foundation walls vs slab only

[CentralIL]

I am building a garage in Central Illinois. 34’x54’x16’, 2x6 walls, scissors truss
I am raising the grade of the garage floor about 18 inches. Because of this, my contractor has recommended that I put in foundation walls. The concrete only bid for this is $9,800.

The other option that I was given was to expand the amount of fill and create about a 44’ x 64’ rock base and then just pour the 34’x54’ slab on top of that. The concrete bid for this is $5200. In other words, I would save $4,600 in concrete by not putting in the foundation walls. Although, I would have to add more fill and my excavating costs would increase.

This building is pretty much right next to my house. I will be landscaping around it and I would like it to look as good as possible when complete.

My question is…are the foundation walls worth the extra expense? Or…do I have other options?

 

[1320stang]

Uhhh....

....Yeah, you're gonna need a foundation. Unless a cracked and heaved floor is the look you're going for. Think about how much weight is going to be on the edge of your slab. 2x6 walls of unspecified height and a 34'x54' roof? Scissor truss, are you putting in a lift?

 

[kbs2244]

For 1320’s reasons, I would go with the walls.
You might look into having poured footing, and then concrete block up to grade instead of poured walls.
You might save some that way.

 

[CentralIL]

No lift. This is just more of a bonus room for my two boys and I. We are avid basketball players and will be using the garage to shoot around in during the winter months. The garage will also be used for storage. Boat, lawn mowers, 4-wheelers, tools...etc.

So…your recommending against any design that does not include foundation walls due to the weight of the building?

thanks for the response.

 

[Junkman]

Don't know your building codes, but around here, you MUST put in a footing, and a foundation wall for any building except a pole barn. Floating floors are just plain problems in cold climates. They tend to heave and move about during the winter month freeze and thaw cycle. I have one garage that was built on a floating floor, and the floor itself hasn't cracked, but it does move enough during the winter that the doors stick when opening, if you adjust the doors to open smoothly in the winter, then they stick during the summer. Also, perimeter rot is another big problem when there is no concrete wall for a foot or so above grade. The water splashing on the walls will cause you problems. Do it right the first time, or you will forever live with problems. Saving $5000 over the lifetime of the building is false economy. Some people say that they are not going to be living there for that long. Someone else is, and they will pay less for a poorly built building than one that was well built.

 

[JMURiz]

For 1320’s reasons, I would go with the walls.
You might look into having poured footing, and then concrete block up to grade instead of poured walls.
You might save some that way.

That's what I had done on mine, thought it was normal practice to do it that way.

Having said that my house has a 8" thick poured foundation (no block) and cured for 65 years and is solid as can be...concete was a little less $ back then too.

CentralIL: You must be the best dad ever, indoor basketball court...sweet!

 

[CentralIL]

For 1320’s reasons, I would go with the walls.
You might look into having poured footing, and then concrete block up to grade instead of poured walls.
You might save some that way.

I am going to look into this option.

What, if any, are the disadvantages of going with a concrete block wall instead of a poured wall?

 

[kbs2244]

Some guys do not like them for basements. They are afraid of side loads.
Not a problem when you back fill. Then the wall is supported on both sides.