Ask the Builder: Getting your building foundation right
Recently a 75-year-old man submitted a question on the Ask Tim page at AsktheBuilder.com. I get quite a few each week and answer each one. This particular question put a huge smile on my face because it screamed “Attitude.”
Connie — yes, it can be a name for a man — wrote: "I am going to attempt to build my home myself using some subs to do various work. I am going to do the footing and foundation. How do I lay out my batter boards with a string line to make sure my piers are all straight and in line?"
Can you imagine the excitement he’s feeling about starting this project? Don’t you love a positive attitude like this? To be sure it needs to be mixed with realism as to what he can do physically.
I was immediately reminded of Harry Andrews, who built the one-of-a-kind Loveland Castle along the banks of the Little Miami River in a suburb of Cincinnati. Harry set a goal in 1927 nearly a decade after serving in World War I. He decided to build the massive castle and continued to add stone after stone until his death in 1981.
While Connie’s house dream is much more modest, I admire people who set goals and do their best to achieve them. We should all take a lesson from Connie and Harry!
Connie asked a few of the right questions, but he didn’t touch on a few really important ones about what needs to be done when you decided to build a foundation. Let’s start to unpack the process, and I’ll share some of the common pitfalls I see many professional builders make.
The height of the foundation is perhaps one of the most important things to consider. All too often I do autopsies on water-infiltration issues homeowners suffer because the top of their foundation is too close to the ground surrounding the house. Drive through older neighborhoods near you, and you'll see the tops of the foundations typically 30 or more inches up out of the ground!
The building code — which happens to be a set of minimum standards — states that the top of the foundation must be no less than 4 or 6 inches above the ground that touches the foundation. But wait, there’s more! The ground must then slope away from the foundation a minimum of 6 inches within the first 10 feet of horizontal distance from the foundation. Confused?
What this means is that your foundation should simply mimic the top of a hill where all the ground around the foundation slopes away so you have great water drainage and surface water doesn’t flow toward the house. Remember, the numbers above are minimum requirements. You can create more fall if you want.
In my opinion, the next most important step is to make sure the foundation is square. Connie didn’t mention this, but I’m sure he’s aware of it. You were taught how to do this all those years ago in high school geometry class. Remember when you grumbled under your breath sitting at your desk saying, “When am I EVER going to use this silly formula about right triangles?” Well, today is the day.