What is this damp band on wall?

[Blep]

The wall by my front door has a band of damp about 70cm above floor level. It feels wet to touch and is dripping down in places. It's a terraced house with a passage between mine and next door, so technically it is an outside wall, but it's not exposed to the rain so I'm not sure what's causing it?

Sounds like your damp course has failed. Get a damp specialist in for a look.

please post some photos. Show the entire wall, and the wet patch. Include something to show scale.

Inside and out please.

If it's actually dripping, it's more likely water from a leaking pipe or rain penetration, though it could be condensation. 70cm above floor is not likely to be water from the ground.

If you invite somebody into your home who sells chemical injections, they will advise you to buy chemical injections.

The few things you can be sure of with chemicals: they will not repair leaking pipes; or gutters; or puddles on paving lying against walls; or excess humidity leading to condensation.

@dampplug

you ought to start your own thread, as two different problems on the same thread will confuse the issue. In your new one, say how far above (or below) ground level it is.

Sorry!

Has the wall had damp treatment in the past?

A horizontal band like this is often associated with a poorly treated injection and internal render job. If the injecting wasn't carried out correctly, any dampness/salts can rise above the line of the waterproof render on the inside and create a damp tide mark (It's a common damp profile).

Check the ground levels in the passageway and see if there are any subfloor vents or leaks. The issue will be low down with the symptoms manifesting themselves higher up.