I've removed an old toilet and macerator as we want to change the room back into a bedroom. Are the pipes just 15mm copper piping so just use normal blanking caps for them or do I need something else? Here's a photo:
You could cap it ,but that would leave a dead leg ,which may or may not be a problem. And of course you would have that unsightly section of pipework visible. Would be better to lift floorboards and remove that branch pipe totally.
The pipe goes down into the room below but then I can't trace where it goes from that. We are not working on the room below yet so I wasn't planning on taking up the floor in that room yet. Could I temporarily cap off under the floorboards in the room that was a bathroom and then remove the rest of the pipe in the room below at a later date?
Yes you can . I would solder a cap on ,as it is under a floorboard. But if you can't do it ,fit a compression ,as JP posted earlier, until you are ready to strip it out mate.