how to build concrete footing forms

Question:

what is the best way to build concrete footing forms?

Answer:
Since most concrete footings are buried beneath the ground, their finished appearance is not a concern. For that reason you can use just about anything to do footing forms, even dirt can be used.

There are 4 things of great importance that must be maintained throughout: thickness, center line, flat surface, and width. The thickness will tell you how deep or what size lumber to use.

The footing flat surface has more to do with the foundation wall than anything. A flat top of footings will make foundation wall construction much easier. When it comes to the top of foundations, it's an entirely different matter for the top of the foundation wall must be level, not flat otherwise the framing will be much difficult.

From forming stand point, the only thing important about footing width is to make sure the form will allow the minimum width. Always remember it is better to have slightly bigger footing than too small. If you build your forms 2 or 3 inches wider than what the plans calls for, don't worry about it. On the other hand if your forms are 2 or 3 inches narrower, you might have a problem with the city inspector.

The center line of the footing is important because if your house does not sit on the center line of the footing, it will create structural problems.

As long as you can meet those 4 things mentioned, you're pretty much free to do or use anything to get the desired result.

Old pieces of lumber, cardboards, scrap metal pieces, pieces of boxes or furniture, etc are some of the things I have seen used for forming.

Using of framing material as footing forms is a great way to save money. If you have 10 inch thick footing, you can use 2x10 floor joists or door headers to form your footings and then kept them to be reused in the framing. Should you run out of 2x10s us combinations of 2x4 and 2x6 or whatever combination that can get what needed.

If you use framing material, make sure you don't spray them with release agent as normally done for concrete forms. The release agent will make the lumber flammable making them unfit as framing material. Also remove the framing lumber about 3 hours after the concrete is set. This will minimize the damage to the lumber compared to removing the forms 24 or more hours later. Once the framing lumbers are removed, cover them up to prevent damages caused by heat/sun.