Do all the wastes go into one external vertical pipe? A soil stack. This should be open or vented at the top or the rush of water from your Loo can suck air through a bath/shower/sink U-Bend.
Yep that's right. There is a vent on the top of the stack. We had a loft conversion done about a year ago, but this gurgling has just started within the past couple of weeks.
We can all use the outside toilet, it's pretty refreshing at this time of year
Do all the wastes go into one external vertical pipe? A soil stack. This should be open or vented at the top or the rush of water from your Loo can suck air through a bath/shower/sink U-Bend.