Heritage Restoration, Inc.

Let’s Talk About Caulk

Repairs from a tube are our go to, quick fix, get er done, feel good remedy. Yet they are overly used, abused, misapplied, and something that looks pretty terIMG_3530rible. The most popular product from a tube is caulk, which is designed to bridge a gap between two dissimilar materials or planes. There are four main considerations.

  1. The wrong place for caulking usually happens outside where water can get trapped. One example is when horizontal gaps under wood clapboard siding are caulked. It may look great, but it will absolutely trap moisture and make paint peel. The bottom of trim will have the same result. Caulk should never, ever, take the place of flashing or be the way your building manages water. You can pretty much caulk anything that doesn’t get water inside your house, with some exception, like where the tub meets the tile.
  1. Proper caulking follows the basic principle of not using it in gaps wider or deeper than 3/8”. If the gap has no back then use a foam backer rod behind, or you will be wasting caulk and causing it to fail sooner. Also make sure the gap is clean and free of any old caulk.
  1. Caulking is a skilled trade. It’s all about technique. Professionals use stainless steel caulk spatula tooling sets, while homeowners can use a disposable caulk remover and tooling kit. “Tooling” a caulk bead takes time to learn. Using the right tool, some tape, and lots of rags can at least make sure what is left looks good.
  1. Don’t use whatever is in your gun. There are thousands of caulk formulas and even more manufacturers. There are general caulks and caulks designed for specific situations, such as wood to stone transitions. Some stay flexible for a long time or turn rock hard. There are paintable non-paintable. Look for caulk that is designed for the use.  If caulks are solvent based or stay flexible for a long time, practice tooling where it doesn’t matter. Use blue tape on either side of the gap before laying the bead and tool it.

Other tips:

  • Caulks go bad once opened. You can by protective tips or tape the end, but don’t be afraid to throw away a suspect tube.
  • Get a good caulk gun.
  • Cut the caulk tube tip to the width and angle you need. About a 30 degree angle.
  • Use a constant motion and pressure across the gap.
  • Do not use too much. The right amount and the right tooling makes it perfect.

I have seen thousands of dollars in damage from ineffective caulk “repairs”. When in doubt ask, search, or call the manufacturer.