We have ripped our our flagstone patio/pathway and are redoing it and building to direct pathways to the lawn. Previously we used sand as a base and mortar to hold the flagstone, which was a mistake as overtime they settled and cracked around the edges. We've cleaned up the flagstone and now will be building new paths. We live in Colorado (south of Denver) and the soil is clay-like. What should we put down first? Sand or gravel? I also wanted to fill this in with breeze this time but is this okay or are there other/better suggestions. Thanks!

I just built a quartzite patio in Reno, NV. I used the new product, polymeric sand and it worked great! I got the sand in 60 lb bags for $20 a bag from Home Depot. My patio is 9X27.5 and I used 5 bags. It looks like regular sand and sweeps into the joints. You then mist it 3-4 times waiting about 10 minutes between each misting. The water activates a weak polymer glue and locks the sand granules in place. We don't have much problems with frost heaves here, but if a stone moves you can pull up the sand in chunks and step on it or use a shovel to get it back to a granular stage, sweep it back in place and re-mist. Although the polymeric sand sets up pretty hard I don't think it would stand up to a leg from a patio chair, etc., so we plan on getting sled style chairs for the patio. It does do well with walking on it and the sand stays put! So far we are very happy with it. I'll let you know how it goes thru the winter. We get very little rain here but we do get snow.

Hi, I just wanted to let those interested know what tips I have learned in designing/building stone block edging around my entire house with an integral flagstone patio. I didn't want colored concrete blocks or rubber edging. I decided on Minnesota Kasota (limestone) natural stone (sized) blocks & 2" flagstone sheets. I contacted a quarry and showed him my design I made on graph paper. He walked around and measured the square footage required to make an entire 8" (two 4" blocks high) curved garden wall above ground, 4-5 feet from my house (except in back of house for the wrap around above grade flagstone patio) that I will backfill with blackdirt, weed barrier, and 3 " of decorative stone or mulch on top. Getting back to the purchase of my stone, I went direct through the quarry and avoided the middle man. I was able to get wholesale price with discount and reduced shipping charge. The order was for 19 tons of tumbled stone retaining blocks (sized 4" thick x 8" wide X radom lengths)and 2" flagstone. I needed about 6000 linear feet of block. I started out by buying 1.5" pvc pipe with couplers to make nice uniform curves/semicircles around my house held by stakes, then spray painted lines around for the block following the natural grade of my yard. (This method worked much better than garden hose). I rented a trencher with a 4" block blade and followed the line around three times so I had a nice trench 12" wide X 4" deep. I shoveled out the dirt and cut landscape fabric in the base. I then put in compactable gravel that I hand tamped 1" below the sod. I then started setting blocks in the trench and found just the right lengths/ slightly angled pieces I needed in the pallets of stone blocks. I then started on the second layer overlapping the joints by 5" inches or so. After the second layer was on, I removed the top layer and placed them on the ground facing up. I then brushed /swept the surfaces then applied block glue to each one and put them back. One area by my garage needed to go up 5 feet of block, so I just kept stacking/gluing blocks except I moved in each row 3/4" above previous row. Now for the raised flagstone patio. Now that I had a nice curved block wall 8" high, I filled/raked 4" high compactable gravel inside, rented a compacter and went over it 4 times. I strung lines across the top of the 8" high block and measured down the thickness of the flagstone (2"-3/8" for sand compaction) and layed long lengths of old 1.5" waterpipes on top the gravel surface and shimmed the pipe up with wood up to where the bottom surface of the flagstone should be. I then shoveled in course washed sand on top of the gravel/pipes and using a long 2x4 resting on top of the pipes to screed the sand flat. Now I started laying flagstone. The flagstone was in big square sheets, so I tipped them onto the ground, and if they didn't break, I took a splitting axe and hit in the middle several times until it broke into smaller pieces that were still at least 2-3 feet in size. Take on piece at a time and lay it onto the sand, then take each matching piece and lay adjacent leaving a 1.5" gap for motar or sand. Continue this process like a jigsaw puzzle. When you have to cut or trim, I used my kid's sidewalk chalk to mark lines/cuts. Then use a stone chisel / hand sledge hammer to chisel along line two times to score a line. I then rap one end of the stone with the butt of the sledge and it breaks clean along the line. If needed, chisel away any ragged edges. Work from one edge outwords using large pieces, then going back and filling in any smaller pieces. As you go along, try to keep edges of flagstone nearly flush. If you disturb the sand as you going along, use a cement trowel to smooth out. When your all done fitting, you can fill joints in one of two ways; buy SANDLOC and mix with sand and water, then put into joints, or what I am doing is mix 1/3 cement with sand and put in joints, smooth and wash away rest from flagstone using sponge. These are the only two things I would do for patios to make sure ants don't start drilling or plants/weeds don't start. Good Luck, Hope this helps.

Xiaohan, Are you saying that the gravel is individually 2 to 3" in diameter? That's very coarse gravel to work in around flagstone...or is there an existing gravel bed into which you want to lay the flagstone? Whatever the case, if your flagstone is only 1" thick, it doesn't really make sense to use such large gravel. I don't think you would want the gravel to exceed the 1" thickness of the flagstone.