Species guide
White Ash and Black Ash: what the numbers tell you.
How White Ash and Black Ash differ in published wood data.
Direct answer
NWFA lists a Janka number of 1320 for White Ash and 850 for Black Ash. One “Ash” number can hide a real difference. These are test figures, not promises about one floor.
See the wood, then read the numbers
A photo can show character. It cannot prove the species.
Use the measured record below to compare the named wood. Then compare real samples in the room where the floor will live.
How to read these figures
The source lists White and Black Ash separately. Keep them separate when you compare wood. An older source also mentions emerald ash borer. It cannot tell us what is in stock today.
Sources & methodology Peer-reviewed measurements and study context
These figures come from clear-wood laboratory data in the cited peer-reviewed study. They help you compare species; your own floor’s construction, finish history, and condition still matter.
| Metric | Reported value | Context |
|---|---|---|
| White Ash NWFA Janka value | 1320 | Published separately from Black Ash. |
| Black Ash NWFA Janka value | 850 | Published separately from White Ash. |
| Specific gravity | 0.55 White Ash / 0.45 Black Ash | NWFA published figures. |
| Shrinkage from green to oven dry | 4.9/7.8% White Ash; 5.0/7.8% Black Ash | Radial/tangential figures from NWFA. |
Reviewed October 6, 2026. The paper measures clear wood in a lab. At your visit, we look at the real floor, room, and project plan.