Downpipe repairs

Summary: Learn how to unblock a downpipe, remove a UPVC downpipe, remove a cast-iron downpipe and prevent a blockage in the downpipe.

When repairing a downpipe, always use a ladder with stand-off brackets or arrange for a helper to support the bottom of the ladder.

Unblocking a downpipe

If the guttering is overflowing, the cause is most likely a blockage in the downpipe or in the swan-necked section at the top of the downpipe. Blockages can be caused by a bird’s nest, a ball or a collection of wet leaves. Another indicator of a blocked downpipe is water leaking from a joint where two sections of downpipe are joined together. This also indicates which section is blocked: it is in the section directly below the leaking join

  • Block the bottom of the downpipe with a rag to prevent the debris going down the drain.
  • From the top of the ladder use a length of wire to loosen blockages near the top, hooking out the obstruction if possible.
  • If the blockage is further down the pipe use a flexible drain rod to probe the downpipe.
  • To ensure all the debris has be cleared away return to the top of the downpipe with a hosepipe and flush any remaining debris down the pipe.
  • Remove the rag from the bottom of the downpipe and dispose of the loosened debris.
  • If you cannot loosen the blockage with a flexible drain rod, you will need to remove the downpipe in sections to gain access to the blockage.
Starting from the bottom of the downpipe, remove the pipe nails fixing the integral lugs to the wall.

Removing UPVC downpipes

  • Starting from the bottom of the downpipe, remove the screws securing the pipe clips to the wall. If your downpipe is secured to the wall by two-part brackets, undo the bolts holding the rings to the back plates but leave the back plates fixed to the wall.
  • Work your way up the wall removing sections of pipe until you reach the section with the blockage.
  • Probe the blocked section with a flexible drain rod to clear the blockage.
  • When the blockage has been cleared, the pipe sections can be fixed back in position.

Removing cast-iron downpipes

  • Starting from the bottom of the downpipe, use pliers to remove the pipe nails fixing the integral lugs to the wall.
  • Prise rusted lugs away from the wall using a claw hammer and cold chisel.
  • Carefully remove the section of pipe from the wall and probe it with a flexible drain rod.
  • Work your way up the wall, removing lugs and pulling sections of pipe gently away from the wall until the blockage has been located and cleared.
  • When the blockage has been cleared, re-fix the pipe sections to the wall.

Preventing blockages

To prevent future problems with a blocked downpipe, wire or plastic downpipe covers in various sizes are available, which can be fitted over the opening at the top of the downpipe.

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