Most downspouts are not a standard size, so a standard adapter leaves gaps and bottlenecks. Here is why we build a custom adapter for a clean tie-in.
We built a custom adapter, vented under the pavers, and cut through to tie a downspout into a 6-inch line. How downspouts and pavers work together.
One of the worst connections we have seen: a downspout necked down to tiny pipe with a channel drain piled on. Here is why pipe size decides everything.