That job at the Denver high-rise changed my mind about rail alignment specs

I used to think the old standard of plus or minus 1/16 inch was fine for door rail alignment. Never had issues with it for years. Then we got a call about a brand new Otis install in a 42-story building downtown Denver. Doors kept sticking on floors 18 through 24 during peak hours. After three days of chasing it, I finally checked the rails with a digital level and found the spec was way too loose for that building's thermal swing. The super insisted we tighten it to 1/32 and the problem vanished. Now I wonder why nobody pushes for tighter tolerances on high traffic jobs. Anyone else run into buildings where the standard specs just don't cut it?

3 comments

3 Comments

mark_green17d ago

That 1/16th spec has been the standard forever (like, since my dad was in the trade) and I've never seen a door stick because of it. I gotta wonder if it was really the rail alignment or if you maybe had a thermal expansion issue with the door itself, not the track. Pulling it tighter to 1/32 sounds like a bandaid for a building that probably has a bigger problem with its structure shifting or the HVAC being uneven on those floors. Plus, tightening the tolerance that much just makes future adjustments a nightmare for the next guy who has to work on it in colder weather. Seems like overkill for a problem that coulda been fixed with some lube and a door closer adjustment.

fionafoster17d ago

Yeah, I was the same way until it happened to me too.

ray_sullivan17d ago

@fionafoster I respectfully disagree, Mark - I've personally seen that 1/16" gap cause sticking on three different jobs this year.