Audrey 
Applying caulk is a DIY task that almost anyone can learn to do well. It’s more than simply a case of applying the right amount of pressure though, it’s a nuanced skill and the more often you practice it, the better you’ll get and the more even and reliable seal you’ll achieve.
It is a simple job but takes time to master. Luckily it doesn’t require specialist tools and equipment but just a few items and a steady hand.
What is it used for?
Caulk is applied to gaps for a neat finish and is typically used between skirting boards and walls. It can also be used in the corners between walls and ceiling coving to produce a smooth edge. Alternatively, it can be used around windows, guttering and even boats, though different caulk sealants are available for different applications. Ideally, a premium acrylic or silicon decorator’s caulk should be used, that is fast-drying and can be painted over in as little as a few hours.
Preparation
First, any previous caulk must be removed, and this can be done with a putty knife, which peels away the caulk. It can be an incredibly satisfying job. Then ensure you sand away any rough edges for a smoother finish and clean up any dust and debris. Finally, remove any dirt and grime with a suitable cleaner, such as simply washing up liquid.
You should then be ready to load up your caulking gun. These are either supplied “ready-loaded”, so you just need to snip the top off and start caulking, or as guns where you buy your own caulk and then load it into the device. Either way, always squirt out a little caulk and wipe it away with a paper towel before starting, as a little might have dried at the end of the nozzle.
Application
Start from a corner and try to do each area in one go to ensure a smoother and more consistent finish. The nozzle should rest along the wall and trim edge, and you should be pressing gently until the caulk is applied, moving slowly as you go to ensure a straight line.
Removing excess caulk can be tricky, particularly if it’s fast-drying caulk, so avoid doing it too quickly and keep a damp cloth on hand to smooth over the edges after application. You can also simply use your finger if you don’t have a damp cloth or sponge to hand. Finally, clean the edges and move on to the next edge until you are finished.
Maintenance
Once the caulk has been applied, you might want to paint over it, particularly the acrylic sealant used to caulk skirting boards. Painting over the caulk is fine if you allow it to dry properly first and use suitable paint.
As for waterproof caulks, like silicon, that are used in kitchens and bathrooms, no real maintenance is required but you might want to watch out for mould build-up. Also, you might need to reapply the caulk every 10-20 years.
