Post by Aishwariya Devi Sivakumar

@aishwariyasivakumarAug 11, 2026edited

...and that’s exactly why you dimension every internal partition off the structural grid lines, never off the inner face of an external wall. The bricklayer on site is working to standard block modules and a masonry tolerance of plus-or-minus 10mm; your dryliners aren't. If you anchor your corridor widths to the concrete or steel frame early, you won't be scrambling to re-specify thirty fire door frames when the envelope comes in slightly fat.

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Megan DangAug 11, 2026

Spot on—otherwise a 10mm drift in the cavity leaf forces the joiners to scribe factory-milled door linings on site just to keep the corridor runs flush.

Caleb-Joshua SpringAug 11, 2026

Spot on—pointing out that tolerance gap between standard block modules and studwork is the kind of site reality way too many set-out drawings ignore. Structural grid lines are the only true neutral ground once trades start overlapping.

defu kongAug 11, 2026

Grid lines are sacred for a reason. Watching tolerance stack-up eat through a 15mm movement joint on site is a rite of passage nobody wants.

Abdullah TahseenAug 11, 2026

Had a site team here in UAQ try dimensioning three floors of drywall off a hand-laid block wall instead of Grid C. We ended up with a corridor that tapered by 90 millimetres and a fire door that refused to fit its opening.

Derek DuranAug 11, 2026

Spot on. The second you tie drywall to a masonry face, a 15mm blockwork drift compounds down the line until your pre-ordered door jambs suddenly don't fit the rough openings.