Problems with Concrete Driveway Installation in the Rain

Immediately After the Pour

• Concrete is most susceptible to rain damage before it begins to set usually about three hours after the pour. During this time, efforts should be made to shield the cement from rain. Use a trowel of float to remove any water that accumulates on the slab. Another trick is to drag a garden hose across the surface of the slab to pull the water off the slab and clear of the cement. Add dry cement to the wet mix in an effort to absorb water.

After the Cement Sets

• Damage from rain can continue after the concrete sets. Even after the cement has received its final trowel finish it can receive surface damage from rain. After the finish work is done on the cement, place plastic sheeting over the slab to prevent rain damage.

Slab Damage

• Rain damage to the driveway slab can be limited to cosmetic surface washing or it can involve structural damage that can affect the durability and usability of the slab. Unfortunately, this usually means engineering lab testing. One simple test is to strike the questionable cement slab with a cold chisel and observe the results. Compare the results to a similar chisel strike to a known good concrete surface. The level of damage to the slab is controlled by the amount of rain that fell on the slab, when the rain fell in relation to the curing process, how effective slab protection measures were and if proper cement finishing, including power troweling and vibration, were accomplished.