An Ordnance Survey cut mark in the UK. The term bench mark, or benchmark, originates from the chiseled horizontal marks that surveyors made in stone structures, into which an angle-iron could be placed to form a bench for a leveling rod, thus ensuring that a leveling rod could be accurately repositioned in the same place in the future.
The forces that cause windows to leak fall into three categories: house design, installation, and maintenance. Turning to the wisdom of industry experts, we can identify nine of the most common errors that occur during window installations, which can lead to window leaks â and now you can too.
cause. Frequently, inspection of the surround will reveal damage done to the framing thru installation or abuse so that the glass is stressed near its breaking point and a subsequent movement, or temperature change forces that glass to yield. 9. Accidental or deliberate vandalism can be another cause of unexplained breakage.