[oxfletch]

I am looking at transforming an old barn into a house. In the "lower floor" the concrete floor is strong, but quite varied in height. Most places it's close to 8ft, but there are various troughs etc cut into it for sluice, feed etc.

Initial use would be garage/basement, but I want to leave the possibility of converting it into finished livable space later.

There's a ramp down one side I think we'll have to jack out, hopefully without disturbing the foundation. Most of the rest of the variation is only up to 6" or so deep. Typical areas might be 2" deep and several feet wide strips or 6" deep and 8" across.

Any advice on the best way to deal with leveling the rest of the area? I am trying to control (a) cost and (b) how much height we "use up".

The ideas that strike me initially are
(1) pour concrete enough to level it, then float a vapor barrier and plywood subfloor on top. That seems cheapest and easiest, but presumably not strong enough for a garage floor, and I'm worried that small sections of concrete won't be very stable?
(2) float it level with compacted fill, then pour a 4" reinforced slab over the whole thing (or at least the garage part). I'd lose 4", and it'd cost a bit more, but maybe a good compromise. Do I even need 4" depth if there's a strong base underneath?
(3) Try something like 2x6's across as joists, supported to the (variable height) floor every few feet by "stub joists", then put plywood subfloor over it. Loses more height. Cheaper? Might give good space to allow underfloor heating, electrical etc, at least in the non-garage part.

It would all get permits and approval before anything happens, but I'm trying to get a rough idea what I'm dealing with. Any advice much appreciated.

 

[oh'mike]

How much height do you have? Could you cut out any curbs and simply fill the low areas> If you want a good looking floor---you will need a continuous pour---to do this you need to remove the old concrete--or add 3 or 4 inches on top of the existing.

Forget the idea of overlaying the concrete with plywood---the moisture from the concrete almost always causes early failure ----

 

[oxfletch]

Apart from a 3.5 ft wide ramp (16" high) all along one side, I think it's pretty close to 8ft high all across.

So if we jack out just those ramps, I can certainly fill the rest of it and float a new slab over the top ... just pouring a 4" slab seems like it's going to eat a large chunk of the budget (it's 3500 sqft). Estimates online for the installation costs alone seem to go up to $10/sqft. Maybe it gets cheaper per sqft for larger jobs?

Yes, the plywood does seem like a hack job. I was hoping a pressure treated joists, then moisture barrier then plywood would fix that, but maybe not.

 

[oh'mike]

You will loose to much height----a framed floor--even 2x4s with ply on top will take up a lot of height---

Do you know if the floor remains dry during wet weather?

 

[oxfletch]

Seems like 2x4's + ply would take up about the same as a 4" slab ;-)
The slab seems like the "correct way" to go though I guess.

It actually looks dry, despite some farmers piling up 3' of soil around the concrete walls on two sides (I suspect with no french drain). I plan on removing that if I can. But then again, it might not look so dry in spring.

 

[oh'mike]

Sounds like an interesting project----

A few things that might help----a small Bob Cat skid steer loader could be driven right in and used to break up the ramp and any floor that needs removing---there are jack hammer attachments for those machines---

Hydronic ,in floor heat , might be in order---this is an inexpensive way to heat a building like that and does not have the bulky duct work that forced air requires.

Anti-freeze can be added to the system if some areas might be left unheated except for special occasions.

 

[joecaption]

Going to need at least 7' of head room to make a code approved room.
And that's after finshed floor and ceilings go in.

 

[oxfletch]

Skid steer based jackhammer will definitely help ;-)
Whilst searching on google, I found a picture that's similar: http://cdn.backyardchickens.com/d/da/da34cbd9_DSCN5852.jpeg
Far side is the "elevated ramp".

joecaption: I think I can make 7' fairly easily - just would prefer to keep it closer to 8 if I can.

 

[oh'mike]

I had a customer look seriously at an old dairy barn---they wanted to turn it into an art studio---so I am familiar with the structure and the floors---with all of the built in feed troughs and drains---

That's why I thought of the skid steer with the jack hammer---Might be worth looking for a used one for the project and reselling it when done----they are a useful tool on a project like yours--

 

[Msradell]

Why don't you just take out the ramp in other protrusions and fill the protrusion with dirt? That's sufficient for a garage. This will give you time to see if you have a water problem and avoid major expenditures at this point. Later you can determine the best course of action based on needs and available resources.