Contractor says that concrete will crack, period. I say there should be a better way.?

Question

Anyone have any luck keeping concrete crack free? I put a hot tub on a pad 5-6" thick and after 5 years no crack. My driveway, same thickness is cracking all over the place. Does sealing help?

Answer 1

Yes, sealing does help. Wait for warm-dry weather. The object is to get all the water out of the concrete and then prevent more water from getting into the concrete. Water gets into the gaps between the sand and cement in the concrete, and as it freezes, it expands and slowly pushes the concrete apart from the inside. The object is to keep the water out so you reduce the freeze-thaw cycle.

But this will not compensate for settling soil. If you have unstable soil under the patio, you may want to consider reinforced concrete with iron rebar.

Answer 2

Your driveway is probably cracking because the ground under it settled. It just happens. If you look at an old sidewalk you'll see that the individual sections are no longer perfectly level with each other. That's why sidewalks are poured in sections--to minimize cracking that will occur with the freeze thaw cycle.

The pad you put your hot tub on is fairly small and probably has room to expand and contract a little. A driveway is fairly long and wide and there's more ground under it to settle.

I live in an area where we have a lot of heat in the summer and it gets cold in the winter. Every concrete driveway I've seen has had cracks from that and the shale that underlies it shifting. That's why when we lived in the country we had a packed and rolled gravel driveway. It would give and take with the soil shifts and could be fixed every few years by a little more gravel and rolling it again.

Answer 3

The contractor is correct, concrete will crack. Adding extra joints to the concrete will tend to make it crack along the joints and less likely to crack in other areas. Applying a good curing compound will also help. A sealer applied latter on will seal the cracks and keep water from making the cracks bigger.

Answer 4

Are there administration joints interior the concrete? This slab is in simple terms too great for there to not be. it would surely crack with none joints. It sounds like the subgrade wasn't compacted sufficient and there is settling, which in turn, is inflicting the concrete to settle and crack. I trust between the previous solutions - checklist the heck out of this concrete. Take as many pictures as you may and save each and all the written/telephone conversations. If it became built incorrectly, it extremely is the contractors duty to restoration it. it can be a stable thought to communicate with a felony expert and function them evaluate your settlement with the contractor.

Answer 5

The concrete on your driveway is subject to alot more variables in weight and weather than the slab for your hot tub. Rain water and the weather have alot to do with cracking. Putting a sealer on might work, but I would not gaurantee it.

Answer 6

Depends on the aggregate in the mix along with the amount of water added before pouring. Concrete is graded into slump catagories and the "slump" can be changed by adding more water. In certain conditions this can cause weaker concrete. The same applies if the sand/gravel/cement ratio is off.

Answer 7

Depends on the size of the slab. You need expansion joints about every 8-10 feet. If your hot tub pad is smaller than that, it may not crack at all, or very soon.

Answer 8

Joint spacing, the weather & the base prep will all affect the outcome. There is no guarantee that concrete will not crack even with every thing done the correct way.