Concrete Foundation

[bigb6162]

I have a delima. I am building in East Texas and my lot is sloped 10 feet from the front to back. The foundation pad ( fill ) is zero feet ( Natural Grade ) at the front of the house and about 6-8 feet at the rear. I want to pour a monolithic slab due to costs. The footers are 16" x 20". I was thinking of beefing up the footer on the rear to 16x48" and possible core drilling peirs 12 foot deep by 12" round in all the corners of the house. Any suggestions?

[Wgoodrich]

YOU SAID;
I am building in East Texas and my lot is sloped 10 feet from the front to back. The foundation pad ( fill ) is zero feet ( Natural Grade ) at the front of the house and about 6-8 feet at the rear.

REPLY;

The Code requires your finished grade to slope a minimum of 6" in 10' all the way around that house. You say your one side of the house is natural grade yet you say you hat a slop from front to rear about 10'. Be aware that the house on the high side of your land must have a slope away from the house so that the water coming down that slope does not run against the house rather drains away from the house in all directions. Otherwise you will have moisture problems even mold problems most commonly found when that fall all the way around the house is not present.

YOU SAID;

I want to pour a monolithic slab due to costs. The footers are 16" x 20". I was thinking of beefing up the footer on the rear to 16x48"

REPLY;

In your area discribed your frost concern is just at freezing being 32 degrees. The depth and width of your foooter being 16" deep and 20" wide sound fine to support a one or two story building and meet frost depth concerns. Be aware that all footers must be designed so the bottom of that footer is at least 12" below undisturbed dirt and at least deep enough to meet or exceed the expected frost depth in your area.

YOU SAID;

and possible core drilling peirs 12 foot deep by 12" round in all the corners of the house.

REPLY;

Why 12 feet deep? Are you next to a slope that is more than a 45 degee slope inviting errosion mud slide concern? If this is the case you need a set back from that slope a minimum of 5' for each 5 degrees more than the 45 degree slope. You would have an option to bore piers to the elevation equal to the bottom of that slope but those peris would have to be placed no further apart than the ability of your girders to span to carry the house. Your last statement causes some concerns.

Your footer to support that home is 2 story or less on sand or gravel is only 16" wide and placed below the frost line in your area. Why the overkill in your thoughts?

Good Luck

Wg

[Under_Miner]

Being from Texas, I'm wondering if frost is really a concern. I'm assuming you're using the piers for uplift as well as support, is there a great deal of clay in the soil where you come from?? If so, the piles are a great idea, but more may be needed. If plasitic soil isn't a concern in your area then, as Goodrich mentioned, the piles would be just a waste of money.