Advice on enlarging concrete bottom step

[Wayne Whitney]

Hello,

I'm redoing my front porch stairs, the old stringers were encased in the concrete bottom step, not a good thing. I want to bolt a board to the top of the concrete and notch the bottom of the stringers to meet the board.

So I need to somewhat enlarge the step. It is about 66" L x 16" W x

12" D. The back side of the step is all rough concrete with large aggregate. The top of the step is a greyish material without aggregate; it is somewhat chipped and not particularly flat, so it could use redoing. Here's the procedure I've come up with, I'm looking for any comments or suggestions:

Remove any loose soil behind the step. Clean the backside of the step with a hose and brush. Drill 4 holes 6" deep into the back side of the step and epoxy in some 9" #4 rebar stubs projecting out 3". Form up to extend the step 5" (providing 2" cover on the rebar ends). Mix and pour 4-5 0.45 ft^3 bags of sacked concrete, poking it into all the voids. Leave the new concrete about 1" below the finish surface and allow to cure a day. Chisel the the top of the old step to roughen it up and remove 1/2" to 1" of material. Mix some non-shrink grout (e.g. CementAll) and pour a smooth finish surface at the desired pitch and elevation.

Thanks, Wayne

[BobK207]

Wayne-

Sounds fine....I would add some cement to the sackrete or use the CementAll stuff in the green bag...not cheap but hardens harder & faster

cheers Bob

[Wayne Whitney]

You know, that is what everybody says, but why? Sakrete claims their "High Strength Concrete Mix" has a 28 day strength of 4000 psi. Is that not adequate? I will pay attention to the amount of water, I understand it is common to use too much.

Thanks, Wayne

[BobK207]