Brick Veneer Weep-Hole Count (IRC R703.8.6)
Weep holes to drain the veneer air space at each through-wall flashing line.
Example
You enter
- Wall / flashing length (ft) 30
- Max weep spacing (in, code cap 33) 33
- Flashing lines (base + lintels) 1
You get
- Weeps per flashing line 12
- Total weep holes 12
Details, formula, and sources
Weeps per line = ceil(wall length in / max spacing) + 1, so both ends get a weep. IRC R703.8.6 and TMS 402 cap the spacing at 33 in on center (a common tighter spec is 24 in), at least 3/16 in diameter, immediately above the flashing. A 30 ft wall at 33 in is 12 weeps per line; the base course plus every shelf angle and lintel flashing above openings each need their own line. The weeps must sit directly on the flashing over a clear, un-mortar-clogged air space; the AHJ-adopted code and the wall detail govern. Distinct from the veneer ANCHOR count.
weeps_per_line = ceil(wall_length_ft x 12 / max_spacing_in) + 1; total_weeps = weeps_per_line x round(flashing_lines).
IRC R703.8.6 and TMS 402 masonry-veneer weep-hole provisions, by name; the spacing cap and detail come from the adopted code.
The count arithmetic is public first-principles; the 33 in spacing cap, 3/16 in minimum diameter, and above-flashing placement are in IRC R703.8.6 (many jurisdictions post the adopted IRC).
Estimate. AHJ and licensed professional govern.
Field names used by the API: wall_length_ft, max_spacing_in, flashing_lines, weeps_per_line, total_weeps
- Spacing cap IRC R703.8.6 / TMS 402: <= 33 in o.c. (24 in a common tighter spec), >= 3/16 in diameter, above the flashingIRC R703.8.6
- Per flashing line count is per through-wall flashing line; base course plus each shelf-angle/lintel line needs its own weepsmasonry veneer detailing