Garage Question

[boonrak3r]

Hello, First Post:

I'm building a garage for a corvette in Ontario. I understand that the foundation has two options: 1. monolithic concrete slab 2. stem wall foundation.

If I understand correctly, stem wall foundation is the superior choice given its more resistant to cracking/settling and keeps things dryer; however, it's also much more expensive than slab. I'm wondering whether slab is sufficient or whether I should just pay the extra money for stem wall.

Any experience or opinions on this? Thanks!

 

[Murray20c8]

Hello, First Post:

I'm building a garage for a corvette in Ontario. I understand that the foundation has two options: 1. monolithic concrete slab 2. stem wall foundation.

If I understand correctly, stem wall foundation is the superior choice given its more resistant to cracking/settling and keeps things dryer; however, it's also much more expensive than slab. I'm wondering whether slab is sufficient or whether I should just pay the extra money for stem wall.

Any experience or opinions on this? Thanks!

Welcome to the forum.
It might help if we knew where you are. I can't help, but I'm sure average mean temperature would have something to do with it.

 

[DW Ruby]

Hello, First Post:

I'm building a garage for a corvette in Ontario. I understand that the foundation has two options: 1. monolithic concrete slab 2. stem wall foundation.

If I understand correctly, stem wall foundation is the superior choice given its more resistant to cracking/settling and keeps things dryer; however, it's also much more expensive than slab. I'm wondering whether slab is sufficient or whether I should just pay the extra money for stem wall.

Any experience or opinions on this? Thanks!

Pay the extra money.
Better yet, hire yourself an Engineer (you will need one for the permits).
While you could build a garage on top of a simple slab-on-grade from a Structural point of view, the frost would play havoc with it in very short time.
Typically in Ontario, the underside of the strip footing needs to be 4 ft below grade.
Good luck.

 

[Rruuff Day]

Hello, First Post:

I'm building a garage for a corvette in Ontario. I understand that the foundation has two options: 1. monolithic concrete slab 2. stem wall foundation.

If I understand correctly, stem wall foundation is the superior choice given its more resistant to cracking/settling and keeps things dryer; however, it's also much more expensive than slab. I'm wondering whether slab is sufficient or whether I should just pay the extra money for stem wall.

Any experience or opinions on this? Thanks!

Will your garage be heated 24/7? I poured a 6 inch slab on grade over 12 inches of well compacted gravel. The concrete has 2 layers of 10M rebar on 12 inch centers. That was 17 years ago and it hasn't cracked anywhere yet. My garage has been heated 24/7 since day 1. A well compacted base and the rebar is key for a good product. Heated keeps the ground from freezing below. I am a retired engineer so had access to a big compaction roller and supervised my contractor. Not trying to talk you out of a stem wall. Just letting you know what I did.

 

[Murray20c8]

I have no idea how they built my unheated barn, but the slab has no cracks in 40 years. I'm sure, like Ruff says, a well built base is the key

 

[Rruuff Day]

I have no idea how they built my unheated barn, but the slab has no cracks in 40 years. I'm sure, like Ruff says, a well built base is the key

Chopped fiberglass strands in concrete is available as well. Have never used it in a project but supposedly has great crack resistance.

 

[Ben Malik]

Will your garage be heated 24/7? I poured a 6 inch slab on grade over 12 inches of well compacted gravel. The concrete has 2 layers of 10M rebar on 12 inch centers. That was 17 years ago and it hasn't cracked anywhere yet. My garage has been heated 24/7 since day 1. A well compacted base and the rebar is key for a good product. Heated keeps the ground from freezing below. I am a retired engineer so had access to a big compaction roller and supervised my contractor. Not trying to talk you out of a stem wall. Just letting you know what I did.

I have a standard slab on grade, 5 inch thick by my home builder. After 5 years, a couple of cracks did appear. I then went and spent some good money on getting the two cracks repaired and then topped it with solid epoxy work. Not epoxy paint (that’s useless), full epoxy work and had my garage re-drywalled/insulated and added a heater.

No issues since. I keep my garage at 10 to 11 degrees C during the winter months along with over inflating the tires. No issues what’s so ever.

 

[Tindale]

One shop 24 x44 poured 6 inches thick with wire mesh in 1980. The other shop 40 x88 poured around 1997 , 4 to 5 inches thick with fibreglass reinforced concrete , packed gravel bases , never heated and never cracked. The small shop was straight slab no relief cuts , the bigger shop we cut some relief cuts into it , not exactly sure but probably around 20’x 20’ squares. A slab is not rocket science especially if it is just a garage. We are north of Toronto in Midland so it does get cold but I am also on top of two hundred feet of sand so it would never heave in a million years from frost. That being said if you are on clay you may need to get footings below the frost line .