A visit to the caulk and sealant aisle of the hardware store reveals a sometimes bewildering array of caulks. If you are looking to work with concrete, concrete block, brick, stone, gutters, flashings and around chimneys, you'll need to zero in on products containing butyl rubber.
Why Use Caulk?
Caulk is used to fill gaps between building materials and to keep water and air from leaking into spaces where it isn't wanted. It is most often applied using a caulking gun, which generally must be purchased separately. Butyl rubber caulk is most commonly used in extremely wet areas. This makes it ideal for jobs in basements, along outdoor foundations and on the roof. It also works well for sealing gaps in aluminum siding.
Butyl rubber caulk works as a sealant for storm windows and doors. It also can seal downspout and seams in rain gutters. It adheres to fiberglass, wood, brick, masonry, stone, plastic and metal.
Butyl rubber caulk can be painted once it dries, usually after seven days. It also comes in a variety of colors. It is best applied when the temperature is between 40 degrees Fahrenheit and 90 degrees Fahrenheit. (5 degrees celsius to 33 degrees celsius.)
Butyl rubber caulk can be difficult to work with. It can be stringy when applied and it shrinks over time. At cleanup time, paint thinner or mineral spirits are required.
Caulk should touch the surface on three sides. Grooves or areas deeper than one quarter of an inch should first be filled with some other filler as a base.A typical 10.1 fluid ounce tube used in a caulking gun generally provides 30 feet of caulk when the bead size if one-quarter inch. If you don't have a caulking gun, you also can find butyl rubber caulk in a squeezable tube.