Caulk is a necessary tool in any DIY-ers arsenal! I’m here to break down why, the kind you need for which project, and how in the world to get that perfect caulk line.
You’ve probably heard us say that caulk is the glue that holds an old house together. If you’re a home lover too (which, of course you are!), I’m sure you’ve even seen us or any other DIY blogger time-lapse the caulking of many baseboards and accent walls. It’s so, so satisfying to run that bead of sealant across a small gap and close it up in an instant – who’s with me? But today, I wanted to break down how to use it properly for the best results, because although we’re always talking about it, I think we tend to gloss over the basic fundamentals. And since it’s one of my all-time favorite tools in my DIY arsenal, let’s change that!
When to use latex vs. silicone
The main difference is: Latex caulk (or sealant) is paintable, whereas silicone caulk is not. Think: Latex caulk needs latex paint.
- Latex caulk is the preferred choice for gaps along baseboards, door casings and wall treatments (such as board and batten). Once applied, latex caulk can and should be painted with latex paint.
- Silicone caulk is the preferred choice for a water tight seal around bathtubs, sinks and countertops. It comes in a handful of colors to best match your need, since it cannot be painted. For example, white caulk along the back of a white sink and around a white tub.
Choose a premium product. It’s worth the extra dollar!
We’ve skimped on caulk (or sealants) in the past and have regretted it immensely. It’s worth the extra dollar to ‘invest’ in a caulk that has better flexing power, especially if you live in colder climates, as your millwork is incrementally shrinking and expanding throughout the seasons. If you use bargain caulk, you may notice that your perfect line has already begun to crack after its first winter. Been there, done that. Never again, no thank you!
We have a big stack of sealant at-the-ready in our workshop for various household projects. I recommend have 2-3 tubes on hand at all times, so that you’re never running to the store at the last minute! The brands that we’ve had the most success with and would purchase over and over again are:
It’s best to gather all your supplies before you begin, so that you’re not rushing to find a tool while the caulk begins to dry! These are the key ingredients to your perfect caulk line:
- Tube of caulk
- Dripless caulk gun
- Cup of water
- Paper towels (optional)
- Painter’s tape (for silicone caulk)
- 3/8″ – 1/2″ Backer rod*
- A good podcast or playlist to get you through!
If you’re starting with a fresh tube, you’ll need to snip off the top before loading it into your gun. Some caulk guns have a snipper built right in (you’ll find it by the handle if it’s there), but we still prefer to use a pair of utility snippers like this. Cut the tip at a 45-degree angle, enough to allow for a 1/4″ bead. Anymore more and your lines will be unwieldy, anything less and you’ll struggle to get the product out of the tube!
* If you have a gap to fill that is larger than 1/4″, it can be difficult to get sealant into the crack, since there is nothing for it to adhere to. This is where baker rod comes in! It’s thin foam tubing that you can push into the gap, giving the caulk a place to rest.
Apply, Smooth, Repeat
With your playlist in full swing, it’s time to caulk! I like to work in 6′-ish sections, which allows me to run a bead, smooth and repeat on the next section before the caulk has set. If using latex caulk, I dive right in. With gentle pressure on the cartridge handle, I run my first line while keeping the gun moving. That’s the important part – never allow the gun to stop moving!
Then I dip my finger in water (you may want to use gloves) and run it along the bead. The water prevents the caulk from sticking to my finger, while also nicely smoothing the line. If your swipe didn’t go as smoothly as planned, re-dip your finger in water and smooth again. I find that you can never have too much water! If there’s any excess on my hands, I wipe it onto a wet paper towel before moving on.
Which Surface Should You Paint First?
If you’re using latex caulk, once it’s dried (typically around 1 hour for the brands I’ve mentioned above, but always read the instructions for dry times), it’s time to paint! Because the latex caulk is touching both the wall and the trim, you’ll want to apply both paint colors. My general rule of thumb is to over-brush any millwork first, and then I cut back in with the wall color.
Please don’t skimp and paint only one or the other! Unpainted caulk attracts dust and can look dirty very quickly.
Tape to the Rescue
For trickier stuff that doesn’t get painted, like silicone caulk around a bathtub, along tile, or even caulking baseboard along wallpaper, I use painter’s tape! Simply run a line of tape, allowing for a 1/16″ – 1/8″ gap for the caulk to rest. After running and smoothing the bead, remove the tape immediately while the caulk is still wet. You shouldn’t need to smooth the line any further.
Go forth, and caulk!
Guys, that’s it! Now go forth and caulk! Truly, the hardest part about getting the perfect caulk line is not the line itself. Rather, I find that a caulking project is rarely quick; it takes time and patience, and that’s why having a rad playlist or favorite podcast can go so far.
Can I answer any questions, or is there anything I might have missed? I love the satisfaction of caulking unsightly seams (and subsequently painting them as the finishing touch), but I can get flustered with the time commitment. Really, though, what would we do without the greatest DIY tool of all time, right?
PS: This is how we re-caulked along our bathtub, and this is how we caulked our baseboards where it meets up with wallpaper (a tricky one!). And now that you’ve mastered the Art of Caulk, here’s a big cheat sheet on how to paint anything!