# Can you substitute one 3/8" rebar by three 1/4" rebars?

[This question is about constructing techniques in Brazil, so if anything is not clear or not properly worded, please let me know and/or suggest phrasing improvements]

I am building the foundations for the railings which will separate my plot of land from my neighbour. The foundations will be built with concrete blocks and reinforced with metal bars. The standard rebar size to be used is 3/8". However, I have some leftover 1/4" bars from my house which I would like to use.

So here's my thought process: up to some constant, the cross section area covered by a 3/8" bar is 9/64 (~0.14) square inches, whereas for a 1/4" bar it is 1/16=4/64 square inches. Two 1/4" bars would cover 8/64, and three bars would cover 12/64 square inches, which is more than the one 3/8" bar would.

Is my thought process correct? Similarly, could I use one 1/4 and one 5/16" bars (covering ~0.16 square inches) instead of the one 3/8" bar?

• For what you want, basically a fence instead of something like a building, it should not matter. Besides the diameter/sq. in difference, a 3/8 rebar is stronger than a 1/4 rebar(or three 1/4 inch rebar). Commented Feb 8 at 0:55
• Seems that this would be determined by your local building codes. What does your local building department/building inspector have to say about it? Commented Feb 8 at 12:53
• @crip659 what's your reasoning for one 3/8" being stronger than three 1/4"? Commented Feb 8 at 13:24