What is This?

stuart45

BankMum said:

Hi Stuart, what sort of flue? It's away from the house.
There is no septic tank at the property and we can't find a manhole.

It's for a chimney flue. If you dig down a couple of inches you'll see the bottom of it. You should get £20 for it on eBay.

JuzaMum

You could test if anything is venting gases into it by putting a bag over, squeezing the air out and taping it on below the holes. If it fill up with gas, you'll see in inflated.

stuart45

A drain shouldn't be vented with sewer gases exiting at ground level. The older ones had vents with a mica valve that allowed air into the system when needed, but nothing out.
An SVP has to terminate above the eaves. 

jonnydeppiwish!

FreeBear said:

Is it wrapped in a Tesco Bag for Life ?

Brilliant, forgotten all about that post!

Section62

JuzaMum said:

You could test if anything is venting gases into it by putting a bag over, squeezing the air out and taping it on below the holes. If it fill up with gas, you'll see in inflated.

This would only work if the system operated at a higher pressure than atmospheric and had no other ventilation.  With drains there is normally another source of ventilation, and in the case of septic tanks the breather is (usually) there to allow air in rather than to vent gases out (as per stuart45's comment).

If the OP's mysterious pipe were a drain vent then putting a plastic bag over it probably wouldn't have any effect at all as any gases produced by the sewage would vent elsewhere.

Generally it isn't a good idea to cover 'vents' if you don't know what they are - although probably unlikely in the OP's case, if the vent were allowing air into a room or space with an open combustion appliance there is a risk of build up of CO with potentially deadly consequences.  If someone isn't sure what a vent does it needs to be explored using physical/visual methods - for example by sticking a borescope-type camera into it.  In the OP's case though I think the question would be answered by carefully removing soil around the base until the bottom is found and confirmed not to be connected to anything.

twopenny

Just to confirm

https://www.jjroofingsupplies.co.uk/flue-vent-190mm/?gad_source=1&gclid=EAIaIQobChMI2YXD64LOiwMVrJlQBh3CpxwxEAQYASABEgJuPPD_BwE

You could sit a gnome on it and pretend it's a mushroom.

Or a rocking plant pot.