Posts, beams, pipe, sheets, long materials are bread and butter for a lot of tradies and DIYers, but they don’t all load the same way. A length of pipe behaves very differently to a sheet of plaster, and treating them the same is where people get into trouble.

Here are a couple of pro tips for carrying long materials safely.

Low-Profile Loads: It’s About Weight

If you’re carrying long materials with a small footprint, like posts, beams, pipe, they won’t catch much wind. So the main thing to manage is weight and specifically how much of it sits forward of your last mount.

The 10% Rule

As a general guide: for every 10% of extra length past the end of the rack, take 10% off your weight-carrying capacity.

It’s a simple way to keep the leverage on your front mount within safe limits.

Sheet Materials: It’s About Wind

Sheets, plaster, flooring, ply, are a different story. The surface area catching wind is massive, and that puts serious strain on your rack at speed. Three things to get right:

1. Secure it thoroughly: Strap it well all the way along the roof rack, not just at the ends
2. Support breakable materials: Plaster and similar need something underneath to support them along their length so they don’t crack
3. Keep the overhang sensible: For solid materials, don’t go much more than 900mm past the end of the rack to limit the strain on the front

Load Smart, Travel Safe

The key is matching your approach to the material. Low-profile loads are a weight-and-leverage, while sheets are a wind-and-support problem. Respect both, strap properly and keep your overhang in check, and you’ll carry long materials confidently without punishing your rack.