Wooden Decking in Caithness

• Have a step tread width of 900mm – if you don’t want them that wide, they should be no less than 760mm
• Add a central step riser to stairs wider than 900mm to prevent them buckling
• Add a step depth (the vertical distance between each step) of between 150 and 180mm if building your own riser, so the steps are at a comfortable depth

• Step treads (the actual step themselves)
• Step risers
• Coach screws
• Deck screws
• Saw
• Drill

1. Make sure the ground where you want to put your steps is level and firm. If it’s not, consider laying concrete or paving slabs to provide a secure surface for your steps to sit so they don’t sink.
2. Grab some joist off-cuts and cut them to the same width as your step treads. Attach them to the step risers at the top and bottom using countersunk coach screws.
3. Place the steps against the sub-frame of the deck; if you’ve put slabs down for support, make sure the steps sit in the middle of them. The longest edge of the stair riser should be on the slabs, and the short edge against the deck. Drill pilot holes through the step and sub-frame joist, then screw the step to the sub-frame with more coach screws.
4. After drilling pilot holes, screw the treads into the risers at each end with deck screws.
5. If you don’t want gaps between each stair, you can add joist off-cuts or deck boards. Measure the height and depth of the gap, then screw the off-cut or board into the step riser with two screws at each end.

If your deck isn’t going to be flat to the ground, it’s a good idea to have some kind of balustrade to avoid any tripping. If the gap between the deck and the ground is less than 600mm, use a 900mm balustrade. If it’s higher than 600mm, the balustrade should be 1100mm tall.

1. Start in one corner of the sub-frame and position the first board across the inner joists. You want the deck board in the opposite direction to the inner joists, ensuring that it’s flush with the frame. Position any end-to-end joins between the deck boards halfway across an inner joist so you can screw both boards into the joist for stability. Make sure you keep a gap of between 5-8mm to allow for expansion of the wood.
2. Begin to screw your deck boards to the joists. You’ll need to secure the deck board to every joist is covers along your deck frame. Use two screws for every joist. Mark where you’re going to add your screws, ensuring that they are at least 15mm from the end of the board and 20mm from the outside edges. Drill pilot holes for the screws, being careful to only drill through the deck board and not the joist. Then screw the decking screws into the holes.
3. Continue to screw in the deck boards, ensuring you leave the correct expansion gap. You can stagger the deck board joins across the deck for more strength.
4. Sand down any cut ends if you need to before applying decking preserver to protect the timber from rotting.

1. Calculate the surface area for your decking Multiply the length (L) of your decking area by the width (W): L x W = Decking Surface Area (DSA) in m² 10 x 6 = 60m²
2. Work out the coverage of your deck boards Add your deck board width (DBW) to the expansion gap length (EGL), then add the deck board length (DBL) to the expansion gap width (EGW). Then multiply these numbers. (DBW + EGL) x (DBL + EGW) = Single Board Coverage (SBC) 0.144m + 0.005m = 0.149m 2.4m + 0.003m = 2.403m 0.149 x 2.403 = 0.358m²
3. Calculate the number of deck boards you need Multiply the SBC by 1.1 to allow for 10% wastage. Then, divide the DSA by the SBC. DSA / SCB x 1.1 = Total number of boards required 60m² / 0.358m² x 1.1 = 184.36 boards – so round up to 185 so you’re not left short.