how to

caulk interior windows


recommended products:
DAP® 3.0™ Advanced All-Purpose Sealant, DAP® DYNAFLEX 230® Premium Indoor/Outdoor Sealant, and DAP® ALEX PLUS® Acrylic Latex Caulk Plus Silicone can be used to seal cracks and gaps up to ½" for energy savings and/or prior to painting for a professional-looking finish. For gaps above ½" in diameter, use a foam backer rod first, then apply the caulk over the backer rod.

project instructions:

  1. Be sure to read the entire package to ensure you have all materials the job will require and to budget for dry times in your project. Carefully review all safety precautions on the package.
  2. Clean and dry the surface you will be sealing to ensure it is free of all dirt, dust, grease, old caulk and debris. (To remove old caulk, use DAP® Caulk Be Gone® for latex caulks or DAP® Silicone Be Gone® for silicone caulks; or a utility knife or a caulk removal tool. Once completely removed, wipe away any debris. Use a rag to wipe the joint surface with rubbing alcohol or an over-the-counter disinfecting spray, rinse thoroughly with water, and dry.)
  3. Apply the painter's tape to mask off areas around the joint where the caulk should not appear and to help give a straight caulk line.
  4. There are many different nozzle designs on caulk cartridges. Read the instructions of your selected product for instructions on cutting the nozzle. Some nozzles have an inner-foil lining that needs to be punctured or a removable nozzle covering an inner plastic seal that also needs to be cut.
  5. Load the cartridge into the caulking gun. Applying steady pressure to the trigger, fill the joint around the window with an even bead of caulk. If you have selected a product in a squeeze tube, cut the nozzle at a 45° angle with scissors or a utility knife and squeeze the product into the joint. It is best to push the caulk ahead of the nozzle to ensure that it gets into the joint for a proper seal. Follow using a finishing tool such as the DAP® Pro Caulk™ Tool Kit to smooth the bead for a professional-looking finish.
  6. If you applied painter's tape, remove the tape prior to the caulk skinning over. To correctly remove tape, lift the edge up at a 45° angle away from you, and carefully place in a trash can.
  7. Wipe away excess caulk with water and a damp cloth before the caulk dries. Excess dried caulk will need to be cut or scraped away.
  8. The DAP CAP™ is ideal for storage if later use of a partially-used container is desired.

paintable, clean-up, and other information:
Generally, latex-based products are paintable and are soap and water clean-up. Silicone products are not paintable and must be cleaned up with solvent cleaners. Carefully read all label instructions before beginning your project. See the following product attribute chart for select DAP products providing valuable information to aid in your product selection.

which product should I use?

DAP® 3.0™ Advanced All-Purpose Sealant DAP® DYNAFLEX 230® Premium Indoor/Outdoor Sealant DAP® ALEX PLUS® Acrylic Latex Caulk Plus Silicone
quality advanced best better
paintable yes yes yes
time before painting 3+ hours 2+ hours 2+ hours
clean-up mineral spirits soap & water soap & water
unique feature Caulk and expose to water after just 3 hours Waterproof and Paintable - Outstanding Durability and Adhesion America's Number One Seller

this is a great project to:

  • reduce air flow, and therefore reduce heating & cooling bills
  • create a smooth surface prior to painting
  • eliminate openings for insects to enter your home