Do-it-Yourself - Replacing door and window caulking

By Hklbrries

Q. I want to replace a lot of caulking around the outside of my house, especially around windows and doors where I suspect there are air and water leaks. Much of the old caulk is cracked, discolored, or has pulled loose. How do I clean the joints before re-caulking and what type of caulk should I use?

A. Some old caulk, especially silicone, retains enough flexibility to be pulled off in strips. Other caulks can get hard and must be removed by scraping.

To scrape, use a sharp 5-in-1 tool, which you can buy at most home centers or hardware stores. In addition to having a sharp blade several inches wide, this tool has a hooked side that can be used to pull out chunks of loose caulk.

If some caulk resists removal, you can sometimes soften it with a solvent such as 3M Caulk Remover. (If you can’t find a caulk remover locally, search for Chemical Caulk Removers on the Internet.) A heat gun on moderate-heat setting will also soften caulk, but extreme caution must be used around flammable materials, especially dry wood. A dangling electrical cord is also awkward and dangerous when used on a ladder.

When you have removed the old caulk, brush dirt and loose particles from the joints with an old paint brush.

The array of caulks at many home centers and hardware stores is truly mind-boggling, but it is not difficult to narrow down the choices.

Most do-it-yourselfers prefer water-based (latex) caulks that clean up with water, have little odor and are easy to smooth with a wet fingertip. Latex caulks can usually be painted within a few hours. Most latex caulks will adhere to many surfaces and some will last for many years. Check labels on the caulk cartridges for detailed information.

Silicone caulks are also a good choice, but most silicones are not paintable and must be cleaned up with mineral spirits; some users find them tricky to smooth.

Some professionals prefer urethane caulks, which have superior adhesion to most surfaces and are highly water resistant. Urethanes must be allowed to dry thoroughly before they can be painted, however, and full drying can take several days.

Ingredients

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Preparation

Step 1

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