|長手|
daijr:  材の寸法の長い方の側。
shinmeikai: （曲尺の）長い方。
https://doboku.ezwords.net/yougo/長手.html
"長方形の長いほう"
---
|stretcher|
Oxford: brick or stone laid with its long side along the face of a wall.
M-W: a: a brick or stone laid with its length parallel to the face of the wall
     b: a timber or rod used especially when horizontal as a tie in framed work
Wiktionary: A piece of timber used in building.

I don't think "stretcher" is correct, despite what GG5 and the terminology dictionaries say. No English dictionary defines "stretcher" as "the long side of ..."

@@ -16,0 +17 @@
+<gloss>fairly long</gloss>
@@ -21,2 +22 @@
-<gloss>stretcher</gloss>
-<gloss g_type="expl">long side of timber (etc.), or a timber placed lengthwise</gloss>
+<gloss>long side (of timber, etc.)</gloss>

jaanus, gg5

@@ -12,0 +12,1 @@
+<pos>&n;</pos>
@@ -18,2 +19,3 @@
-<gloss>longer side</gloss>
-<gloss>stretcher (building)</gloss>
+<field>&archit;</field>
+<gloss>stretcher</gloss>
+<gloss g_type="expl">long side of timber (etc.), or a timber placed lengthwise</gloss>

紙器関係専門用語辞典, 土木用語辞典, daij

is the "stretcher (building)" supposed to mean "A brick laid 
with the longest side exposed (compare header)" ? (wiktionary)

if so maybe it should read "stretcher (brick)" instead

@@ -18,0 +18,1 @@
+<gloss>longer side</gloss>
@@ -20,0 +21,5 @@
+<sense>
+<pos>&n;</pos>
+<misc>&arch;</misc>
+<gloss>long road</gloss>
+</sense>

Kojien
1.遠い道。長途。ながち。
2.長めなこと。長い方のもの。

Here's the sentence I came across in an email from a Japanese coworker:
立ち上げ当初に設備輸送した際、高さ・幅がギリギリで、かつ、長手方向に長いものコンテナのまま納入して、引き出すのに非常に苦労した経験があります。
JB: rewrote as in GG5