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.
9 Causes of Leaky Windows. One of the main reasons to ensure your windows are watertight is to keep moisture out of the walls. Once inside your walls, moisture can cause rot, mold and pest problems. Keeping water at bay would be easier, of course, if our homes had no openings for doors and windows.
The initial dangers of a roof leak are damage to the attic area and items stored there. If there is no attic, or the size of the leak is really big, it will damage the interior ceiling. Affected ceiling paint will darken and ceiling plaster may bubble and expand.