How to winterise an outside tap
Outside taps are a common casualty of the British winter. When temperatures drop below freezing, water trapped in the exposed pipework can expand and crack the copper or plastic pipes running through your walls — and that damage often goes unnoticed until spring when you spot water stains or damp patches inside. It's a problem that catches thousands of homeowners out every year, particularly those in Scotland, Northern England, and rural areas where winters are harsh. The good news is that winterising your outside tap takes less than ten minutes and costs almost nothing. This guide walks you through the proper process, from isolating the water supply to protecting the tap itself. If you're uncomfortable working with isolation valves or suspect your pipes may already be damaged, it's worth calling a Gas Safe registered plumber to check things over before the cold season arrives.
Not sure if this matches your problem?
Use our interactive tool — answer a few questions and get a personalised diagnosis.
Most likely cause & what to check
Outside taps in the UK are vulnerable to freezing between November and March. A frozen outside tap can burst the pipe inside the wall, causing significant internal damage.
Locate the inside isolation valve for the outside tap — usually a small lever valve on the supply pipe inside the house (under the kitchen sink, or in the garage/utility room). Turn it off.
Go outside and open the outside tap fully to drain any water remaining in the pipe between the isolation valve and the tap.
Leave the outside tap in the open position — any residual water that does freeze will have room to expand without bursting the pipe.
For extra protection, fit a foam outside tap cover (£3–£10 from any DIY store) over the tap.
Reconnect in spring: close the outside tap first, then slowly open the inside isolation valve. Check for any leaks before using.
Prefer to have it done for you?
Find me an engineer →🛠 Tools & materials you may need
Was this guide helpful?
Frequently asked questions
What happens if an outside tap freezes and bursts?
A burst pipe inside the wall can leak water into your cavity, loft space, or internal walls, leading to damp, mould, and structural damage that's expensive to repair. You may not notice the problem until spring when water damage becomes visible — by which point the repair bill can run into hundreds or thousands of pounds.
Do I need to turn off the main water supply to winterise an outside tap?
No — you only need to close the isolation valve for that particular tap, which is usually located under the sink or in the utility room. Turning off the entire main supply is unnecessary and would stop water to the rest of your home.
Can I just leave the outside tap closed for winter without draining it?
Leaving it closed without draining is risky because water trapped between the isolation valve and the closed tap will still freeze and expand, potentially cracking the pipework. You must open the tap fully after isolating the supply to let any remaining water drain away.
When should I reconnect my outside tap in spring?
Wait until the risk of hard frosts has passed — usually mid-April in most of the UK, though this varies by region. Close the tap first, then slowly open the isolation valve indoors and check for any leaks before using it.
What if my outside tap doesn't have an inside isolation valve?
Older properties sometimes lack one, which means you'll need to isolate at the main stopcock instead. Consider having a qualified plumber install a dedicated isolation valve — it's a small job that makes future winterisation much simpler and safer.
Is a foam tap cover enough on its own?
A foam cover helps, but it's only effective if the pipe itself has been drained first. The cover slows heat loss but won't prevent freezing if standing water remains in the pipework — always drain the tap as the priority step.