Like painting, caulking is one of those home improvement projects that people like to feel that they already know how to do. In reality, most people simply have never learned the correct way to apply caulk, and more often than not, the job ends up being a mess. If you learn a few simple steps, though, your caulk jobs will look like they've been done by a pro.
Watch Now: How to Caulk Like a Pro
Equipment / Tools
- Caulk gun
- Retractable razor blade scraper
- Shop vacuum
- Rubbing alcohol
- Cotton rags
- Blue painter's tape
Choose the Right Caulk and Dispenser
The first step is to evaluate your project and choose the proper caulk for the job. There are a number of different caulks, colors, and dispensing methods from which to choose.
Caulk typically comes in three varieties: latex, silicone, and butyl rubber.
- For dry areas, vinyl latex caulk works best.
- For wet areas, the nod goes to silicone caulk.
- For exterior jobs, butyl rubber works great.
- For interior home repair caulking projects, use either a latex caulk or silicone caulk.
The type of caulk gun or dispensing tool you use is also an important decision. Caulks can be purchased in either squeeze tubes or in cartridges that are loaded into a caulk gun. The pros typically use cartridges and a smooth-action caulk gun, both to save money and achieve the best results.
Remove Old Caulk and Clean the Surface
Removing the old caulk (as needed) and preparing the surfaces is very important for an effective caulk application and repair. To prep the surfaces, remove the old caulk with a retractable razor blade scraper. For caulk joints in corners, such as where wall tile meets a tub, sink, or countertop, a caulk removal tool works great. Use a shop vacuum to remove all debris from the joint and the surrounding area. Finally, clean the surfaces with a rag and rubbing alcohol.
Tape off the Surfaces
Apply strips of blue painter's tape to mask off both surfaces at the point where you want the edge of the caulk bead to stop. Make sure the tape is straight, and use long sections of tape, not short pieces. The joint will look best if you tape to create a fairly thin joint, about 1/4 inch in total width.
Press down firmly along the inner edges of the tape. The goal is to seal these edges so caulk cannot seep beneath it. This can be done with your fingernail to ensure a tight seal, or with a wooden popsicle or craft stick.
Apply the Caulk
Open the caulk tube by cutting the tip of the nozzle at a 45-degree angle, using a utility knife, then insert a long, clean nail or wire into the nozzle to puncture the inner seal. Poke through the seal a few times to ensure a smooth flow of caulk. Some caulk guns have a built-in snipper to clip the tip of the caulk tube, as well as a puncture wire to break the seal.
Apply the caulk at a 45-degree angle between horizontal and perpendicular. Make sure to squeeze hard enough to force the caulk fully into the joint.
Draw the tip of the caulk tube along the length of the joint as you slowly squeeze the handle of the caulk gun, working at a speed that is slow and consistent. The smoother the initial application, the better the end results will be.
Cut the nozzle closer to the tip for a narrower caulk bead or farther down (toward the tube) for a wider bead.
Smooth the Joint
Wet your finger with either rubbing alcohol (for silicone caulk) or water (for latex caulk). Also, dampen a corner of a cloth rag with either water or alcohol, as appropriate. The alcohol or water will serve as a lubricant and thinning agent as you smooth the joint.
Using light pressure, smooth the caulk joint, working from one end to the other. As your finger becomes laden with excess caulk, wipe it off with the dampened rag and re-wet your finger. Continue the smoothing process until the entire taped section you're working on is finished.
If you dislike the idea of getting caulk on your fingers, you can use a rounded craft stick (popsicle stick) instead of your finger, or wear a tight-fitting latex glove.
Remove the Tape
Immediately remove the blue painter's tape used to mask the joint. Remove the tape away slowly, and pull it away from the joint at an angle, not toward the joint. Let the caulk cure fully, as directed by the manufacturer, before getting it wet or painting it.