Concrete footings - Contractor Talk - Professional Construction and Remodeling Forum

primetimeon · 08-20-2009, 09:08 PM

Hey guys
quick question for you, How long should you wait to start building on new footings.

Clay soil, southern california 12"x2'

thanks for your help.

dakzaag · 08-20-2009, 09:13 PM

Concrete cures for about 28 days.

cleveman · 08-21-2009, 07:08 AM

You can start right after you strip the forms.

thom · 08-21-2009, 09:09 AM

I've seen guys start within a couple hours of the pour.

It's really a function of time and stress. If you are setting block, you can start almost right away. If you need to drive a truck over it, you might want to wait a little longer.

concretemasonry · 08-21-2009, 10:59 AM

The 28 days is just an old wife's tale. Concrete actually cures for years. It cures the fastest in the first couple of days and slower later on. The 28 days only refers to one of the time dates (7, 14, 28 and 56 days) for cylinders to check the concrete mix under lab curing conditions.

Depending on the load, loads can be placed on it almost immediately.

I frequently see the first course or two of block for a basement laid the afternoon of the pour. This is done to make sure any rain does not swamp the basement footings and depositing dirt/mud that can take a long time (and money) to clean when the discovered the next day. Anything in an excavation can get very messy and unworkable and delay anything.

A typical basement footing or trench type footing has very little load on it until the structure is up and backfilled. If it is a trench type footing with not unbalanced soil, backfilling improves the curing conditions.

scrapecc · 08-21-2009, 02:52 PM

Quote:

Originally Posted by concretemasonry

The 28 days is just an old wife's tale. Concrete actually cures for years. It cures the fastest in the first couple of days and slower later on. The 28 days only refers to one of the time dates (7, 14, 28 and 56 days) for cylinders to check the concrete mix under lab curing conditions.

Depending on the load, loads can be placed on it almost immediately.

I frequently see the first course or two of block for a basement laid the afternoon of the pour. This is done to make sure any rain does not swamp the basement footings and depositing dirt/mud that can take a long time (and money) to clean when the discovered the next day. Anything in an excavation can get very messy and unworkable and delay anything.

A typical basement footing or trench type footing has very little load on it until the structure is up and backfilled. If it is a trench type footing with not unbalanced soil, backfilling improves the curing conditions.

+1

dakzaag · 08-21-2009, 04:13 PM

A GC who wants to know how long til he can put stress on a footer.

You might be a lot of things, but a primetime GC your not.

Sorry, but I learned that about 2 weeks into my first construction job, and I was an unskilled laborer at the time.

Still considered unskilled by some...