replacing a concrete stairway


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Old 09-17-15, 06:28 PM
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replacing a concrete stairway

Hi,

I have a concrete/brick stairway that goes to the front door of our house.

The concrete/brick stairway, which goes up ~5ft, and landing needs to be replaced. Currently, the stairway is hollow underneath, and is supported in part by rebar.

A contractor proposed to fill the area up with base rock, and then pour a 6" concrete slab over it, install rebar ever 18" on center, and then lay brick over it.

The result is that the stairway will no longer be hollow underneath, and instead will be completely filled with base rock.

Is it typical to fill the area underneath a concrete/brick stairway completely with base rock? Are there any disadvantages of doing so? Clearly, that area will no longer be accessible or inspectable after it is filled in.

Below are pictures.

Thank you very much for any advice.

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Old 09-17-15, 06:43 PM
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Gee, I wonder where all the broken bricks from the demo are going to end up.....

Seriously, this is typically a place where a lot of construction rubble ends up. I don't think it matters either way if full of stone or rubble or nothing. But let the pros weigh in.
 
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Old 09-17-15, 07:01 PM
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Not a pro but from limited experience hollow is often precast at a factory where special forms and techniques can be used. On site it is just easier/cheaper to fill than build special one time use forms.
 
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Old 09-17-15, 07:53 PM
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The entire stoop doesn't need to be replaced. We can't see the landing in the pic.
 
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Old 09-18-15, 09:50 AM
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Based on the photo, I don't see a need to replace anything.

Other than to re-orient the entire set-up, so users don't have to fight gravity while using the steps.
 
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Old 09-18-15, 10:44 PM
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Thanks for the feedback. The rebar underneath the stairway and landing is corroded, and there are cracks in the cement as well. That is the main reason for replacing it.

The contractor said that they would install #4 rebar every 18 inches on center. The landing is roughly 4.6' x 4.6'. Is every 18 inches too sparse and should the space between rebars be smaller?
 
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Old 09-20-15, 12:23 AM
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How can you tell if embedded rebar is corroded? Did you break into the concrete to determine the extent of corrosion? Also, all concrete cracks. Unless the cracking is extensive, by itself it is not a legitimate reason to remove and replace.

Maybe a few more pix of the areas that cause you concern would be in order. If you're bound and determined to replace the stairway, No. 4 bars at 18" centers is very minimal reinforcement. Rebar carrying significant load stresses should be placed at no less than 12" centers, especially in earthquake country. You would do well to check with your local AHJ, to see if they have some minimum construction standards for what you are proposing to do.
 
 

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