Outside taps and frost: why the inside valve matters

An outside tap is one of the simplest things a plumber fits, and one of the most common to split in a cold snap. The difference is nearly always one small part: an isolating valve on the inside of the house.

Why outside taps split

Water expands when it freezes. A tap and a short length of pipe on an outside wall hold just enough water to crack a fitting when the temperature drops overnight. You often do not notice until it thaws and the leak starts, sometimes inside the wall.

Homes on exposed spots, whether up the valleys or close to the sea in Porthcawl, take the worst of the wind, so the risk is higher there.

How it should be fitted

We fit outside taps with:

• An isolating valve inside the house, on the pipe feeding the tap, so you can shut it off from the warm side of the wall.
• A drain point, so once the valve is off, the water left in the pipe and tap can be let out.
• A short, well clipped run through the wall, sloping so it drains.

With that in place, draining down before winter takes a minute.

Draining it down

1. Turn off the isolating valve inside.
2. Open the outside tap and leave it open.
3. Let any trapped water out of the drain point if there is one.
4. Disconnect the hose, which holds water too.

Turn it back on in spring and check for drips the first time you use it.

If yours has no inside valve

You can lag the tap, but lagging only slows the cold down. The proper fix is to add an isolating valve inside, and it is a short job. If you are having any other plumbing done, it is worth adding at the same time.

Getting an outside tap fitted

Outside taps are everyday work for us across Bridgend county, including Porthcawl. Send a photo of where you want it, inside and out, and we will price it before we start. Price my outside tap.