Replacing a shower drain isn’t usually a difficult task, but it always pays to be prepared for complications before you start the job, especially as every project is different. While it should take just a couple of hours to replace a drain in a preformed shower base, you’ll want to allow yourself additional time and a flexible toolbox. “As the age of the shower increases, so does the likelihood of problems during installation,” says Daniel O’Brian, the technical expert for leading online plumbing retailer SupplyHouse.com. Over time, older metal drains can corrode, making them very difficult to remove, and you can even run into problems with installations in newer showers if access to the drain is restricted. No matter what challenges you face, the following tips will help the project go a little more easily. The majority of shower drainpipes are two inches in diameter, but if you have two-inch drains and you run into a three-inch drainpipe, you’ll be making another trip to the plumbing supply store. “Always check with local codes,” O’Brian suggests. “The larger drain size minimizes the chance of a shower overflowing.” And if you keep a supply of size-adaptable shower drains on h...