% of recycled content in steel Rebar

There is no minimum value. Any percentage recycled content can contribute to the overall recycled content for the project that is arrived at via the formulas for MRc4. Please see Equations 1 and 2 in the LEED Reference Guide for Green Building Design and Construction (page 372 of first edition).

Mahbuba, Steel rebar is one of the primary materials, experienced LEED professionals know, that has high inherent recycled content. It is lower strength steel, used in tension applications and not compression. That means it can have higher recycled content than other steel materials. For my projects, in the Southwestern U.S., the recycled content for steel has always exceeded 95% overall, with most of that being post-consumer content. Sources for rebar my projects have used have ranged from Taiwan, to Mexico, to the Pacific Northwest U.S., and to the Southeastern U.S.

I have a further question to the Steel Rebar question for recycled content. If: 97.8% of the Rebar is Total Scrap Steel and 2.2% is comprised of Total Alloys and Other Iron Units = 100% And: 81.1% is Post-Consumer and 16.7% is Pre-Consumer How do I calculate the Pre & Post-Consumer content? If I take a straight 81.1% Post and 16.6% Pre, then it does not take into account that only 97.8% of the rebar is recycled content. Thus, am I supposed to take: 97.8% x 81.1%= 79% Post and 97.8% x 16.6%= 16% Pre Though it doesn't make much of a difference when the total recycled content is 97.8%, it would make a huge difference if the total recycled content were only 25%. However, I cannot find anything in the Reference Guide or anywhere else that references how to document these situations. Or is this why everyone just takes a default 25.5% recycled content for steel products?

Jennifer I believe you're over thinking this one. The pre- and post- percentages listed are a breakdown of the 97.8%. 81.1+16.6 = 97.7%. So use the 81.1 and 16.6 directly in the calculations. The 0.1% difference is a rounding error.

Thanks Keith for chiming in. Jennifer - As Keith notes, use the pre- and post-consumer values above in Equation 1 in the LEED Reference Guide to get the overall recycled content value for the rebar.