FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Fine Homebuilding Project Guides

Tiling

Guide Home
  • Selecting Tile
  • Tools & Techniques
  • Installation Materials
  • Preparation
  • Tiling Floors
  • Tiling Walls & Backsplashes
  • Tiling Showers
  • Grouting, Sealing & Caulking
  • Maintenance & Repair
How-To

Silicone Caulking Basics

For caulking around bathroom and kitchen fixtures or ceramic tile, nothing lasts longer or keeps out moisture better than silicone.

By Brian Zavitz Issue 111
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Synopsis: It’s not hard to make a mess with a tube of silicone caulk and a caulk gun — plenty of us do. This article, written by an experienced renovation contractor, explains how to apply this material so it goes where you want it to. Tips cover the simple tools used to shape a bead of caulk once it’s in place.

Sealing a bathroom fixture, kitchen fixture or ceramic tiles with silicone caulk is one of those small details that — done well — raises a job above an ordinary level. I don’t know how many times I’ve seen the effect of a good tiling job — and sometimes even a superior one — spoiled by sloppy caulking.

Proper silicone caulking accomplishes two things. It prevents water from finding its way into the gaps where two surfaces meet, with enough flexibility to maintain the integrity of the seal even if the materials shift a bit over time. And when the caulk is smooth and even, it helps to prevent the accumulation of dirt and mildew outside the seal, which helps to maintain the aesthetics of the job over time. A workmanlike job accomplishes the first purpose, but it requires more practice and care to accomplish the second.

Silicone caulk is the caulking of choice for ceramic tile, showers, tubs, sinks and other bathroom and kitchen fixtures. It costs more than latex caulk, but it lasts longer — up to 20 years. It’s a rubbery material with a tenacious grip, so it does a better job of stretching and flexing. Because it stretches without cracking or splitting, it does a better job than latex of sealing out water that inevitably accumulates next to kitchen and bath fixtures. Also, it has a wide temperature-application range and can withstand temperatures from below 0°F to about 400°F.

The drawbacks include silicone caulk’s finicky nature when it’s being tooled and its reluctance to adhere to painted surfaces, plastics or oily woods. Also, silicone caulking is generally not paintable.

Start with the right stuff

The basic caulking tool is, of course, a caulking gun, but even here a little care is needed. A gun that operates with ratchet action is no good for fine work. With ratchet action, you have to release the trigger and reach around to the back, grab the end of the rod and twist it to relieve pressure in the tube. In that time, it’s easy for excess material to squeeze out, and the action can cause the tip to jerk, which spoils the bead.

Instead, find the type with a (usually) hexagonal rod and no notches, which is released by pressing your thumb on a tab behind the handle. This type of caulk gun delivers caulk with a smoother flow, and the pressure can be released instantly so that you won’t have to take your eyes or your hands away from the work. (Tub and tile caulk in a squeeze tube works only on very small jobs. There’s just not enough caulk there to give a long and consistent bead.) Some caulk guns have a spout cutter that is incorporated in the handle, but I prefer to cut the spout cleanly with a sharp knife.

All silicone is not the same, either. Some caulks are firmer than others coming out of the tube, and some skin over faster. Some are more flexible when cured or come in more colors. GE’s silicone, the granddaddy of them all, is still among the best. I find it easy to work, strong and flexible, and I like the opaqueness of its white. I also find that the white yellows a bit, so when working with pure-white tiles, I prefer to use an-other brand, such as Hilti. Whatever brand you choose, always get the type specifically made for tub and tile work, which contains compounds to inhibit mildew.

 

Choosing a color when the job calls for some-thing other than white can be tricky. Almond (or bone) and gray are the most common variations, but manufacturers offer widely differing renditions of those colors. If a close match is important, I often buy tubes of a few different brands, then squeeze out test beads on site to make a final choice. Usually, an exact match is impossible, in which case I prefer a color slightly darker than the material I’m applying it to.

One expedient is using clear silicone, but that’s a last resort for me for two reasons. First, if there’s a fair-size gap at the joint, it remains visible after the caulking is done. Also, after tooling clear caulk, I may not be able to see some smears or excess, but they sure will show up once the bead gets dirty. Nevertheless, for some jobs, particularly against wood trim or where you have materials of different colors meeting,clear may be the best solution.

caulking tools
The basic tools are pretty basic. A decent caulking gun—the type with a hexagonal rod and thumb-tab release—a spoon, a utility knife, a scraper, a brush and cleaners are all you need to do a first-rate caulking job. Also bring along plenty of paper towels for cleaning up.

get rid of old caulk
Get rid of the old caulk first. A good, flexible utility knife, such as this one that has break-off blades, can reach down behind the old caulk to cut it loose from the surface. Remember to take care when cutting near a fixture that’s made of fiberglass or another soft material.

caulking from the corner
Start the bead at an inside corner. By starting at each corner and overlapping in the middle, you can keep a watchful eye on the bead as it comes out of the caulk gun and carefully control the pressure on the bead.

