Project Overview

In this video we show you how to set out a deck. This includes how to measure and mark out the height of your deck. We show you the 3-4-5 rule to make sure your deck is square, and teach you how to run string lines to mark the position of your stumps.
Continue to Step-by-step instructions.
This D.I.Y. Advice is part of a series How to build your deck

Step by Step Instructions

1 Measure and mark out the perimeter of your deck
2 Bolt your temporary timber guides in place
3 Mark out your stump positions
  • Step 1. Measure and mark out the perimeter of your deck

    When making your measurements, it’s important to take into account the height of your decking and joists. In our case, we measured 22mm down from under the sill to allow for the decking and added 90mm to allow for joists – a total 112mm. We then marked this at each end of the sill. We also measure from the ground to this point to establish the height measurement. We then run our string lines at this height around the perimeter of the area. 

  • Step 2. Bolt your temporary timber guides in place

    Bolt your temporary timber guides in place around the perimeter of the decking area. Use your spirit level to make sure these are level. Mark on the timber where the end of the deck is and run a string line across. To check that your deck is square, use the 3-4-5 rule. That means you measure three metres from the sill edge, four metres across the front edge of the deck. Your deck is square when the diagonal line that connects these two points is five metres long.

  • Step 3. Mark out your stump positions

    Refer to your engineering specs to find out how far apart the stumps need to be. For this deck it is every 1500mm. Measure and mark every 1500mm from the sill out to the edge of the deck. Then mark every 1500mm and along the edge. Run string lines to create a grid, each intersecting point on the grid marks where your stumps need to go. Use marking spray paint to mark out these positions on the ground.

Please make sure you use all equipment appropriately and safely when following the advice in these D.I.Y. videos. You need to be familiar with how to use equipment safely and follow the instructions which came with the equipment. If you are unsure, you may feel it is safest to consult an expert, such as the manufacturer or an expert Bunnings team member.

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