§1When it's worth it
When a shortage would stop shipping; when one supplier has a single plant; when your volume is large enough that a second supplier will take it seriously; and when supply is tight (for example, when lumber or core prices are rising fast).
§2How to split
A common pattern is a primary supplier with most of the volume and a secondary with enough that it keeps your spec on its schedule. Splitting by delivery point is cleaner than splitting the same dock between two suppliers.
§3Keeping the backup ready
Give the secondary a written surge commitment (how many extra pallets at what notice), test it once a year, and inspect its deliveries with the same plan as the primary's. Use the same spec sheet and the same index clause, so prices stay comparable.
§4Use market data
The state supply market pages show pallet plant counts and employment from BLS QCEW. A state with few plants means fewer options inside a sensible delivery radius; look across the border too.
§5How to split the volume
A common pattern is a primary supplier with most of the volume and a secondary with enough to keep it engaged and familiar with your spec. The secondary needs regular orders; a supplier that sees you twice a year will not hold capacity for you when the primary fails.
Split by delivery point where you can. Giving each supplier the sites nearest its plant keeps freight down and makes quality problems easier to trace.
§6What it costs
Dual sourcing usually means a slightly higher average price, because each supplier quotes on less volume. Set that against the cost of a line stoppage or an emergency buy at spot prices. The state supply market pages show how many plants operate near each delivery point, which tells you whether a second local supplier exists.