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Caulking up a storm

​I can tile a backsplash, install a toilet and frame in a new closet, but until I became interested in energy efficiency, the thought of caulking gave me a bad case of the hebejeebees.

It’s not like laying a straight bead of caulk is complicated. It just takes practice and a little bit of knowledge, which you won’t learn from reading the small print on the label. Me? I learnt the hard way and have trails of wobbly beads and exploding caulk tubes to prove it. If you’re a caulking novice, hopefully you can learn from my mistakes and seal your gaps and cracks before winter like a caulking pro.

Choosing the right product for the job

Caulking is used for more than windows. There’s caulk for the bathtub and for attaching an undermount sink to the underside of a counter. There’s even sealant for your chimney and contractor’s glue that comes in the same type of tube that caulk does. The confusing part is that in the hardware store all these products are displayed together, so finding the right tube of caulk can be a bit of a challenge.
It’s not hard for a novice caulker to be overwhelmed by the selection of
different types and brands.

Look for caulk that says on the tube it’s for windows and doors. If you’re over 40 (like me), make sure you bring your reading glasses when shopping as it’s sometimes hard to find this information on the label. But remember this. The side of the window you’re caulking (e.g. interior or exterior) will determine the type of caulk you need.

You can also buy caulk in colours other than white. Some are also paintable and others are clear. For example, if you’re caulking the interior window sills and frames and plan to paint them white, use a paintable white acrylic/latex caulk.

The small print states for windows and doors, but how will you know if it’s for
interior or exterior?

This simple table can help you choose the right product for your job.

​Type ​Good for ​Pros ​Cons
  • ​interior side of windows
  • filling gaps around baseboards and moulding
  • ​easy water clean up
  • ​may not last as long as silicone
  • can shrink or crack over time so don’t use outdoors
  • ​bathtubs
  • sinks
  • exterior windows
  • lasts longer than acrylic
  • waterproof​
  • requires mineral spirits to clean up (If you’re a novice caulker, the mess will be hard to clean up.)​
​Acrylic/latex with silicone (hybrid)
  • ​interior windows
  • benefits of silicone with easy water cleanup​
  • not for use outdoors​

Like a nail needs a hammer, caulking needs a gun

Successful caulking is all about the application. You can buy caulk in those little squeeze tubes for small jobs, but if you want to be a good DIYer, I recommend using tubes of caulk and investing in a caulking gun. They range in price from $5 to $20 and come in different sizes to match the tube size.

Which caulking gun is right for the job?

The secrets to caulking no one told me

In the painting aisle at Home Depot one day, I sheepishly asked the clerk why the tube of caulk I had bought the day before had exploded all over my pants. “You have to poke a hole in the seal,” she explained. “Huh!” I thought. “Where does it say that on the label?” So you don’t have to repeat my mistakes, here are a few tips for first timers:
  1. Using an exacto knife, trim the tube tip off at a 45 degree angle. The trick is not to trim it down too far. If you do, you’ll end up with a fat, blobby bead.
  2. Stick a long nail or piece of wire down the tip and poke a hole in the interior seal. Failure to do this can result in the caulk exploding out the bottom, creating a big mess!
  3. After you lay your bead of caulk, moisten your finger in soapy water and use it to “tool” (smooth out) the bead. I’ve found those gimmicky smoothing tools are a waste of money and make a big mess. However, if you’re using 100 per cent silicone, you may not want to get it on your finger. In this case, try a plastic spoon to tool.
  4. If you don’t use the entire tube of caulk, either throw it away or buy a cap. If you don’t cap it, the remainder will dry up and be useless.

Cut open the tip at a 45 degree angle. You can make the cut bigger if you need to, but you can’t make it smaller!

Once you’ve cut off the tip, stick a
nail or wire down the tube to break
the seal on the inside.


An even, steady hand makes for a nice, straight bead.

Tooling the bead. I used brown

caulk here as white wouldn’t show in the photo.

Practice makes good enough

I’m not saying you’ll be laying beads with surgical precision, but hopefully you won’t be subjected to a breathalyzer test based on the state of your blobby bead lines. It just takes practice. I learned the trick of keeping my hand steady and the bead of caulk straight by practicing in hidden corners. And yes, over the years, I’ve made many attempts that I’ve had to scrape off and redo.

Learn more about caulking