Decks, Patios, Porches and Docks - Installing Pavers gravel vs sand

I am installing pavers in my backyard and am wondering if the gravel base is required. My father-in-law told me I only need to use 4-6 inches of sand, but on most of the websites I am reading they are telling me I should lay gravel first. I live in Southern California where it does not rain very often. Is it ok for me to just use sand and no gravel? What are the consequences. Thanks for any help!

We always mixed the sand with Portland cement, 3 sand to 1 Portland. You don't need gravel and you would only use about a 1/2 to 3/4 inch of the mix I described. Lay 1/2 or 3/4 tubes on the ground. Pour the mix between them and screet it to the proper hight. After you lay the pavers, pour sand over them and sweep it until it goes in between the pavers and fills the gaps.

Some people use a wet mix on the outside bricks instead of the dry mix that I mentioned.

The proper way to install pavers is to have a base compacted suitably for the use. The compacted base surface must be parallel to the finished paver surface. Most pavers are 60, 80 or 100 mm thick.

Spread a 1" later of sand on the base and screed it off smoothly. The sand should NOT be thicker, should NEVER contain cement and is NOT compacted. Concrete sand is ideal.

You should also have an edge resratint (plastic, aluminum, steel or concrete).

Lay the pavers with tight joints and sprinkle fine sand (masons sand or fine concrete sand) over the pavers. Compact with a plate compactor (can be rented) and sweep off the excess sand that does not vibrate into the joints.

This is reaaly the only method recommended for interlocking concrete pavers (the most common type of pavers used). The main variable is the strength/compaction of of the base and possibly the paver thickness, although 80 mm pavers are acceptable for most apllications. This method is recommended for pavers installed for patios, sidewalks, driveways, streets, airport taxiways for 747s and industrial pavement applications.

For details on the selection, planning, installation and maintenance of pavers, go to the Interlocking Concrete Paving Institute site - icpi.org, I believe.

Dick

Why shouldn't it contain cement?

Thanks for all your info! I appreciate it :)

Because interlocking pavers are a flexible paving system, and using stabilized sand creates washouts under the crust.

You could also use crushed slag instead of sand for the base. It compacts better.
There is a sand mixture (Techni-seal) that can be used to fill the gaps instead of sand. It has a polymer binder in it so it hardens. Makes it more waterproof. Ask about it where you buy the pavers. It comes in varied colors to match the pavers. http://www.techniseal.com/
Video http://www.techniseal.com/video/Sand_eng.wmv

There is a good reason for using cement, but this is not one of them. This si not like setting pavers in a rigid concrete slab.

The addition of cement changes the interlocking sand from a high quality interlocking material to weak friable material that will only crack and deteriorate because the proportion, placement and compaction are not realy controlled.

As TS said, a paver surface is a "flexible" (able to move without cracking or failing) pavement that relies on the base strength for vertical support and not like concrete that is a rigid pavement that will crack and must be strong and flexible enough to live with Mother Nature. That is why pavers have performed so well for centuries in colder, harsher climates. The use of high strength interlocking concrete pavers is an extension of the well developed history of pavers that goes back to the 2000 year old Roman roads that are still used.

If you are just doing a patio, that is not so critical as an airport taxiway, so you can get a little bit sloppy.

The treated sand is a bit of a gimmick that gives a short term good feeling. Because it makes joint material more rigid, the eventual temperature and moisture movement will break down the "goop" used to hold it together.

Dick

The treated sand is a bit of a gimmick that gives a short term good feeling. Because it makes joint material more rigid, the eventual temperature and moisture movement will break down the "goop" used to hold it together.

Dick
Our porch was done 5 years ago. Summer to winter temp differences of 110 to -10 and there are no breakdowns in it.