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Filling hole in carport (concrete slab)

11K views 2 replies 2 participants last post by  chaddihimself 
#1 ·
I recently removed a small flower bed that was surrounded on 3 sides by the carport slab and on one side by the house slab. My question is what process should I follow to fill this area with concrete. Most notably, I am getting conflicting info from the internet - some places say to use an expansion material next to the house, and some say to use / not use a bonding material.

Do I use an expansion material because I don't want a space to show between house slab and this slab because there is no space between the carport slab and the house slab?

Do I use bonding material? If so, only to the carport slab or to the house slab also?

Should I use reinforceing mesh even if it's only a 1 foot by 6 foot by 4 inches thick slab, or can I use fiber concrete products?


Thanks for any help!
 
#2 ·
I recently removed a small flower bed that was surrounded on 3 sides by the carport slab and on one side by the house slab. My question is what process should I follow to fill this area with concrete. Most notably, I am getting conflicting info from the internet - some places say to use an expansion material next to the house, and some say to use / not use a bonding material.

Do I use an expansion material because I don't want a space to show between house slab and this slab because there is no space between the carport slab and the house slab?

Do I use bonding material? If so, only to the carport slab or to the house slab also?

Should I use reinforceing mesh even if it's only a 1 foot by 6 foot by 4 inches thick slab, or can I use fiber concrete products?


Thanks for any help!
This is strictly my opinion and what I would do if it were my house.

I would excavate no less than 6" from the top of the slab. I would tamp the earth then put in a couple of inches of wash stone or 2" stone in the hole. I'd level and tamp that a bit then put 2 runs of #4 rebar down the length of the form and suspend it with some of those little rebar chairs. Then I'd pour my concrete.

Why not use expansion material? Exactly for the reason that you stated.

Why not use bonding material? I don't see any compelling reason to do so unless you feel the new slab is going to sink below the driveway.

Why not use re-mesh? Because the dimensions of the form means you'd have to custom cut it and wrestle it into place and quite frankly its not worth the ass whipping that it'll put on you. You can have rebar in the hole in 2 minutes.

Why not use a fiber additive. My experience with using fiber in a "hand mix" situation has not come with good results. If you have a mechanical mixer and can get the fiber thoroughly incorporated into the concrete, without it clumping up, then you may have better results. I'm assuming you're going to hand mix since it's only 2 cu ft of concrete.

Other's may have differing opinions and truth be known all our advice will probably conflict with what you've read elsewhere.
 
#3 ·
Thanks

Thanks for the direction. This is far and away better advice than I've encountered. I will go with this technique because I don't anticipate any settlling in this area. The most common form of settling here in Florida is sinkholes and I just hope I don't have that!

Thanks again.
 
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