Why does EMSEAL discourage the use of gutters under deck expansion joints?
There are several reasons not to use gutters under joint systems: 1) The gutter conceals any leaks. The leaks go undetected. The structure corrodes. Once water (carrying salts and other corrosion causing chemicals) has bypassed the primary joint system, costly and dangerous degradation of the structure begins. This is because water runs over the concrete on its way to the gutter. During this passage it will make its way to the rebar. The rebar will corrode, expand, and spall the concrete. 2) Gutters are not water proofing, they are water management. Water that reaches a gutter must be managed to drains. To do this gutters must be pitched to ensure drainage. The gutters must be dammed at ends and be fabricated to be watertight at plane and direction changes. Joint systems are too often detailed in cross-section only. In cross-section a gutter looks effective. Joints detailed in cross-section will not get constructed either with pitch or with terminations, transitions, or integration int
