Wooden Decking in Machynlleth

• Paving slabs – old or cheap ones are fine
• Timber for the frame and legs
• Type 1 MOT hardcore

1. Mark out the area as we explain in ‘How to lay decking’. Then, dig to 200mm below where you want to surface of the decking to be.
2. Add a 50mm layer of hardcore and make sure it’s compact.
3. Build the decking sub-frame as we describe in ‘How to build a deck frame’.
4. Lay out paving slabs along the edges and in the centre of the area. This will help to spread the weight of the decking.
5. Set the decking frame on the slabs, checking for high or low points and adding off-cuts of timber where needed. Don’t forget to sand and seal these off-cuts with decking preservative.
6. Add your joists and then the deck boards, leaving the recommended gaps of expansion of between 5-8mm.

1. Place a post in the corner of the frame you created with the pegs and string. Measure and mark out 100mm from each side.
2. Dig out this soil to a depth of 700mm (watch out for cables or pipes). You should have a 300 x 300mm hole. Repeat for the other 3 corners.
3. Using a brick bolster, split a concrete block in two. Put a section of the block in each hole.
4. Get a length of post longer than you need and place one in each hole. You can cut it down later.
5. Create props on each post to hold them in place until you’re ready to add a cement mix. Check that they’re level. When you’re happy that they are, secure them in place with a concrete mix, making sure you create a slope in the concrete so that rainwater runs away from each post. When the concrete is set, remove the props.
6. Create a string line around each corner post and find the centre point between each. Place a timber batten at each point, ensuring that they’re not spaced any more than 1500mm apart.

1. Working from the corner where the deck will be at its highest above ground level, measure and mark on the post where the highest part of the frame will be.
2. Measure from the far side of one post to the opposite and cut sections of joist to size. Line up a piece of joist with the mark you made and temporarily secure it. Factor in a 2mm fall for every metre of decking so rainwater can run off.
3. Secure the frame to the other corner post, ensuring it’s at the right level. Do this for every side of the outer frame.
4. Using 100mm coach screws with washers hanging on the end, secure each end of the four sections of frame.
5. Mark out where the centre of the support posts will be and secure all of these posts to the frame, except the centre post.
6. Add your central support joists. These should run in the same direction as the deck boards will run. You’ll need to measure from the inside of the frame on one side to the inside of the frame on the opposite side. Attach the joist in the same way as you did for the other posts. Repeat so the centre post is in between two sections of frame and secure the posts with concrete.
7. Trim down all the posts to the correct height using a saw.
8. Add your weed-control fabric and weigh down with gravel across the entire area.

1. Measure 400mm from the centre of the outer frame and mark a line. This will be where the first joist is positioned. Repeat at 400mm intervals down the length of the frame – if the last one will be more than 400mm, add another joist to create enough support.
2. Attach a joist hanger to each end of the joist.
3. Place the joist in position so the centre lines up with the 400mm spacer mark.
4. Secure using external grade screws once you’re happy that the joist is flush with the frame.

• 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.