Caulk Like a Pro: How to Get Flawless Lines Every Time

While there’s no substitute for practice and experience, we’re here to help flatten the learning curve

Properly sealing cracks and gaps with caulk will protect and beautify your home—and save you money in the long run. Andrey_Popov/Shutterstock

Caulk fills and seals gaps around doors, windows, sinks, tubs, toilets, pipes, and wiring. It gives edges an attractive, seamless finish and keeps water and bugs from getting into the house where they can cause damage. Properly sealing windows, doors, and even your garage door is also a sure way to help to reduce heating and cooling bills.

But don’t open that tube just yet. First, you must prepare the surface, as applying new caulk over old caulk is a big no-no.

Goodbye, Old Caulk

Unless you’re dealing with completely new construction, you need to remove all the old caulk. (If you’re working with new construction, skip to “Squeaky Clean Surface” below.)