Bolts, Nuts,Washers & dynabolts Excludes: Bolts, Nuts,Washers & dynabolts or masonry bolts           





 Advantages of the Adjustable Joist Support 

  • Keeps your joists off the concrete and free of unwanted moisture ingress. This Prevents Joist-Rot Through The Bottom Of Your Joists.
  • Is Ideal For Use On Area Where The Concrete Has Built In "Fall" - To Provide A Level Deck.
  • Quick and easy to use - purpose-built for the application
  • Gives a neat, professional look across your deck structure without resorting to various different packers and brackets to achieve your end result   
  • Uses standard M10 10mm hex head bolts, Nuts,Washers and 12 mm dynabolts or 10 mm masonry bolts either supplied in AJKIT or purchased separately from  your Hardware Store/Merchant if you are using the AJH45G.

Minimum and Maximum Top of Joist Information

Minimum top of joist heights

76 mm – fixing joist bracket direct to concrete no base-plate no bolts and using 70mm joist


86 mm – using Joist Support KIT- lowest height achievable using base-plate, 100mm bolts and joist bracket with 70mm joist

86 mm – using Adjustable Joist Support- lowest height achievable using base-plate, 60mm bolts and joist bracket with 70mm joist


106 mm – using Joist Support KIT- lowest height achievable using base-plate, 100mm bolts and joist bracket with 90mm joist

106 mm – using Adjustable Joist Support - lowest height achievable using base-plate, 60mm bolts and joist bracket with 90mm joist


Maximum top of joist heights

150 mm – using Joist Support KIT,100mm bolts & 90mm joist

170 mm – using Adjustable Joist Support, 120mm bolts & 90mm joist


180 mm – using Joist Support KIT, 100mm bolts & 120mm joist

200 mm – using Adjustable Joist Support, 120mm bolts & 120mm joist


200 mm – using Joist Support KIT, 100mm bolts & 140mm joist

220 mm – using Adjustable Joist Support, 120mm bolts & 140mm joist

Note – the above information is a “practical” rather than an “absolute” document. There will be a number of ways to achieve the heights mentioned with different sized joists, however the installer should always be mindful to operate within the KlevaKlip product parameters and relevant joist span tables 

"Heights achieved" when using 100mm for AJ45KIT, 60mm & 120mm long M10 Hex Head Bolts for AJH45G Adjustable Joist Supports (Aus/NZ)? 

Note: All measurements for 60mm &120mm are based on using Galvanised Zenith brand M10 hex head long-threaded bolts.

 Adjustable Joist Type Hex Head Bolt Length Min Height to Bottom of Joist Max Height to Bottom of Joist Min Height to Top of 70/90mm Joist Max Height to Top of 70/90/140mm Joist


Joist "Kit" (AJ45KIT)

100mm 16mm 60mm 86* / 106mm 130 / 150 / 200mm

Standard Adjustable Joist


 60mm 16mm 20mm 86 / 106mm  90 /110
120mm 18mm 80mm 88* / 108mm 150 /170/ 220mm
**No Bolt 6mm 76 / 96mm

* If using long bolts at low heights, to prevent the bolts protruding past the top of joist, the end of the bolt will need to be cut off.

** When Using Joist Support Only.

Span requirements for base- plate positioning for AJ45KIT & AJH45G (Aus/NZ)

All based upon "continuous span" with joists at 450mm between centre's.  

      Joist Size Recommended Span (mm) Maximum Span (mm)
70 x 45 MGP10 800 1200
90 x 45 MGP10 1000 1500
90 x 45 MGP12 1200 1600
*120x45MGP10 1200 1800
*140x45MGP10 1200 1800

 * Joist span limited by lateral loading on bolts

​Typical "Top of Joist" heights achievable with Decking Sub-Structure Products


 Download Min & Max Top of Joist height Information PDF