The distance between the gutter and the wall
is bridged by an offset. This consists of two 67.5º
(112º) Offset bends and an appropriate off cut of downpipe
cut to size (7),
(with 65mm square downpipe, a ready- made 50mm offset is available). The offset bends can be push-fit or solvent-weld; if push-fit, ensure a pipe clip is fitted under the socket on the pipe immediately below the offset. When using solvent cement, follow the safety instructions on the tube.
To keep the cut square, wrap a piece of plain paper round the downpipe at the place to be cut, and use this as a guide for a hacksaw. Clean up the cut edges with a file.
Fit the first length of downpipe with its socket uppermost, securing it to the wall with a socket pipe clip at the top (8) and one-piece barrel clips (where available) for holding the pipe to the wall. For masonry walls, use an electric drill fitted with an appropriate bit to make holes to take rawlplugs for the securing wall screws. The maximum spacing of pipe clips is 1.8m (6ft).
Continue to fit the remainder of the pipe in the same way, fitting the open end of one pipe into the socket of the pipe below, allowing a 10mm gap between the end of the pipe and the bottom of the socket for expansion in warm weather.
Some downpipes are fitted with a hopper head to receive waste from another pipe. Secure the hopper head to the wall. Adaptors are available for square downpipes.
If necessary, the downpipe can be run at an angle across the wall, using pairs of 45º, 67.5º or 87.5º bends. On angled or near-horizontal runs, fit pipe clips every 1m (3ft).
Where the downpipe from a second gutter (around a bay, for example) joins the main downpipe, use a 67.5º branch pipe. If you need to cut both ends of a pipe, fit a loose pipe socket (available with wall-fixing lugs for 65mm square pipe) to the end of the pipe.
With 65mm square and 68mm circular downpipe, you can fit an access branch into the downpipe. This makes future downpipe cleaning easier.
At the bottom of the downpipe, fit a downpipe shoe if the
water is to discharge onto a flat surface or into an open
gully (9). Downpipe shoes on round pipe need supporting
with pipe clips.
For direct connection to the underground drainage, ensure that you have the correct connector (or adaptor for 65mm square pipe); to connect to a back inlet gully, remove the old mortar and replace with fresh mortar with the pipe in place.