Sandstone flag Q

[MFortie]

Hi All,

New to this forum, but am finding a lot of great info!

I'm currently working on a 1000 sq ft sandstone patio area at my home. I've excavated 9" to lay down a 5" base with 1" - 2" of bedding sand and the 2" (or so) flags on top.

Base material was recommended by a material yard here in San Diego area that is basically #2 road base without the rock.

My wife wants me to leave 3" or so between stones for greenscape (she likes Elfin Thyme); I'm more inclined to make 'larger' areas (multiple pieces close together) with the 3" margin between the larger areas. That's not the question though, 'cause she usually wins... :D

My question concerns cutting the sandstone vs. rough, natural edges. Are dry set sandstone flags usually cut or left natural?

My thinking is that cutting would give a more uniform finished look, whereas rough edges would be more, well, rough looking!

Basically I'm wondering what the 'standard' installation is...

BTW, I have just about all the tools I need from circular saws to a MK101 tile saw (I'm a DIY guy to the nth degree!)

Oh, one more question: are flags (sandstone or not) typically plate vibrated after installation? I am vibrating/compacting the base course, but I'm not sure about the stones themselves.

Thanks much,

Mark in San Diego

[Lanelle]

The problem with broken stones is that they tend to be thin along the edges. These will more easily crack and crumble with usage. Some folks leave the natural shape of the stone but do some cutting to get a thicker edge and more uniform seam between pieces.

I would not recommend using compaction equipment on the stone. Damage and scratching is too likely. It's more important to get the setting bed material to fill the voids of the irregularities of the stone so that each stone is fully supported and stable. Voids make many stones susceptable to cracking.

[greg9504]

If you are cutting dry, wear a good mask. Sandstone is high in silica content, you don't want Silicosis.

I'm not a pro but personally I wouldn't go with cut edges if you are going with large gaps to plant in between. If any of the edge is exposed it will look "harsh". If you need to cut you can cut from the bottom on a 45 or so degree angle. Start the cut where you want the edge to end, then angle the saw away from that edge. So that the cut ends on the top side around an 1" or so away from where you want it. Then use a mason (concave mash) hammer (http://trowandholden.com/cgi-bin/store/agora.cgi?cart_id=8202514.440*G12DZ3&product=cat3) and trim the cut, knocking off the extra overhang left. This will give you a natural edge. You can also use that type of hammer for knocking off any thin overhangs without using the saw. Oh and if you are cutting wet with an electric saw make sure you are plugged into a GFI outlet :)

[MFortie]

Thanks for the replies!

And I'll heed the warnings about the mask and power; although all my outdoor power is GFCI protected (wife is a majority owner of an EE firm so all my power needs are 'engineered' :D )

Pricey little hammer isn't it? Good thing I've got a tool habit...

Question though: how is the hammer used -- I'm assuming you'd strike the top surface of the flag with the handle and the cutting edge parallel to the angled cut?

Never knew there were so many specialized masons hammers!

Thanks again,

Mark

[Ston Wurks]

If "IF" you do cut take a large diameter chain and beat or scrape, or just plain whack the edges-this will give you suitable "wearing". A bushing hammer is good or a needler but the chain creates a great "random" edge.

I've done 1,000's of linear feet in sandstone-my favorite patio material.