Prepare the area to be caulked— Proper preparation of the area to be caulked is especially important with silicone. Even with a brand-new installation, I make sure the surfaces are clear of dirt, excess glue or silty deposits of grout. When remodeling, the big enemies are soap, scale and mildew.

If I’m recaulking, I start by cutting out all the existing silicone with a utility knife, then scraping the surface clean with one of those paint scrapers that hold a single-edge razor. Next I scrub the whole area with a bit of wood alcohol. It does a good job of dissolving soap deposits, and it’s also the least toxic thing I know of that will dissolve uncured silicone(nothing I know of dissolves cured silicone). This comes in handy later if I need to clean up stray silicone. If the area to be caulked is really scaly or particularly disgusting, I’ll scrub it with a weak solution of muriatic acid or trisodiumphosphate (TSP).

If there is still some mildew remaining in the grout, I may wash it with bleach or even rake out the grout and redo it. After making sure that the whole area is clean and dry and that any traces of the wood alcohol have evaporated, I’m ready to start. Before cutting the tip of the caulking tube, though, I always have a plentiful sup-ply of paper towels close at hand. Silicone caulking can be pretty messy.

Start with the smallest-possible bead— I cut the tip of the tube spout on an angle, as close to the end as practicable for the job. It’s all too easy to get too much caulk on the work, and all too hard to get rid of it neatly if you do. So I work with the absolute smallest bead that will fill the gap. Silicone-caulking manufacturers say there is no minimum-size bead, although they don’t recommend beads that are more than in. wide. That’s because the bigger the bead,the longer it takes to cure. However, if time isn’t a problem, a larger bead won’t be a problem.

I always start at an inside corner. If there is an inside comer at each end of a joint, then I work out from both, overlap-ping the two beads somewhere in the middle. Otherwise, if I caulk continuously from one in-side corner to the next, I end up obstructing my own view of the bead and risk putting a kink in the bead at the point where I turn the gun to-ward the other corner.

If there is a three-legged joint, such as where two tub-enclosure walls meet the tub, I do the vertical joint first. I keep the caulk flowing smoothly out under the angled tip and am careful not to let it squeeze out from either side. It takes some practice to lay down along, even bead, especially to be able to slowdown just enough to compensate for the reduced flow when releasing the trigger to start another stroke.

Some manufacturers recommend pushing the gun away from you as you lay down caulk, but I like to pull the gun away from the bead. Pushing the gun won’t squeeze the caulk down into agap as well as having the long angled tip bearing against the bead as you move along. Also, pushing the gun obscures the bead, which makes it impossible to control its size and position.

 

control the flow
Learn to control the flow. It’s critical to the job to keep the caulk flowing smoothly and not to let it squeeze out from either side. With practice, anyone can lay along, even bead.

use finger to smooth silicone caulk
Finger-licking smooth. Usually, a firm, even swipe of the finger gives just the right convex shape to a caulk joint. The author’s preferred lubricant for his finger is saliva, but he’s careful to wipe off his finger before putting it back in his mouth.

The best bead tool is always within reach— I almost always tool each bead immediately after applying it before I move to the next joint. This way, I’m sure I get to the material be-fore it skins over. Also, if I have to add a bit more on top somewhere, I want to do this while it’s in its most workable state.

Like a lot of people, I find that the most useful tool for dressing joints is a finger, which can adapt itself to the small variations in the surface or size of the joint. If I’ve put down a bead that is no larger than necessary, one firm swipe with my finger usually gives a nice convex shape to the joint and adheres it firmly to the surfaces on both sides of the gap or angle.

Small irregularities in the caulk will trap dirt and harbor mildew, making for unsightly problems later on. For this reason, I take more care than would be needed just to ensure a water-tight joint. Most times, I wet my finger with saliva and go over the joint again, polishing it and eliminating tiny irregularities. I’ve tried wetting my finger with water, but saliva seems to work best. I’m careful not to wet the ends of a bead where the next bead needs to adhere to it.

