monolithic pour backfill

by VJ

Question:

Do you backfill monolithic pours?

Answer:

When it comes to concrete monolithic pours, there are two types of backfilling. One is during the preparation stage as excavations take place. Obviously excavation will not come out exactly what you want or planned especially if you are dealing with sandy soil or gravel type material. In these types of instances it will be difficult to have thickened edge slabs pours without a lot of concrete waste.

You can certainly put some temporary forms in so you can backfill and then pull them out during the pour. If you go this route, the forms must be removed during the pour, you don't want to leave the wood in to rot over time creating ground settlements. The other thing to consider about this route is it requires a lot of labor not only to do the form but to do the back filling and compaction.

If you are building a 24ft x 30ft garage, you can calculate the amount of concrete waste. What you will find is the amount of concrete waste will be around 2 to 3 yards max that will cost at most $300. When you consider the material and labor to do the additional work, you will spend a lot more on top of so much headaches because it will be very difficult to make it exactly right. For that reason, I buy the extra 2 or 3 yards and never have to worry about it.

If you do decide to go with backfilling, I recommend using pea gravel so that you don't have to compact. Compacting unstable newly excavated soil will create more problems than you already have.

The other type of backfilling is followed after the perimeter form work is removed. In this type of backfilling, it is a must.

Hope this helps
Tonga