What is this pipe going straight into the ground?

Where is the other end going?

Could be water, doubt it's gas,but you never know.

 

Hold a thin stick against it and t'other in yer luggie, and see if it makes a hissing sound when a cold mains tap is turned on.

 

As Kiab has said, where does other end go?

May be discarded/disconnected...certainly very old looking at that compression joint. Be careful that there's not any old asbestos pipe lagging kicking around in the vicinity...you don't want to be disturbing that!

 

Wear a mask if you go mooching around the crawl space.

 

Where is your stop cock? What type of pipe feeds it? If its not incoming, are there any out buildings it could be feeding?

 

Thats a 'borrowers' escape tunnel!

 

Neighbors meter bypass!

 

In fact it could be gas, it's galvanised iron, rather similar to the disused old gas pipe, I just remember we have in cupboard here.

 

And compression was common practice in years gone. There was an old cooker feed to the upstairs hall here(pretty sure old owners had lodgers) and that was all compression.

 

Make tracing it the first priority, then work out from there. You don't want to be messing with it if its gas.

 

It most likely will rust and fail, if it's damp maybe it has already - be careful about disturbing it, could turn a problem into a crisis. Had a similar situation in my house, couldn't access the pipe, ended up running new plastic to bypass the connection to the pipe. When we got the old pipe out it fell apart, almost no metal left. We were pretty lucky to be able to get a connection onto the metal without it disintegrating.

 

It will de copper where the compression fitting is but could be wiped onto lead further on where you cannot see it.
If it was an iron/steel pipe it would not have a compression fitting on it as it would have a screwed thread and coupler.

 

Do you have a water meter fitted Matt? Sometimes they are fitted before the in house stop tap. If so, take readings with everything switched off before going to bed and see if there are any changes in the morning. May give an idea if you have a leak.

 

could be a water main or even what was known as town gas. how old is the property