Shiplap is counted by the face you see, so measure your real boards before you trust this count.
How it works
Height ÷ face width gives rows. Rows × wall length plus 10%, then divided by board length.
Before you order
- Measure the exposed face on your actual board. Lumber sizes vary.
- Check level every few rows and adjust gradually.
- Paint the laps first so hairline gaps stay the right color.
Common questions
How wide is a 1×6 shiplap face?
Typically a little over 5 in showing, depending on how much of the board the lap takes. Measure one.
Does shiplap need a backing?
Fasten it to studs or solid blocking. Follow the product directions in wet areas or over fire-rated walls.