Glossary
Deck mat
Also called: mat, top mat, deck mat assembly
Reviewed
A deck mat is a pre-assembled unit of deckboards and stringerboards on a block pallet, usually fastened with clinched mat nails, which is then nailed down onto the blocks. Typical mat nails are 1-5/8 in smooth nails clinched over on the underside.
How a deck mat is built
- Lay the top deckboards across the stringerboards.
- Nail through both with mat nails long enough to pass through the stack and be bent over (clinched) on the far side.
- Place the finished mat on the blocks and nail through the stringerboards into each block.
PDS records this as "Mat Assembly Method, Mat Fasteners Clinched" and treats mat nails as their own connection type, separate from top-deck-to-block and bottom-deck-to-block fasteners.
Typical fasteners
| Connection | Typical fastener |
|---|---|
| Mat (deckboard to stringerboard) | 1-5/8 in smooth nail, clinched |
| Top mat to block | 3 in annular nail |
| Bottom deck to block | 2-1/4 in annular nail |
The Uniform Standard requires clinched fasteners to fully penetrate the mat and to be at least 1/4 in longer than the stack thickness.
Why it matters
Clinching locks thin boards together without relying on withdrawal strength, which suits the short penetration into a 3/4 in stringerboard. Building the mat first also keeps board spacing consistent on automated block-pallet lines.
Questions
- Why are mat nails clinched?
- The stack of deckboard and stringerboard is too thin for a straight nail to hold well by withdrawal, so the nail is driven through and bent over to lock the boards together.
Sources
- Uniform Standard for Wood Pallets (NWPCA, now Woodpack Global), 2012 edition
- Guide to Understanding the PDS Specification and Analysis (block class, metric)
- PalletOne: anatomy of the block pallet