I talked to several manufacturers of silicone caulk, none of whom recommend a licked finger to tool their caulk. All agree, however, that the licked finger is in widespread use and that there is no major health risk involved. They also say it’s not a good idea to allow silicone to stay on the skin. They recommend using a spoon dipped in soapy water or smeared with petroleum jelly. I haven’t had a problem doing it my way, though. But silicone isn’t particularly tasty,so I keep paper towels or newspapers handy to clean my finger.

Sometimes, usually when a joint is wider than my finger can bridge properly, I need a different tool. I keep an old cereal spoon with a fairly tight radius on the tip just for this purpose. Turning the spoon at various angles, I can create just about any type of cross section I need.

I find that the spoon works best used in a scooping position instead of with its rounded back pressed into the bead. When tooling with the spoon, I do a dry run along the joint before applying the caulk, testing for the proper angle to achieve the bead I want.

use a spoon for tight spots to smooth silicone caulking
A spoon can get into a tight spot. A spoon that has a fairly tight radius on the tip can create just about any type of cross section, even a wide joint such as the one around this glass-block window.Sometimes it’s necessary to mask around the bead with tape.

replace silicone caulk gun tip
Put the tip back where it came from. After you snip the tip of the caulk nozzle, save the little cone of plastic. When you’re ready to seal the tube, squeeze a little caulking out the tip and press the inverted tip back into the hole for a snug fit.

Finishing up and putting away the caulk— When I’m tooling a wider joint using the spoon—a joint that’s in. wide or more—it’s often impossible not to have some caulk squeeze out on both sides of the tool. I don’t worry about this.The hard edges of the spoon create a definite edge to the joint and scrape a clean track right beside it. If I go back an hour or two later, when the caulk has just firmed up, I can scrape away the excess.

I rarely mask both sides of a joint with tape; I don’t like to because the edge of the bead can-not feather down to absolutely nothing due to the thickness of the masking tape.

I’ve heard many tips about how to close spouts of partially used tubes of caulking, but generally they don’t help for long. Any seal has to be air-tight. Some manufacturers help by supplying snap-on caps for spouts, but even this solution doesn’t work if you’ve had to cut the spout short to get a wide bead. I save the tip I cut off when I started the tube. Inverting this into the opening and holding it in place with a bit of caulk squeezed out around the edges works better than anything else I’ve tried.

From Fine Homebuilding #111

For more photos and details, click the View PDF button below:

Fine Homebuilding Recommended Products

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

Anchor Bolt Marker

Quickly transfer anchor bolt locations to mud sill stock without measuring mistakes.
Buy at Amazon

Smart String Line

String lines — sometimes called dry lines — are invaluable for straightening walls and a million other things. The reel makes it easy to stretch and wind the string.
Buy at Amazon

100-ft. Tape Measure

Laying out mudsills and foundations for new homes and additions requires a bigger tape measure than your everyday carry.
Buy at Amazon
View PDF
Previous: Applying Caulk Next: Expansion Joints in Tile Floors

Guide

Tiling

Chapter

Grouting, Sealing & Caulking

Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Tiling

Tiling

Trusted, comprehensive guidance from the pros for a great-looking tile job in any room of the house

View Project Guide

View All Project Guides »

Become a member and get unlimited site access, including the Tiling Project Guide.

Start Free Trial

Selecting Tile
  • The Basics
  • Tile Options
Tools & Techniques
  • Job-Preparation Tools
  • Cutting Tiles
  • Setting & Grouting Tools
Installation Materials
  • Membranes & Substrates
  • Adhesives & Mortars
  • Grout
  • Sealers & Caulk
  • Spacers, Hardware & Trim
Preparation
  • The Prep Job
  • Repairs & Surface Prep
  • Installing Backerboard
Tiling Floors
  • Layout & Installation
  • Setting Specialty Tiles
Tiling Walls & Backsplashes
  • Preparation
  • Backsplashes
  • Walls
Tiling Showers
  • Tile Shower Basics
  • Waterproofing
  • Shower Pans
  • Shower Drains
  • Shower Niches
  • Video Series: Tile a Shower
  • Video Series: Tile a Barrier-Free Bathroom
Grouting, Sealing & Caulking
  • Grouting
  • Caulking
  • Sealing
Maintenance & Repair
  • Maintenance
  • Tile Repair
  • Grout Repair

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 81%

Subscribe

This is your last free article.

Don't miss another expert tip or technique from building pros. Start your free trial today.

Start your FREE trial

Already a member? Log in

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data