Stone floors, any suggestions

[texican]

I've tried to find a forum or a site that might answer my 'engineering' question, to no avail, so I figured I might check out the brains here.

I've got several dozen boulders, some good for nothing but landscaping, but quite a few huge (~6' x 8') flat boulders that I want to incorporate in a portion of the floor in my new home. Basically huge flagstones. I know how to lay flagstone, but these are around 6 to 8" thick.

A straight slab won't work, as they'd stand up very high, and the baby flagstones would have to have a six to seven inch bed of mud to level the floor out, so that's unreasonable.

Easiest solution would place the boulders in place, blocked off the ground, with all the vapor barrier and steel in place ready for the concrete truck. My only concern is getting the concrete completely worked under the rock, and keeping the rock in the right 'attitude'. Shifting during the pour or cure would mean a huge chunk of trouble.

Another solution is to map out the boulders position in the slab. Make indented slots for the boulders (widths x depth +wiggle room). Finish and cure the slab. Then set the boulders into their matched holes, mortar and grout, combined with the other flagstones, or slate, and be done with it. Concern with this process is moving the boulders over the cured slab. Would hate to crack the slab. Neighbor has a huge crane that is available, that'd easily move the rocks (and beams later), but he's going to sell the crane, more than likely before this project begins.

The rock is free. Currently within 20' of where I'll need it, either in floors or walls or landscaping. I saved them from getting covered by 30' of water when my pond was dug. My dozerman's eyes got big one morning when he showed up for work...a handful (bad pun?) of the boulders were parked up on the hill next to his dozer...he looked at em and wondered how they got up there...Noticed after that day he'd push the larger VW sized ones out...and I'd get all the minor yugo sized ones out after he was gone...and after I'd put in three or four hours digging with his D6.


Any critiques, advice, websites, etc. would be appreciated.

I know stone is cold. I hope it IS cold in the summer. In the winter, free natural gas tends to neutralize the coldness.

BTW, I know I don't '''need''' rocks that large. This home is not about needs. I've got my '''needs''' home already. This is my 'wants' home. I was hoping to make it onto HGTV's Extreme Homes, but alas, it appears the series is in hiatus, or has been cancelled.

[DrippingSprings]

This is what I did and maybe it will work for you.

In my den I wanted a real rustic look. Everything is based on a mtnman type theme. Muzzleloader over stone fireplace. I even went so far as to cut down trees and have them split in two to line the walls to give a cabin look to it.

I was puttin thoughts on flooring through my head and for whatever reason rock to match the fireplace just kep coming in to the picture. Considering my fireplace took up one whole wall and it was rock I dint want over kill with rock as the rest of the floor I wanted to be very warm pine.

I went out and found two very large flat stones. When I say flat I am talking slabs and not round boulders. I had a triple door coming into the room from outside. I took the slabrock that was between 4-9 inches thick down to a local shop. I had them cut the rocks or actually I should say slice the rock. The largest was almost four ft across. That being at the longest width. So by slicing the rock I ended up with four pieces. Reasonably close to the same thickness and of the four they wer basically two similar patterns. I put them in front of the doors and it worked out great. I inserted them rough side up and staggered them and everyone always compliments them. So i ended up with four beautiful stones from two beautiful stones and they were fairly unfirom size wise. Those covered right at a 6x12ft area inside the door with minimum spacing between them.

If you wish to cover a whole floor I would take any rocks considerably thicker than the average ones and just slice them and you get close enough to solve your bedding problems and still get an ''extra rock'' off the other side for free.

[westbrook]

ever tried splitting the flag stone?

I have flagstone everywhere. what I don't like about it is its unevenness for placing chairs and tables. Even the hearth of my fireplace is flagstone. It is very flat and nice, but just setting a glass on it is wabbly.

I bet it will be beautiful in your kitchen!

[insanity]

Why couldn't you just mix up a few bags of Quick Crete,pore it out,place the stones,and then have the rest of the concrete delivered by truck.After the bagged crete has set up? Might call and ask concrete company about it bonding to gather?But id think if it was left rough around the edges it would be fine.

Could use bricks/rocks or anything to prop them up level until the concrete drys,couldn't you?

Humm also wonder how tamped wet sand would work as a base then pore in the concrete from the truck.I wouldn't think a stone that big could/would move.

[agmantoo]

Why not just step the slab to where the "flagstone" area is 8 to 10 inches below the balance of the floor? Then when you install the flagstone it will come to the same level as the rest of the flooring. A concrete vibrator will allow the motar to fill in beneath the stones. Use 3 legged furniture in the flagstone area and you will not have any problems with everything teetering!

[texican]

thanks for the suggestions...

I've contemplated splitting the stones, some definite bedding layers. This is a sandstone with calcareous inclusions, the more limey the better (harder).

Hadn't thought of splitting for mirror images...

Thought about the quickcrete fix (what I did in my current home, on a small addition, that included a boulder base)... I just get nervous around huge pours, and a professional crew is more than the projected cost of the home. (I do everything but slabs )

I didn't even think about vibrators (raised in the Bible Belt, if you mentioned vibrators, you'd best have a good reason, and in the right context.. :haha: ) The vibrator would definitely get the concrete under the rocks in all the right spots.

I play devils advocate with myself so much, trying to chess match plan out all possibilities, and find preemptive solutions. Your ideas have put a few more of the puzzles in place.

These will be going into a 12x30 entry hall, so if there's some unevenness, no problem. I'm going to try and do a weblog of the construction, if I can figure out Google Blog, or maybe the Geocities route.