Outdoor air is probably infiltrating your home and increasing your energy bill. Summer heat and humidity can penetrate openings, forcing air conditioners into overdrive. In the colder months, frigid air coming in means that heating systems are also operating more frequently.

Fortunately, caulking and weatherstripping can seal leaks around your windows, doors, and trim. This process involves locating gaps and cracks and sealing them to block outdoor air from entering living spaces.

Here are three straightforward caulking steps to prevent air from coming in, improve comfort, and cut energy costs.

Step 1: Find the Leaks

Before beginning the caulking process, pinpoint leakage spots. Thoroughly inspect interior and exterior areas to discover drafts and openings that may be letting in outdoor air.

You can usually find these openings in doors and windows, as well as in the basement, the attic, outlets, plumbing, fireplace dampers, and seams between materials like wall corners. Scan roof lines, siding, trim, and masonry for holes, cracks, gaps, and deterioration. Consider recruiting an energy auditor to perform blower door tests to determine precise leak locations.

Drafts are simpler to detect during winter. On gusty days, position lit incense sticks or feathers near potential leakage points, observing if smoke or feathers waver. 

Alternatively, on hot summer days, wave your hand over cracks to feel if any warm air is entering your home.

Step 2: Select Caulk or Sealant

While many use caulk and sealant interchangeably, some manufacturers differentiate the products.

Caulk usually denotes latex or silicone compounds for general sealing purposes. Sealants tend to offer superior elasticity and grip when bridging joints between dissimilarly expanding and contracting materials.

One high-performing sealant is PVA wood glue, like Titebond WeatherMaster. It adheres tenaciously to most building materials, exhibits minimal shrinkage, fills gaps up to 1 inch, and remains permanently flexible. It comes in over 200 colors to match existing siding.

Alternatively, you can paint WeatherMaster after one hour of drying.

Home improvement retailers offer various caulking and sealing compounds for homeowners. Compare options based on what you need to seal and attributes like water resistance, flexibility, durability, and gap-filling capacity. For extensive caulking projects, consider hiring a handyperson.

Step 3: Apply the Caulk

For gaps exceeding 1⁄4-inch wide by 1⁄2-inch deep, first inject expanding spray foam. Verify the area is clean and dry before caulking. Remove old caulk, dried foam, dirt, and debris using isopropyl alcohol.

To achieve straight caulk lines, border gaps with painter’s tape. Position a caulk gun at a 45-degree angle and steadily apply a continuous bead without big gaps, though you should allow for small spaces to permit expansion.

Once finished, smooth the caulk into cracks using a fingertip or plastic smoother.

Allow the caulk to begin skinning while still tacky, then carefully remove the tape for precision results. Plan to cut fully cured caulk with a utility knife before re-caulking, and respect product guidance for proper drying times before water contact or temperature extremes.

Today’s Homeowner Tips

Heat cartridges to enhance cold-weather flow, snip nozzle tips to match the desired bead thickness, and apply caulk or sealant vertically when possible to prevent sagging.

So, Is Sealing Your Home’s Gaps Worthwhile?

Caulking to seal air leaks provides tremendous benefits, making the effort worthwhile. Blocking uncontrolled airflow prevents indoor air quality issues like dust and pollen intrusions, which aggravate allergies and respiratory problems. Sealing gaps also deters pest entry while retaining conditioned air for improved comfort and energy savings.

While DIY caulking is feasible, large projects or hard-to-reach areas might justify hiring an expert. Pricing varies based on the linear footage, location, and products selected. However, sealing cracks could reduce your energy bills by 30% — quickly paying for itself.

FAQs About Home Caulking

What areas should I caulk?

Prioritize exterior envelope penetrations — particularly near windows, doors, pipes, wires, vents, fans, fixtures, corners, and transitions between dissimilar building materials.

What tools do I need?

Gather caulk, guns, cleaners, painter’s tape, plastic smoothers, utility knives, rags, eye protection, and drop cloths before starting the caulking or sealing process.

How do I remove old caulk?

Slice through the cured caulk using a utility knife. More pliable caulk may peel off in strips by hand. Always clean with isopropyl alcohol before freshly applying caulk.

What’s the difference between caulk and sealant?

Sealants usually offer superior elasticity versus caulk when bridging joints between materials expanding/contracting at varying rates. However, the terminology often overlaps, so carefully analyze the technical specifications.

Can I caulk vinyl siding?

Avoid caulking gaps between vinyl siding and trim pieces. Slight movement facilitates drainage/airflow, preventing moisture issues. Instead, install trim coil or J-channels.

Editorial Contributors
avatar for Jonathon Jachura

Jonathon Jachura


Jonathon Jachura is a two-time homeowner with hands-on experience with HVAC, gutters, plumbing, lawn care, pest control, and other aspects of owning a home. He is passionate about home maintenance and finding the best services. His main goal is to educate others with crisp, concise descriptions that any homeowner can use. Jon uses his strong technical background to create engaging, easy-to-read, and informative guides. He does most of his home and lawn projects himself but hires professional companies for the “big things.” He knows what goes into finding the best service providers and contractors. Jon studied mechanical engineering at Purdue University in Indiana and worked in the HVAC industry for 12 years. Between his various home improvement projects, he enjoys the outdoors, a good cup of coffee, and spending time with his family.

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Lori Zaino

Lori Zaino is a freelance writer and editor based in Madrid, Spain. With nearly two decades of editorial experience, she’s written and edited for publications like Forbes, CNN, Insider, NBC, Newsweek, The Points Guy, The Infatuation, and many others. Having just completed her first home renovation, she’s more interested in home improvements than ever, dedicated to bringing you fresh and accurate content to help you update your living spaces.

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