Sloping a flat slab


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Old 02-03-22, 04:29 AM
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Sloping a flat slab

I had a 20'x40' slab poured for a shop. It was done in stages as money was available and being new to the game I just had it poured flat not thinking about the overhead doors. Now the shop is up with two garage doors that are inset. Is it possible to slop where the doors are now to stop rain pooling up and seeping under the doors.
 
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Old 02-03-22, 04:50 AM
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You can cut or grind a slope into the concrete.
 
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Old 02-03-22, 05:00 AM
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They also sell rubber strips that can be glued down under the door to stop water from flowing but I'm not sure that is fool proof and maybe creates another issue of something in the way.
 
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Old 02-03-22, 07:21 AM
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Pilot Dan, I thought about doing that but since I know NOTHING about working with concrete. I wasn't sure if the water would absorb into the concrete where the new slop was. (if that makes sense)
 
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Old 02-03-22, 09:25 AM
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Water will absorb into concrete cut or not. And as a material concrete really doesn't have a skin. It's pretty much the same all the way through. But, water/moisture is wicking up through your slab right now. When pouring a slab for a house it's common to put a sheet of thick plastic sheeting down first to help slow the flow of moisture up into the concrete. It's also why you never build with untreated wood on concrete. The bottom plate is always pressure treated.
 
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Old 02-03-22, 10:09 AM
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Around here they always put a lip where the garage door is. That 'lip' is about a 1/2" lower than the slab and a little wider than the door's thickness .... but it's a little late for that now. I think grinding a slope will help, maybe eliminate the water intrusion. It's also common to lay gravel down under the slab to facilitate drainage.

If rain runs off the roof in front of the garage adding gutters might nhelp.
 
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Old 02-03-22, 01:56 PM
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Well cutting and grinding concrete is easy. How much are you taking off? an inch or two?
 
 

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