10 things you must know about installing a bathroom vanity
You can go from a pedestal sink to a vanity, but if you're going from a vanity to a pedestal sink, you're going to probably have to redo plumbing within the wall. You may have to call a plumber to adjust the rough plumbing.
Sometimes the simplest things get overlooked. Remember to turn off your water valves underneath the sink before you start anything. There will always be water in the trap, so get a bucket to catch that residual water. Experts recommend using a pasta pot with this. It is the perfect size to fit under the trap.
Make sure you cut through any silicone caulk before you attempt to remove your vanity. Use a drywall knife or a putty knife to cut through the caulk. Disconnect the top of the vanity from the wall instead of tugging at it.
Take into consideration your piping arrangements before purchasing your vanity. If the vanity has drawers, make sure you clear your plumbing. If your pipes have to be rearranged, you are going to have to hire a plumber to do the work.
Most bathrooms don't come with the luxury of a lot of space. When you're installing a new vanity, save yourself uncomfortable work and install the faucet before you install the vanity. This will save you a lot of trouble underneath the sink once it's connected to the wall.
Level and Plumb
Make sure your vanity is level and plumb before fastening it to the wall. If it's not level, shim the bottom of it with small wooden shims. If you have multiple cabinets, make leveling easier by screwing them together.
Finding your studs before the installation will prevent loads of trouble (like drilling a screw in your water or electrical lines). You can use a stud finder and mark it by penetrating a small nail to the stud. If you're replacing an old vanity, be conscious of where the old screws were. Most likely they were drilled into the studs.
Replacing the Lines
Soap, toothpaste, hair dye and other things that go down drains produce acid and chemicals that corrode and deteriorate your trap. If you're replacing the vanity, take the opportunity to replace your plumbing lines. It's easier to install new connections than old ones.
Pipes will move and expand. Cut the hole in the back of your vanity a quarter inch larger than the pipe to prevent cracking, bumping and noises. Besides avoiding noisy plumbing, you want to leave room for installation, as shimming will probably be taking place for a perfect fit.
Testing the Drains
Open your valves back up after installation one at a time, slowly letting in a little bit of water. This will test your drains and make sure you have no leaks. If you do find a small leak, you can use Teflon tape right on the threads, or tighten up the valves a little more. Make sure you don't tighten them too much. Just get them snug. It's the seal that stops the leak, not the tightness.
1. Remove the doors and drawers from the vanity when installing. This will remove any risk of damaging the doors or drawers when you are installing the unit.
2. The best way to cut off the extra from the shims is to score them with a utility knife. Then, fold it up and back down to break it off. This will provide a clean break so you won't have to worry about damaging the cabinets by using a hammer and chisel.
3. Always measure the area of where you want to install the vanity before purchasing the unit. With the old vanity removed, you can even draw out on the wall with a pencil the dimensions of your desired vanity. This will ensure you have adequate space and the right unit for your bathroom.
4. When removing the old vanity, watch out for clips. If your clips don't come off easily, break them off, but be careful not to break the sink. The sink is much easier to take off in once piece than small, broken pieces on the floor.