0:09for the purpose of retrofit sub soil
0:12drainage commonly referred to as
0:14basement waterproofing the Minnesota
0:16uniform plumbing code specifies drainage
0:18conduit with a minimum three inch
0:20diameter the code also gives officials
0:23the authority to allow other types of
0:25drainage conduit as long as they meet
0:27the minimum standard here we will
0:30examine the size of the opening flow
0:32rate and holding capacity of four
0:34different types of drainage conduit the
0:37intent is to suggest a way to determine
0:39if an alternative type of drainage
0:41conduit meets or exceeds the minimum
0:44code will also consider performance
0:46characteristics based on how the
0:48different styles of drainage conduit are
0:50installed we will use standard flow
0:52rates as found in manufacturers
0:54published documents where available
0:56three-inch corrugated drainage conduit
0:59with an opening of 7.06 square inches
1:02has a flow rate of 35 gallons per minute
1:04the corrugations caused friction as the
1:07water flows through affecting flow rate
1:09the corrugations also hold water so it
1:11does not drain completely plus it’s
1:13flexible which makes it difficult to
1:16install at a continuous downhill slope
1:18once again affecting flow rate the
1:20holding capacity is one and
1:22three-quarters leaders three inch rigid
1:26PVC drainage conduit also with an
1:29opening of 7.06 square inches has a flow
1:32rate of about forty four gallons per
1:34minute it follows a smooth downward
1:36slope to the sump basin and drains
1:38completely the holding capacity of a one
1:40foot section of three inch PVC drainage
1:42conduit is one and one half liters the
1:46in slab drainage conduit is a
1:48proprietary product and has no published
1:50flow rate its opening is approximately
1:525.25 square inches because it sits on a
1:56footing which is supposed to be level it
1:58will have a lower flow rate than either
2:00three inch corrugated or three inch
2:02rigid PVC drainage conduit also it may
2:05not drain completely due to the lack of
2:07a downhill slope the holding capacity is
2:09just over one liter2:11the multi flow drainage conduit has a
2:14published flow rate of twenty nine
2:15gallons per minute each of the five
2:17pipes as an opening of one inch giving
2:20the product a total opening of three
2:22point nine to seven square inches it’s
2:24important to note that the flow rate
2:25figure is arrived at with the pipe under
2:28ten pounds per square inch of pressure
2:30yet the multi flow pipe is not installed
2:33as a pressurized system this product is
2:36also intended to be installed level in
2:38order to have access to the cleanups
2:40flow rate is affected by the corrugation
2:42and lack of downhill slope unpressurized
2:45we assume the flow rate in reality is
2:48significantly lower than the published
2:50rate we sealed the multi flow drainage
2:53conduit in order to check holding
2:54capacity which is one-half liter the
2:58Minnesota uniform plumbing code gives
3:00officials the authority to allow other
3:02types of drainage conduit as long as
3:04they meet the minimum standard it
3:06appears the minimum standard is drainage
3:09conduit with an opening of 7.06 square
3:12inches a flow rate between 35 and 44
3:15gallons per minute and a holding
3:17capacity between one and one-half and
3:19one and three-quarters leaders in order
3:22to achieve these flow rate drainage
3:24conduit must be installed at a
3:26continuous downward slope while speaking
3:29with a manufacturer we were told
3:31drainage conduit installed level has a
3:33flow rate of zero to sum up it appears
3:37two of the four drainage conduits have
3:39significantly lower flow rates because
3:41of their smaller size and level
3:43installation which again yields a flow
3:46rate of zero as a result we believe
3:49those two products do not meet code and
3:51should not be allowed
3:57