A ground level deck must be laid on a firm, even, level surface.
Mark the site with string and pegs and remove any turf and vegetation – take care not to disturb any drains or underground cables. Level the earth with a rake and spirit level.
To stop grass or weeds from growing through, lay landscaping membrane (which looks like black fabric and comes on a roll) over the site.
The frame needs to be lifted off the ground slightly to stop it rotting. Place bricks or concrete blocks on the ground in the corners and evenly spaced along the sides and check they are level. Cut out pieces of damp proof course material to cover the top of the bricks to stop water rising and penetrating the wood.
To construct the frame, cut four joists of 150mm x 50mm pressure-treated timber to fit the perimeter of your area and screw together in the corners ensuring all corners are perfectly square. Cut joists to span the framework, treat the cut ends with preservative, slot them in at intervals of no more than 40cm and screw into place. Take care to ensure the frame sits square and level on your blocks.
Lay the first decking board on top of the frame and cut if necessary. Use two screws to fix the board to every joist. If you have a large frame and one board isn’t long enough, have the joins between boards exactly halfway across a joist so both boards are supported and can be screwed to the joist. Stagger the joins across the deck for strength and an attractive finish.
Position the next board leaving a gap of about 3mm (use spacers) and screw in place. Continue until the whole frame is covered.
Add some decking boards as fascia panels to cover the cut ends of the basic frame. Simply cut to size and screw into position.