The Greenstone Home Reference mark: a square quarry tile carrying the letters G R.

Greenstone Home Reference

Working notes on repairing, insulating and upgrading older masonry houses.

Nominal lumber sizes

Softwood is sold by a nominal call-out that describes the size before it was dried and surfaced, not the size you receive. The difference is consistent enough to work from.

Nominal call-outs against actual surfaced dimensions. Units: inches.
Nominal call-outActual surfaced size
1 x 23/4 x 1 1/2
1 x 43/4 x 3 1/2
1 x 63/4 x 5 1/2
1 x 83/4 x 7 1/4
1 x 103/4 x 9 1/4
1 x 123/4 x 11 1/4
2 x 21 1/2 x 1 1/2
2 x 41 1/2 x 3 1/2
2 x 61 1/2 x 5 1/2
2 x 81 1/2 x 7 1/4
2 x 101 1/2 x 9 1/4
2 x 121 1/2 x 11 1/4
4 x 43 1/2 x 3 1/2
6 x 65 1/2 x 5 1/2

Notes on using this sheet

  • The nominal figure describes the rough sawn green section. Drying and surfacing on four sides remove the difference.
  • Above nine inches nominal, the reduction is a quarter rather than a half inch, which is the step most often forgotten when setting out.
  • Rough sawn stock sold undressed is closer to its nominal size and will not match dressed material in the same run.