Paving slabs are a relatively inexpensive way to improve backyards or gardens by creating a path, building a patio or forming some other decorative feature. Laying slabs on grass is easy enough for the average do-it-yourselfer to handle, thus avoiding the expense of hiring a contractor, although slabs laid directly on grass may become uneven over time. Slabs come in a wide range of colours, sizes and finishes, giving you plenty of options.
Mark the area to be paved using spray paint or wooden stakes and string. Allow about 15 inches on either side for working space.
Dig the area to a depth of about 3 inches to remove the grass and topsoil. Use a spirit level at various points to make sure the excavation is level. Rectify any areas that are uneven by either filling in or scraping away the soil. You may want to slightly slope your slab surface patio by digging one end about an inch deeper than the other, so that it slopes gradually from end to end, allowing rainwater to drain away.
Mix 6 to 8 parts sand and 1 part cement with water until it does not leak water when squeezed but can be moulded, with the consistency of smooth peanut butter. Spread this throughout the bottom of the excavation in a roughly 2-inch layer and level it with a rake.
Place the first paving slab down in one of the corners and gently tap it into position using a rubber mallet so it's firmly seated in the cement and the edges aren't crooked. Place another slab next to the first, leaving a gap of about 1/2 inch. If you don't have a rubber mallet, use a block of wood between the slab and a metal hammer. Do not hit the slabs directly with a metal hammer, as this can cause damage.
Mix 4 parts building sand with 1 part cement and water to make a mortar. Use a mortar trowel to fill in the joints between the slabs for an attractive finish, bedding down using a pointing bar. Wipe excess mortar off the slabs before it dries. Do not stand on the slabs for 24 hours, and wait for around a week to ensure all mortar and bedding has dried completely before installing furniture. Light use of the patio will not cause any damage after 24 hours.
If you pave next to a home, make sure the level of the paving is no less than six inches below the damp proof course of the house. The damp proof course is a horizontal layer of mortar acts as a waterproof barrier to prevent rising damp.