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.
Skylight Leaks. If your skylight leaks, chances are good that the problem is the seal between the flashing and the roof. Identifying where the leak is originating is the first step. For more about troubleshooting a roof leak, please see How to Find & Fix a Roof Leak.or this, you can use the same roofing cement. 4 Also check the seal where the skylightâs glass meets the frame. If you see any signs of leaking, seal this with clear silicone caulk. Keep in mind that some skylights, notably those in bathrooms, can drip moisture from condensation.