DIY Guide – Panel Joiners

What types of Panel Joiners are available?

DIY has designed  a range of unique panel joiners to attach the composite panels to each other and to the chassis or frame of your project.

So in addition to the superior strength characteristics of the Composite Panels themselves, our panel joiners are used to create a ‘monocoque structure’ such that the shell shares the ‘loads’ and becomes an extension of the chassis. The result is a product of ‘unbelievable’ strength.

An added bonus is the presence of an aluminium fixing point along each panel, both on the interior – for overhead cabinets etc and the exterior – for awning legs etc.

Click here to view the range of DIY Panel Joiners

What are the key features of DIY Caravans Panel Joiners?

  • Panel joiners are extruded in quality Australian aluminium and available in mill finish or they can powder coated pearl white to match the composite walls
  • Each design includes ‘stops’ so when you assemble the panels you know when they are ‘home’ as there is space for excess adhesive to go, and ‘nibs’ to maintain the depth of adhesive in the joiner.


  • The panel joiners also act as the trim so once the panel is glued into the joiner and excess wiped off – there is no need for further trim or more sealant – leaving a neat and professional look.

How does the DIY Floor Joiner work?

The Panel Joiner – DIY Floor 29  is designed to support the side walls in a very robust way by resting on the the outrigger system of your chassis. Then when the composite floor panel is installed later the joiner is trapped between the floor and the outrigger system creating a very strong joint.

Read this article for details of how to Assemble a Panel Kit for a caravan.

DIY Tip – Ensure your chassis out-rigger system, and rear and front cross members are 3mm LOWER than your chassis rails and other cross members. This will ensure that after you have installed the LHS and RHS walls, the floor will be glued to all  chassis rails, cross members and outriggers in the same horizontal plane.

DIY Caravan panel joiners wall sample with glue

How does the DIY Wall Joiner work?

The Panel Joiner DIY Wall 29-29 is used for joining two 29mm panels together – such as the rear wall and side wall or side wall and roof panel.
DIY Tip – Note this joiner can be installed in 2 different positions.  When supporting the roof use the joiner such that the roof partly overhangs the wall panel (as in this image). To be consistent front and rear walls are also best if they ‘overhang’ the side walls.
ENSURE you have the joiner locations correct before calculating your composite panel dimensions.

Panel Joiner DIY Roof 40-29 is used for joining a 40mm panel (usually the roof) to a 29mm wall panel.
A neat finish is achieved when panel joiners are cut square rather than with a 45 degree mitre (see image). The rear wall panel joiners then go the full height of the trailer and the top can then be sealed with the simple corner caps .

Do the DIY Panel Joiners need painting?

If your joiners are supplied mill finish they will need some treatment to protect them corrosion which may occur if it is exposed to the elements. Most customers have them powder-coated a colour to suit their project design.