Common Plumbing Design Mistakes 11-20
Click on an item below to view additional information and suggestions on how to avoid the mistake .

 11.  Insufficient water pressure for proper operation of fixtures.
            a) At beginning of design, verify minimum & maximum pressures available from water department.
            b) Record minimum & maximum pressures required for all fixtures/equipment within project.
            c) Design booster system where pressure is too low.
            d) Provide pressure regulating valves where pressure is too high.
 12.  Neglecting to specify anti-scald shower valves.
            a) Specify pressure-balancing or thermostatic type shower valves for all showers.
 13.  Lack of information on drawings or specifications requiring shower drain pans.
            a) Verify and comply with applicable local code requirements.
            b) Insure that either architectural or plumbing specifications/drawings clearly require drain pans for
                 all non-monolithic shower stalls.
 14.  No provisions on drawings for emergency overflow drainage on roofs having parapets.
            a) Verify and comply with applicable local code requirements.
            b) Coordinate with architect and verify roof type and construction.
            c) Design overflow scuppers or secondary drainage system for roof areas.
 15.  Failure to provide approved backflow prevention at fixtures and equipment.
            a) Verify and comply with applicable local code requirements.
            b) Refer to fixture & equipment manufacturers installation data and verify backflow requirements.
            c) Clearly indicate on drawings which equipment requires backflow prevention and specify code required type.
 16.  Omission of deep trench safety shoring within documents.
            a) Include statement on drawings directing contractor to follow OSHA guidlines for trench safety.
            b) Refer to the following web based OSHA information.
 17.  Specifying equipment with voltages not compatible with available sevice.
            a) Coordinate with electrical engineer and verify voltages and phasing available and preferred.
            b) Review related elec/plbg coordination information at...RepWars-Intelligence Reports.
            c) Download this electrical/plumbing coordination form to obtain input from electrical engineer.
 18.  Not specifying equipment/fixtures preferred by owner.
            a) Coordinate with owner and list preferred fixtures, equipment and material.
            b) Download this fixture/equipment coordination checklist to obtain input from owner.
 19.  Unclear requirement or preference for fire sprinkler alarm zoning.
            a) Coordinate with owner and fire alarm consultant to determine proper alrm zoning.
            b) Indicate zoning requirements on drawings and/or within specifications for each flow and tamper switch proposed.
 20.  Failing to provide proper water treatment.
            a) Obtain water quality information from water department or lab.
            b) Determine water quality required for all fixtures/equipment to insure proper operation and warranty compliance.
            c) Coordinate with owner and determine water quality preference or requirements for the facility.