Outdoor plumbing takes a beating all year round. From freezing winter temperatures to summer garden hose wear, components like outside taps, exposed pipework, and drain gullies are constantly vulnerable to weather damage.
A burst outdoor pipe or a split hose bib tap can cause sudden water loss, flooded gardens, and structural damp issues along external walls.
Whether you want to prepare your garden plumbing for winter or fix an active leak, here is a practical guide on how to protect and repair your external plumbing.
1. How to Protect External Plumbing from Freezing
UK winters regularly bring sub-zero spells that freeze water inside exposed pipes. When water freezes, it expands by around 9 percent, generating enough force to crack copper pipes, split plastic fittings, and burst tap bodies.
- Fit Thermal Pipe Lagging: Wrap all exposed outdoor pipes and loft supply lines in foam pipe insulation (lagging). Ensure the joints are sealed tightly with weatherproof tape to stop cold air reaching the metal.
- Install an Outdoor Tap Cover: Cover your garden bib tap with an insulated thermal tap jacket or polystyrene cover. These cost very little and shield the brass body from frost damage.
- Isolate Outside Taps for Winter: Most modern outside tap installations feature an internal isolation valve fitted inside the house (usually in the kitchen cupboard beneath the sink). In late autumn, turn this valve off, go outside, open the outdoor tap to drain out any remaining water, and leave it open. Without water trapped inside, the tap cannot freeze or split.
- Disconnect Garden Hoses: Never leave a hosepipe connected to your outdoor tap during cold weather. Water trapped inside the hose can freeze back into the tap body, causing severe internal damage to the mechanism.
2. How to Repair Common External Plumbing Issues
Fixing a Leaking Outside Tap
If water is dripping constantly from the spout or spraying from around the handle (gland nut), you usually do not need to replace the entire tap.
- Isolate the water: Turn off the internal isolation valve feeding the outside tap and open the tap to release water pressure.
- Fixing a dripping spout: Unscrew the valve body using an adjustable spanner, remove the internal spindle, and replace the worn rubber tap washer at the base.
- Fixing a leaking handle: If water leaks from the stem when the tap is on, gently tighten the small gland nut located directly behind the tap handle by a quarter turn. If it continues to leak, unscrew the nut and repacking it with PTFE tape before tightening it back up.
Fixing Split or Leaking External Waste Pipes
External plastic waste pipes (such as boiler condensate pipes or sink drain lines) can crack due to UV exposure or freezing weather.
- Clean and dry the damaged area thoroughly with a wire brush or cloth.
- For small cracks, apply self-fusing silicone repair tape tightly over the leak, extending past the split on both sides.
- For larger cracks, cut out the damaged section of pipe using a hacksaw and install a plastic pipe connector (coupler) secured with solvent weld cement.
Unblocking Outdoor Drain Gullies
Outdoor gullies gather leaves, moss, and garden debris, leading to standing water and unpleasant smells.
- Put on heavy-duty gloves and lift the gully grate.
- Clear out leaves, silt, and sludge manually into a bucket.
- Flush the drain with hot water and washing-up liquid, or use a drain rod to clear blockages further down the pipe run.
When to Call a Professional Plumber
While basic tap washer replacements and pipe lagging are simple DIY tasks, complex external plumbing work requires expert attention.
If you suspect an underground pipe burst (indicated by unexplained damp patches on brickwork, soggy lawn areas, or a sudden spike in your water meter reading), call a professional plumber immediately. Tracing underground leaks and replacing frozen main supply pipes requires specialized equipment to prevent long-term damage to your property’s foundations.
