# Patio - mason sand for subbase issues?



## concretemasonry (Oct 10, 2006)

A proper paver patio installation consists of a compacted base (up to 8" thick) over the subbase. The base material should the same material that is put under an driveway and should be sloped to the grade you want for drainage.

Over the base you need a uniform 1" thick uncompacted sand setting bed (usually concrete sand or coarse mason's sand depending on the local terms). Then sett the pavers and the edge restraints and spread light dose of mason's sand and vibrate with a plate vibrator to even out the surface and draw the sand up into and down into the tight joints to provide a very strong and stable surface.

You did not say whether you had clay pavers or the far more common interlocking concrete pavers and the installation described is the classic method for interlocking concrete pavers.

Compare that to what you have on your hands now.

It must have been a quick, sudden shower because a normal patio can be set in a couple of hours unless the stone setter does not have any help and has to run around for more pavers.

Dick


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## merchant (Aug 29, 2011)

my question was it is okay to use mason sand as sub base and will it withstand rain and snow or will it get very wobly


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## concretemasonry (Oct 10, 2006)

Mason sand cnnot be conpacted in the way most base materials are. When it is damp, it may look compacted, but when it gets dry or wetter it becomes unstable and it can be expected to allow movement.

The installation steps I listed were generalized from the more technical standards that are on the web site for the Interlocking Concrete Paver Institute (ICPI) at icpi.org (I think). These can be relazed a little bit for a patio, but not for a street or a parking lot.

Unfortunately the term "concrete sand" and "mason sand" are variable and regional and they actually overlap in most technical standards. - To answer youe question quickly, mason sand is not an appropriate base.

The only place I would use mason sand would be to spread lightly over the set pavers is because the fineness allows it to be vibrated into the tight joints.

Dick


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## jomama45 (Nov 13, 2008)

If you already have the mason sand, you could use it with OK results IMO, but never more than 1" thick, and it needs to be somewhat uniform.


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## merchant (Aug 29, 2011)

i have called a guy to remove the pavers, remove sand and redo it. Lets hope he will show up.


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