Concrete over Concrete

[LT4]

I am considering adding a bay to my garage. I have an existing heavily reinforced agregate concrete parking pad where I would like to add the bay. I want a smooth floor and would like to increase the height of the existing pad to prevent water run off from entering the new bay. Is it acceptable to dig a footer around the back and side and pour on top of the existing parking pad?

 

[Matti]

I'm no expert on this but I did talk with a concrete guy about this a few weeks back. If the concrete is reasonable you probably could but would have to 4" thick which usually nixes this plan.

 

[JCByrd24]

Yes it should work just fine. You may also want footer supporting the front wall depending on if it is supporting roof load (assuming there is at least some portions of wall in the front not taken up by overhead door openings. I don't understand why Matti's concrete guy is indicating a 4" pour minimum though and don't feel it would be necessary in all situations.

 

[LT4]

Thanks for the responses. When we moved last fall I gave up a ton of floor space in my garage. Now I am trying to figure out if I can gain some back. I don't have to worry about winter or the locals as we're out of the city limits. My only worries are expanding the hip roof and recovering the parking pad.

 

[e-tek]

Thanks for the responses. When we moved last fall I gave up a ton of floor space in my garage. Now I am trying to figure out if I can gain some back. I don't have to worry about winter or the locals as we're out of the city limits. My only worries are expanding the hip roof and recovering the parking pad.

PICS PLEASE!!!!

 

[Matti]

How much do you want to raise it? Perhaps you could go with a better grade of concrete and go thinner. I would talk to a concrete company.

 

[boiler7904]

See if your local concrete guys will use a "topping mix" which uses pea gravel as the coarse aggregate instead of 3/4" stone. It's used all of the time for concrete slabs on metal decking in commercial construction. As long as it's at least 2 1/2" or so thick, I don't see why it wouldn't work. You'd want use a bonding agent between the two slabs. Cut your new control joints directly above the existing joints that stresses aren't being transferred through the floor.