Project Guide

How to Caulk Like a Professional

Prepare the Surface
person removing old caulk around bathroom sink with a utility knife

You can apply new caulk over old caulk, but it may not stick. A good caulking job starts with a clean surface.

  • Cut old caulk out with a utility knife or scraper. 
  • Remove all dirt, dust, grease and debris. If you’re removing silicone caulk, ensure all residue is completely removed. 
  • Use a rag to wipe the joint surface with rubbing alcohol or an over-the-counter disinfecting spray. Rinse thoroughly with water and dry.

Tip: If the gap you are caulking is greater than ½ inch, press a foam tape into the space.  

Tape the Area
person taping around bathroom sink

Apply painter’s tape to mask off areas around the joint where the caulk should not appear. This will give you a straight line of caulk and will improve the final appearance.

Cut the Nozzle
person cutting the tip off the nozzle of a caulk tube

A line of caulk is called a “bead”. The further up you cut the nozzle, the smaller the bead. Reversely, the further down you cut the nozzle, the wider your caulk line will be. 

  • Read the instructions on the caulk bottle for how to cut the nozzle. Some nozzles have a foil seal that will need to be punctured, and some nozzles also need to be removed to trim an inside seal. 
  • If using a squeeze tube, remove the cap and then trim the nozzle with scissors. 
  • For rigid plastic tubes, use a utility knife to cut the tip of the nozzle off at a 45-degree angle. 
Apply the Caulk
person applying new caulk around bathroom sink
  • If using a rigid plastic cartridge, place the cartridge in the caulking gun. 
  • Apply steady pressure to the trigger or tube and fill the gap with an even bead of caulk. 
  • It is best to push the caulk ahead of the nozzle to ensure that it gets into the joint for a proper seal.
Smooth It Out
How to Caulk - Person smoothing new caulk around bathroom sink

For a neat and professional-looking finish, “tool” or smooth the bead of caulk. Lightly drag a caulk finishing tool or putty knife over the bead to smooth it. 

  • If you used painter’s tape, remove the tape before the caulk “skins over” (meaning that the product has developed a firm skin on the surface, which normally occurs after a few hours). 
  • To correctly remove the tape, lift the edge up at a 45-degree angle away from you. 
  • Caulk usually dries in about 24 hours. Wipe away excess caulk with water and a damp cloth before the it dries. Excess dried caulk will need to be cut or scraped away. 

Tip: Some clear caulks will apply white and dry clear in seven to 14 days, depending on humidity and temperature. To reuse any remaining caulk on a future project, tightly reseal the cartridge and store within the manufacturer's recommended temperatures. 

Ready to find the supplies you need in your local store? Use The Home Depot app to locate products and check inventory. We'll take you to the exact aisle and bay. Need supplies today? Order before noon for convenient, scheduled same-day delivery,