When Can You Backfill a Foundation?

Let the concrete cure for at least a week before backfilling (28 days is best). Place and compact the backfill carefully in partial lifts—don't dump it all in at once. And if you have to backfill before the floor system is framed, support the walls first with sturdy diagonal bracing.

How long before you can backfill a foundation?

The backfilling of foundation walls should ideally be done only after the concrete has had time to fully cure. Concrete foundation walls are defined as being 75% cured after 5-7 days, and fully cured after 28 days, under ideal temperature conditions.

How high can you backfill a foundation?

First, keep the height of the backfill to no more than 4' except at the corners or offsets until the deck is in place. Four feet of unbalanced backfill will usually not exert sufficient pressure to damage the wall.