My uncle had a basic shop built on my mom's land a few years ago, to house his antique cars. When he passed, my aunt sold the vehicles, and I got the building.

It's a basic 30x40 metal construction, with the structure being posts set into the ground, and a dirt floor.

I had the idea of putting some footings and joists in to make a better floor, and then building a sort of apartment inside, while leaving most of the building open.

My question is, would putting such a floor in be a good or bad idea?

I have the skills to do it myself, but I'm unsure of the pros and cons.

Thank you!

Why not concrete? Perhaps even with a heated floor/skim layer? In our climate, that'd be the norm. Perhaps crawlspace is more normal in your climate?

Off the top of my head, I see three possible issues:

1. Moisture wicking up from the dirt floor and causing issues with lumber construction of the new floor and/or insulation. Solution: Moisture barrier over the dirt.

2. Building moving in relation to the floor with temperature changes. Might not be an issue if you don't get really cold weather. Not sure if tying the floor to the building frame would be a good or a bad thing.

3. Access for plumbing/electrical/HVAC. If you can raise the floor enough for a crawl space and still have adequate headroom, shouldn't be a problem.

Probably a good idea to check local codes and permitting before driving any nails. A lot of places are regulating "barndominiums", seeing them as an attempt to avoid taxation.

When you say the posts are in the ground are the posts metal or wood. That is is the building a true metal building or a pole barn type?

I'm with the majority here in that it would be better to pour a slab if possible but I would first use a skid steer and excavate 4 to 8 inches of the dirt out. Then put 4 inches or so if 3/4" gravel followed by a 10 mil plastic vapor barrier and 4" of fiber reinforced concrete professionally finished.

You will need to run any underground plumbing and possibly electrical before pouring the slab but this will give you a great floor to build your abode on.

+1 for a heated floor.
My mom has it in her Denver house.
-15 outside & we didn't even run the furnace, and no cold feet.

When I was a kid, my Dad built a large shed / small barn and it had a gravel floor. Mower decks and other equipment that trapped moisture wicking up through gravel caused high corrosion rate. After losing a couple mower decks (tractor and push) to rust, he ended up parking them on plywood. He told me he regretted not having a concrete floor.

He's moved and his current shed is much smaller so it has a wood floor w/ a ramp to drive his tractor into the shed. Zero rust issues

quote:

30x40 metal construction, with the structure being posts set into the ground

Does this mean metal skinned building w/ metal structural posts/framing or does it mean metal skinned building with wood structural posts/framing?

If it's the latter, it's worth digging about a foot deep around a few wood posts to see if they're rotten. Definitely do this before you spend any money on a new floor. Much cheaper to fix structural issues now while the floor is dirt than it is after you've spent money on concrete.

It is wood frame, with metal on the outside.

Check out Garage Journal .com. There is a ton of info there.

more info on what you are thinking in terms of an apt. A dry apt. No water? Heat source? Are you planning to live in it or have some one live in it. Or use bonnie and clyde style or what.

But yes you could do it. Screw the permit bs if you plan do just use occasionally yourself. Do it as you see fit if you can.

I have a 30x40 pole barn with an 8' porch on the 40' side (38' trusses).
I have concrete with radiant heating & it is very cheap to heat, but the up-front cost of the combi boiler system can't be described as 'cheap' in any way. I keep it at 55* in winter & I get hot in jeans & a sweatshirt if I'm working on something that takes effort.
Depending on your planned use, you might want to look at codes & insurance for a 'pole barn' house/apartment. It might be difficult to get permits/insurance for that type of structure. My 1 regret in the construction is that we set posts rather than pouring a footing & using post brackets - that's the difference between pole barn & 'permanent structure' in most cases.

Also, a wood floor inside a pole barn sounds more like 'cabin' to me than an apartment. You'll probably need piers inside the post structure.

You may have difficulty keeping rodents out of the pole barn/apartment. Most of the barndominiums around here are lousy with mice.

Thanks for the replies, everyone. It's looking like it will be more sensible to just put a small cabin next door. I'm tired of living in a camper, and want a bit of a step up.

quote:

Originally posted by Plugugly:
Thanks for the replies, everyone. It's looking like it will be more sensible to just put a small cabin next door. I'm tired of living in a camper, and want a bit of a step up.

If you are going to live full time in it sounds like a good idea.

I built a really nice pole building shop with a concrete floor several years ago. Fully insulated walls, ceiling, etc. wired, sheetrocked and paneled. Has three 12x12 insulated doors. Has a wood stove. We have real winters. I could easily live in it and be totally comfortable though. No rodent issues either. Just say'in.

Good luck.

I agree your 1st stop is to talk to local code enforcement and see what is permitted.

Only after that will construction details matter, my 1st thought would be a slab vs building up a crawlspace.

I love the barndaminium idea though, my version would be with a hangar on an airstrip!

pour a slab. I've done it twice now and the difference to a dirt floor is truly dramatic. Add heat if you want but just pour the floor.