How to Measure a Roof Drain: Inside Diameter

Inside drain ring diameter is a common measurement used to help find a replacement roof drain or part, but it is not always the most reliable or consistent.  For this reason, when possible, it is better to use the outside diameter measurement.

Unfortunately, this is not always in the cards, so following is a quick overview on how to properly measure the inside diameter of a roof drain.

Line your tape measure against the inside of the gravel stop, and then measure across 180° to the interior of the opposite gravel stop.

Please note: Do not measure the interior of the ring as show right. This will not yield the correct measurement needed.

If you have any questions, or to order a replacement roof drain, contact Hy-Tech at 000-000-0000 or contact us.