Concrete pad problem

[Hank]

When my modular home was build about four years ago I could not afford to have the full porch addition put on the front so they just poured a concrete pad at the front door. About a year ago I contracted to have the porch added. They poured a concrete porch around the existing smaller pad, adding roof and vynal railings. About a year after installation I noticed new concrete section had settled leaving about a 3/8" drop around the old slab and around the edges of the old slab pieces of the new concrete broke. I finally got the sub-contractor to come out and look at it. He said his crew had made two errors on the job; first they should have drilled rebar into the old pad and extended them into the new pour to tie them together. Second the breakage was because they should have put a special joint where old and new met to prevent adhering and breaking with movement. Admitted problem was his and saying the only way it would look right was to cover it with brick pavers. Total picture is complicated because the contractor I negotiated the job with never fully paid the sub-contractor so he is obviously reluctant to sink any more money into it. Area is in building boom so can not get any one to come and do the small job etc. To make a long story short looks like other than a costly court battle nothing is going to be done. I have patched the broke areas with vynal patch concrete and this has held for two months. I had thought I might be able to just slope the height difference with same patching material so not too noticeable. Then paint porch concrete to get uniform color which is already stained with red clay soil anyway. How about opinions or other suggestions on a way to make it look better. Something a DIY could do.

TIA

TIA email response not expected but to respond remove .uk at end TIA Hank

[Roger Taylor]

Sounds like advice was right. Either the rebar should have been tied into the old pad, or a better, more stable new pad should have been poured over properly prepared ground. That should have included digging down to firm earth, tamping at least a half foot of crushed gravel base for stability and drainage. The 3/8 inch drop is likely to increase, as settling is often a continuous process, especially if no special prep was done for a firm foundation. Any veneer or brick tile will fit for awhile, then likely sink away. I would consider putting a little flexible exterior concrete-colored acrylic caulk in the gap, then taper off the porch with some kind of concrete patch. If the pad continues to settle, you may wish to consider a re-pour. You could do your own research on how to pour a pad, then rent an electric mixer and prep the ground, build the forms, and mix the concrete yourself. Dont forget the fiber joint - usually a 1/2 inch material - to isolate the pad from the porch. With proper foundation prep, there may be no need to tie the pad to the foundation, but do your research on that. Many how-to books at the big box stores on concrete and patio construction.

[DanG]

How big was the first little slab? If small, it should have been removed. If substantial, the man is right - should have been dowelled and control/expansion joints cut or cast at the re-entrant corners. At the very least, it is obvious that there was insufficient subsoil preparation/ compaction.

Solutions now??? Remove the original slab, dowel, and repour. Remove the new slab, dowel, repour, control joint. Mud jacking is expensive. Grinding down the high concrete is a possibility. Bridging (ramping) the change of grade is mildly adequate and may have to be reperformed - only you can decide if the change of grade is acceptable. You can have the entire surface shot blasted, acid etched, or otherwise cleaned and add a thin decorative topping slab. This may be one of the best solutions. The existing breaks would need to be epoxied and a contractor will probably suggest cutting or jointing over any existing cracks and joints as they are prone to transferring into the new surface.

You can see some examples of decorative concrete work here:

and/or

(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) [e-mail]

[Hank]

Thanks for the two replies I got. Must say options suggested seem quite drastic and expensive. Some additional information. Original concrete pad is four foot by ten feet so it is good size. Total size of the porch is now

28 feet long by 8 feet wide. Contractor was quite late in pouring the porch. He was suppose to do it in September (still quite warm here in North Carolina) but did not pour until early December 2003. They dug footings for the cinder block perimeter. Center is filled with crushed small stone. Property slopes so ground level at one end by door is only about 10 inches while at the far end it is close to four feet. Settling is more at the deep end than around the original slab. The 3/8th gap is at the far end as measured to the house. At the original pad gap it is more like an 1/8th inch made very noticeable because movement between the two slabs spaulded out small chunks of new concrete. The settling appeared in Spring of 2004 and although I can not be absolutely sure does not seem to have increased noticeably since then. As a guess I think problem might have been the soil being sort of frozen when work done and changed when warm weather came. I am told that most settling will occur within the first year of construction? As for the slope down from the original slab I don't think it would be that noticeable if I could tapper some concrete to fill the abrupt height difference. If the settlement is not continuing is this a possible approach and if so what would you recommend to bridge the small gap?

email response not expected but to respond remove .uk at end TIA Hank

[Hank]

Thanks for the two replies I got. Must say options suggested seem quite drastic and expensive. Some additional information. Original concrete pad is four foot by ten feet so it is good size. Total size of the porch is now

28 feet long by 8 feet wide. Contractor was quite late in pouring the porch. He was suppose to do it in September (still quite warm here in North Carolina) but did not pour until early December 2003. They dug footings for the cinder block perimeter. Center is filled with crushed small stone. Property slopes so ground level at one end by door is only about 10 inches while at the far end it is close to four feet. Settling is more at the deep end than around the original slab. The 3/8th gap is at the far end as measured to the house. At the original pad gap it is more like an 1/8th inch made very noticeable because movement between the two slabs spaulded out small chunks of new concrete. The settling appeared in Spring of 2004 and although I can not be absolutely sure does not seem to have increased noticeably since then. As a guess I think problem might have been the soil being sort of frozen when work done and changed when warm weather came. I am told that most settling will occur within the first year of construction? As for the slope down from the original slab I don't think it would be that noticeable if I could tapper some concrete to fill the abrupt height difference. If the settlement is not continuing is this a possible approach and if so what would you recommend to bridge the small gap?

email response not expected but to respond remove .uk at end TIA Hank

[Rudy]

Small cracks and fractures 1/8" to ½" wide are often difficult to patch using cement-based products. There's just no way to force the mixture into such a small opening. QUIKRETE® Gray Concrete Crack Seal and QUIKRETE® Concrete Repair Caulk solve this problem. Gray Concrete Crack Seal is a thick liquid that can be poured directly into cracks in walks, slabs and other horizontal surfaces. Concrete Repair Caulk is a textured sealant that can be applied to cracks in walls and other vertical surfaces.