Eliminating Concrete in garage floor
I’m considering how—or if—one could eliminate a concrete slab from a garage.
The uses of the space would be pretty standard garage stuff. Some seasonal wood working, lots of tool storage, and storage for a 40hp tractor and 2 ton excavator. Not cars however.
The goal in eliminating concrete would be:
1) to construct the floor cheaper
2) to reduce the embodied carbon associated with concrete
3) to have a floor that is robust ENOUGH (even if not as robust as concrete)
4) to have a floor that, if less robust than concrete, is flexible and repairable such that humps and bumps could be be repaired years down the road (and no cracks!)
Possible? Or is concrete the answer.
Most here are probably familiar with the floating wood floor system used for living spaces. I don’t see this as a good option due to oils, gases, etc.
Compacted gravel is an option I’ve considered but I would like to be able to sweep and clean up the space more than gravel would allow (and not have too much dust).
I’m thinking a compacted gravel base covered with a heavy duty rubber membrane type thing. Or other materials?
And then what for a foundation is the next question. Zone 6A, level site. Helical piles, full stem walls to frost depth, insulated shorty stems…?
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Insulation, two layer of sheathing, decoupling membrane and porcelain tiles would probably work.
Concrete is really your best option here. Concrete won't rot, doesn't care if you spill oil on it, doesn't care if it's wet, is strong, is flat, is easy to get, etc. It's really the best option here.
The big problems with a membrane is that any big point loads -- like a heavy tool with four small leveling feet -- will have a tendency to punch through the membrane. You'll never get a flat floor with gravel, either, regardless of how carefully you compact it. Point loads will damage most earthen floors regardless of how you compact them. A subfloor and tile system could potentially work, but would not have the longevity of concrete, and would be more complex to build.
I would NOT go with a wood foundation, either. Helical piles can be intersting, but would need to be engineered. Concrete has the advantage of being well understood, which makes contracting out the work much easier. Remember also that if your foundation fails, the rest of your structure probably will too, and foundation repairs are VERY EXPENSIVE.
Sometimes ye olde building materials are still the best options, and in the cases of things like foundation walls and slabs, I really think concrete is the best option. If your goal is a green build, be careful with your materials selections for things other than the foundation. There just aren't a lot of options out there that can beat concrete for durability or ease of construction.
Bill
Tyler,
You may find this earlier discussion useful: https://www.greenbuildingadvisor.com/question/concrete-free-slab-in-a-garage.
There was more thorough look at it in another recent discussion but I can't find it.
Thanks. Yeah I thought it had been discussed here but couldn't find it.
I agree that the wood systems are out. I still think perhaps a rubber covered gravel could work, but it's true that heavy point loads or other rugged loads like twisting excavator tracks would wear on it much more than concrete.
If going rubber (which in all likelihood I probably won't for the good points above) I was sort of picturing something along the lines of these heavy mats
https://www.ekomats.com/
placed over some heavy poly or something, with a screed layer of stone dust, pea stone, or sand to flatten out above the compacted gravel.
These mats have been used as universal access trail surfacing in high-wear areas. Obviously there would be joints and so the barrier beneath would be necessary. Probably not nicer than concrete. Maybe cheaper.
You may not need poly if you use mats like that. The primary issue I would see with those mats would be that you won't have a particularly even floor surface. You would likely also have some issues with point loads as I mentioned previously, although if the mat is heavy/thick enough, it will only deform rather than puncture.
Bill
Tyler,
If the mats aren't too expensive it might be worth trying. You can always pour a slab later if they didn't turn out.