Hi. Can any one give me some good advice on repairing a small concrete area I need to do? I’ve got lots of questions, so bear with me here.
I am installing an iron step railing to go up a set of steps – but before they install it, I want to repair the bottom area where the first railing post will be attached. This bottom area is cracked and has sunken down 1.25 inches at the lowest corner by the step next to that garden raised border. The area that I want to replace is the triangular shaped area in the photo that is bounded by the garden raised border, the step, and that gently curved crack. When I dig out that area should I smooth the crack’s rough edges some with my diamond grinder blade? Should I undercut that edge some?
If possible I would like to match the old concrete, which is original to the house. This existing concrete has those small pebbles that they used to put in the concrete mix as aggregate. Should I buy pre-mixed and add those pebbles? Wouldn’t that be changing the mix proportions and then affecting the integrity of the mix? Or do I buy each component of concrete, meaning the sand, the portland cement, and the aggregate, and then mix that in the correct proportions? How do I “tie” the new pad to the old? I have several 24″ long 7/16″ diameter rebar that I will sink into the pad. How should I prepare the base below the new concrete? That control groove is an existing groove in the concrete that is about 1/8″ deep. Some friends have told me to cut out the whole area up to that groove but I don’t want to because it means more concrete and frankly that part is in great shape and I don’t want to fix what ain’t broke, if ya know what I mean.
The straight sides of the pad are 32 inches long.
Thanks to everyone in advance!
Replies
Your friends are right... cut it out up to the control groove and replace it. Add some depth to it and some rebar too. While you are at it drill some holes horizontal into the edge of the near slab and into the footer of the stairs and jam some short rebar pieces into them too (this will stabilize the new slab against shearing out of relation to these surfaces).
Looks like water was trapped there and may be the cause of the settling. Might want to try to correct this when you do your fix.
Pack down the ground good before repouring. The watering of the flower bed and slope of the ground surely is what caused the problem in the first place.
Do you have any steel plate you could drive in the ground, edgewise, there on that right hand edge by the flower bed? That might prevent the soil under the new concrete from sluffing down in the future.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
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