What Kind of Sand to Use When Paving With Bricks

Sand Is Small Rocks

• Sand is composed of rock, usually quartz, worn by time, wind and water into small grains. It is found in rivers, along oceanfronts, in deserts and in dry areas that once were river or lake beds. While all sand is similar, it varies widely in mineral content and size of grains, from very coarse to very fine. Brick paving projects may require more than one type of sand.

Sand as a Base

• Coarse sand is usually used as a base for brick pavers. It may have grains 1/8-inch or more, although sizes are not uniform. It makes a good base, especially when installed over compacted gravel, because it may be easily leveled and firmed but will still allow water to seep through it into the ground. It is sold by sand companies and home improvement stores as paver sand. Some may have dirt particles mixed in.

Fine Sand Seals Joints

• Once bricks are laid, sweep finer sand into the joints to secure the bricks. The choice of this sand will depend in part on the bricks. Standard bricks are 2 inches thick, street paving bricks about twice that. Street pavers will need coarser and denser sand because they will have bigger joints. Brick installation also will affect this -- those laid tightly together will need finer sand to get into small spaces, those with wider spacing take slightly coarser sand. This is sold as mason's sand or play sand. It has finer and more uniform grains and usually has been washed free of dirt and debris.

Polymers Enhance Sand

• Some sand is enhanced with polymers, synthetic materials which act as binders to hold the sand grains together. It installs like mason's sand, swept over the bricks and into the joints, but then is sealed with water to make it form a tight bond between bricks which resists insects, water erosion and weed growth. It forms a solid joint that retains the bricks but remains flexible enough that it does not crack as the paving surface shifts slightly from rain or freezing.