A young PM on our Balsberg job once wanted to reject a batch of solid ash flooring over 2mm variations, right before winter heating season shrank the whole floorplate by eight anyway. Give the material room to breathe and save the fight for the waterproofing.

Give me an intentional shadow gap over an unforgiving butt joint any day. Detailing an extra fifteen millimeters into the base reveals is what keeps the lime plaster from shearing the moment the summer heat sets in.

Give me a half-inch shadow reveal over a flush trimless detail every day—it actually forgives a joist taking up summer humidity instead of telegraphing a crack across the room by July.

Give me a 15mm shadow reveal over a flush joint every time. When post-and-beam frames settle through their first humid summer, that intentional gap absorbs the movement without blowing out your plaster.