I have 2 seperate showers (upstairs) both have slow drainage whats the best way to clear it

The reason for your drain blocking is not due to using chemicals, it is more likely that it is blocked up. If the showers drain slowly then I would imagine that the waste pipe or trap are getting gunged up and need cleaning/replacing. Another reason might be is that waste pipe is running slightly uphill. I would suggest that you tun shower and if shower tray is filling up or emptying slowly, I would first clean Shower Trap out and test, then if same replace Waste Pipe. Bill Pipe Dreams Plumbing Services

Hi, dont waste any more money on drain unblockers. the only way to fix this is get a plumber in and check it out, it will cost a bit but only way is to make sure you a good fall on waste and to clear any blockage, best wishes rigsby.