[Terre]

I really need to stick to flowers, but...

I contracted for a job, for a single woman who has bought an old fixer upper. She is sinking a chunk of money into the inside just to make it livable, but wants to invest some outside as well. I gave her a decent price on some clean up, curb appeal, and a small, dry set flagstone patio. This is one of my DIY people, which is, to maximize how far her money can go, they can do manual labor before I arrive. She was to dig out the area for the patio, down to the required depth. She figured a couple of cases of beer and 3 brothers would make a huge dent, and save her several hundred on my hourly rate.

Anyway. Six inches below the weeds was concrete. She called me, and it appears that at one point, 1940ish?, what started out as two strips of a driveway has since been filled in between, and on the sides with concrete. Then someone has hauled in a lot of topsoil/fill dirt.

Removing the concrete is way over her budget. I have the bit in my contract about underground obstructions and charging more, but she simply doesn't have the money. We will have to cancel the contract. She asked if we could simply lay the flagstone over the concrete, since I'd have been compacting the soil anyway.

I don't know, can I?

[Lanelle]

Please explain where the finished elevation will be? Just a few inches above the concrete, equal to the elevation you originally saw or even a few inches above that?
If you can put in a sufficient base and bedding layer, it should work. Also, what sort of condition is the concrete in?

[Terre]

Suprisingly, the concrete is uncracked, and looks pretty solid. Best guess, the house is of the era when driveways were two strips of concrete. So, that part I'm guessing is same era as the home, 1930s to 1940s. The concrete they filled in the middle with, is obviously different, smoother, but still in good shape.

Yes, my original intent was to have them dig out six inches or so, and the finished patio would be at or very close to the original level of the yard. It's a small patio, 10 x 12 but the concrete is up against the house. There doesn't appear to be any moisture issues. This area of town, the soil is pretty stable, I don't see the shifting or basement wall issues frequently found in the outlying areas.

[TerraSerenity]

My Friends own Sportique Scooters out there! Good Folks- Miss the day's of Tubing down Boulder Creek. Boy it sure can be cold in the spring.

Back to stone. So your Flagstone 2-3 inch thick?
Are you thinking of using Stone Dust or do you have Blue Stone dust out there? I like the Blue stone dust. In my area they have a little bit more of chips included which makes it much firmer to work with.

Sounds like you can make it work out with what you have. Not like its going to sink sitting on a pad. What are the sizes of your Flag random loose or palleted stone. How do you buy your stone out there?

[Terre]

With the spring runoff, I wouldn't go tubing in Boulder creek at the moment! But then, I'm not an adventurous sort.

Flagstone is usually 2 - 3 inches. When I do these small projects, I can select it by the piece, so I get more consistant thickness, which makes it easier for me to level, and I can select pieces that I can lift! I pay by the pound, and a patio of this size usually costs me less than $75 in stone if they go with the red.

I use what is referred to as crusher fines, which I was told is the same as stone dust. It seems to have quite a bit of the chips in it, and so far, I've not had trouble with it setting up.

[Lanelle]

This sounds like it make the job easier and faster since you'll need just a few inches of stonedust and then set in the flagstone. In our area, we would consider using a mortar bed and wet-setting the stone and grouting it .

[Terre]

The only thing I have ever done is dry set, and since I know nothing about mortar or wet-setting, I try to avoid the jobs that become learning curves. In my experience, "learning curve" is another phrase that means makes me look stupid in front of the client, and costs me money.

Besides, dry set, I can plant thyme between the stones, and still pretend I'm just a gardener. :-)

[FungusMudGrub]

I don't have an answer, but I do have another question, which is: will the concrete trap water under the flags and promote frost heaves?

[Terre]

See? That is the kind of question I don't even know to ask!

[TerraSerenity]

With a equal layer of stone dust which will hold moister but drain. I don't see it heaving like earth would. I was thinking about that same issue my self. But figured when it was all said and done-It would be fine. Mainly because its one solid area. The best part of Dry lay- its like a Bridge it can go up and down with out falling apart. Flexible systems. Yup keep it dry one less mess. A stone is a stone is a stone.

[jwholden]

It must be very frustrating for you to have an issue like this on your project, especially when you are trying to work within a budget. (Let them vent...listen, don't talk).

I have a solution for the installation of your patio without removing the concrete that will remain on budget. I cannot guarantee a patio installed on top of concrete and the contract will include this point. If you would like our normal guarantee of _ years you, or I will have to remove the concrete. How would you like me to proceed? ( Listen, answer questions, let your client drive the boat.)