Installing proper plumbing drains call for a minimum 2% grade of slope. The Swanson® multiple ring vials offer an easy way to approximately determine the correct needed slope.
When the outside edge of the bubble touches the second ring of the vial it is measuring an approximate 1/8″ slope over 1 foot of run, which is a 2% grade.
When the bubble touches the third ring it is measuring an approximate 1/4″ of slope over 1 foot of run, which is a 4% grade.
Please check with your municipality to make sure your design complies with all building codes.
Swanson® Building Customer Trust for more than 80 years®. Multi-Ring Vials To see other project and tool tips Go to http://www.swansontoolco.com/swanson_tips.cfm