"Attic stock" refers to overage material (typically a finished material) that's not installed. It's kept by the owner in storage (hence the name "attic stock") for their future maintenance crews to use to replace damaged installed product.

Here's an example use case for attic stock:‍

I’m a tile installer and I'm required to deliver an extra 100 SF of 12” white ceramic tile (rounded up to the nearest box) to be kept by the owner’s maintenance crew.

Due to the ongoing maintenance needs and high turnover of residents, attic stock is most commonly required in multi-family residential and hotel projects.  

Usually when attic stock is required, a certain square footage of stock is required for every finished product. So if you use five paint colors, that’s five different attic stock paint buckets. Three tiles? Three different tile boxes.

The quantity of required attic stock is detailed in the specifications (usually 1%-2% of the total installed square footage). If it's not listed, discuss this with your owner/GC to see they want to add attic stock to the spec.

Common trades that need to consider attic stock costs are:

• Flooring
• Tile
• Paint
• Acoustic ceiling
• Finish carpentry (trims)
• Exterior siding (HardiePlank or similar)