Concrete/Hardscape info needed

[MB1008]

Well, I finally decided to chip up all the cracked mortar between the flagstones on my patio. The patio is about 8' by 13'. After getting the majority of it up, it appears as though whoever installed it basically put it on soil and filled the joints with mortar. From what I'm reading online, the mortar will crack 100% of the time if you just set it in soil and if I'm going to remortar, I want to make sure I'm not going to have to do it again in a couple years.

Having said that, the mortar didn't start cracking until this year (my house is 14 years old and I've been in it for 3 years. The patio is probably 5-7 years old.

So my questions are....

Does anyone know if it will be okay to just refill the joints with new mortar? The stones are 2"-3" thick. Would it work if I dig down 3"-4" in the soil?

Or should I have a slab poored and install the stone on top of that (this is the strongest of the methods that I've read about online).

Though if I had a slab poored, I might not even worry about laying the stone over it. Maybe just have the concrete stamped.

Also, does anyone know any concrete contractors and/or rough estimates of how much an 8' x 13' slab would cost?


Thanks

 

[doctorjj]

It needs a slab under it. Standard concrete patio should run you about $5 per square foot. Anyone charging less, I would question their abilities. Stamped is gonna be higher. If you're up to redoing the mortar then you should be able to pour a slab and do the flagstone right. It's not that much extra work. The slab doesn't have to be perfect or pretty at all if you're just going to cover it with the flagstone.

 

[MB1008]

How thick of a pad would I need to pour and would I need to use rebar or something like that? How do I make sure the slab "slants" away from the house?


Thanks

 

[twoguns?]

How wide are the gaps between the stones? How big are they? If they are large stones they should be "set" in the ground>
Put fine sand in between them, then spread mortar mix with a broom untill all the stones are clean .
Water gently, it will harden, but still be flexible from the sand.
This summer heat with noooo rain mkes a lot of things ...Move

 

[doctorjj]

I'd go with a 4" thick slab with rebar going both ways on 24" centers and rebar around the edges. As for the slope, set up the form at your house at the elevation you want, then use a string level an shoot for a minimum of 1" fall per 10 feet. I like about 1 1/2" per 10 feet on something like that.

 

[soonersfan]

Just put pea gravel between the stones. It works fine in that application and will actually look better than concrete.

 

[Shoot Summ]

It's standard to set thicker stone on a sand base. Not typical to just set it on soil though.

 

[MB1008]

Well I just lifted some of the stones up and there is some type of small pebbles under the flagstones. The stones don't feel like they're going anywhere. They feel solid when I stand on them (no rocking or anything). Pea gravel is a good idea but I can't stand the idea of gravel sticking to my shoes and being dragged in the house so I won't be going that route.

The stones are set 1" - 1.5" apart and they are roughly 1.5-4 square feet in size. I like to think mortar in the joints will work but I hate to be back in the same place 1-2 years from now. Though I also hate for a $100 project to turn into a $500-$700 project.