Where do my overflow pipe lead to

Check from your boiler it may be your condensate pipe which get rid of condensation from flu gases from your boiler chance it could be off the bath but usually they are joined into the main waste but I wouldn’t rule that out I’ve seen it before.

Are the pipes dripping water ? Is the boiler near that area, as could be the condense pipe but it should be going to a drain in a larger pipe. Have you noticed this is more prominent in the last week or so? Check bath and shower seals by splashing all the seals And corners or spraying them with the shower head , do this for acouple minutes then have a look to see if the drip has increased , this might take up to an hour to soak through. Check pipes are not running back into the building incase they are disconnected inside and rain water is getting in , but very unlightly. ( if the Door is facing south West this is usually where the wind and rain hits us, but this weather is coming at us in all directions. If all in tanks in the attic have been remove and toilets got no overflow pipe (under neath the cistern you should see it inside) ( If theres a built in cistern that should over flow into the W/C. I think it could be a weathering problem over the door ( is the damp patch above the door head ) check all the flashing around that area.