How to Clear a Clogged Drain and Prevent Future Clogs
Don’t use chemicals to clean a clogged drain. Use a plumbers snake and follow
  these tips to prevent future clogs.

 Clogged drains are the most common home plumbing problem, but you probably don’t think much about the    
  network of pipes inside your home’s walls until a drain stops working. Clogged drains are a hassle, but easily  cleared.

  However, you can avoid the hassle by paying attention to what goes down your drain. A little care prolongs the

 of plumbing pipes, prevents leaks, and avoids costly repairs.

  Avoid chemical drain-clearing products

  You can buy chemicals to clear clogged drains, but these products sometimes do more harm than good. They can    actually erode cast-iron drainpipes. And because they typically don’t remove the entire clog, the problem is likely    to recur, causing you to use the chemicals repeatedly. The caustic action of chemicals may eventually wear away    the insides of pipes, causing leaks.
 Better to hire a plumber to snake the drain (usually $85 to $325) and completely remove the chunk of hair or  grease that’s plugging the line.

 Better still (and cheaper!), pick up a manually operated augur, or snake, of your own, for about $15 at the  hardware store. Or, rent an electric snake for about $30 for a half day, and try clearing the clogged drain yourself.
  Prevent clogged drains
  Clogged drains aren't just nuisances. Backed up water puts added pressure on wastepipes, stressing them and    shortening their lifespan. To avoid clogged drains:
Keep food scraps out of kitchen drains. Scrape food into the trash before doing dishes—even if you have a disposal—and never put liquid grease down the drain; pour it into a sealable container to put in the garbage after it cools.

  •   Keep hair out of bathroom drains. Install screens over drains in showers and tubs, and pull out what hair you can 
  •   every few weeks to prevent buildups. 
  •  Keep anything but sewage and TP out of toilets.
  •   Keep your sewer lines or septic tank clear
  •   ​If you have municipal sewers, hire a plumber to snake your main sewage cleanout every  few years. This will cost   
  •   $135 to $600, and will remove tree roots that inevitably work  their way into these pipes leading to messy sewage    
  •    backups.
  •   If you have a septic system, get the tank pumped out every three to five years for $ 75 to $350; it'll be more larger  tanks.
  A former staff writer for the Wall Street Journal, Joe Bousquin writes about housing, construction, and home
    improvement. The galvanized steel water pipes in his 1930 home in Sacramento, Calif, have all been replaced  with copper.