Encyclopedia

of Home Improvements

*Caulking*

Thanks to the space program today we have wide variety silicon compounds & caulking materials. We use them every day to close up the gaps, cracks, joints, and variety of other areas of your home. The most common areas that typically need caulking are windows and doors, moldings, bathrooms and kitchens. Your house is always expanding and contracting causing gaps to form. Caulk is usually product of choice to clean these up.

Water based caulks combine the benefits of water-based products with the adhesion, flexibility, and durability of silicone and polyurethane. The trick is to choose the best caulk for the particular job at hand. There is wide range of water-based caulks, from painter's caulks to elastomeric sealants. Latex caulks can be used just about anywhere as long you choose the right product for the job. Some water-based products are flexible and whether resistant for exterior joints, others intend to hide only interior seems that are to be painted. The silicone is a little more difficult to use and requires solvents to clean up. Most silicon cannot be painted. Many times they are better in more difficult situations that acrylic latex caulks. Silicone has a much better adhesion quality, and will expand and contract with weather. Paint will not adhere to silicone.

Synthetic rubber products like silicone or polyurethane represents some of the most flexible and cleanest curing products on the market. These qualities make them ideal for exterior joints likely to expand and contract. They adhere to most substrates; can be applied in wet and cold weather and resist mildew. They have the ability to stretch without breaking and have the ability to recover. They are paintable with water base paints and come in clear formulas that cure more transparent than any other caulk.

Modified silicone polymers represent the newest type of sealant available. Like latex products they are easy to apply. Like silicone, they can be applied in extreme temperatures that withstand rain almost immediately. Like polyurethane they are incredibly durable adhere well to all materials. They are flexible, paintable with water base paints, cure quickly, and don't shrink. They are the best product for sealing around exterior penetrations like Windows, doors, and vents.

Don't be afraid to read the labels and ask questions. Every time I go into a home center I find a new type of caulk for a different job. There are caulks for painting inside, painting outside, for wood, vinyl, aluminum, concrete tile etc. You get the message

Probably the most important thing when applying caulk is to thoroughly clean project area. Make sure to scrape away the old caulk and dirt so that the area is thoroughly clean, cut the tip of your caulk tube at a 45-degree angle and puncture the inside seal. By squeezing the trigger easily and consistently over the gap, lay down a small bead of caulk. You can always add more if you need to. There is nothing worse than a big globby bead of caulk!! Using a wet rag smooth over the joint and clean off the edges to make a nice neat job. For larger cracks you may have to apply the caulk several times.

One trick to making a nice straight caulk line is to lay down masking tape along the area to be caulked. Applied a bead of caulk, wipe it down with a wet rag, and then remove the tape. This should provide you with a really nice razor sharp straight edge

Painter's caulk: Inexpensive latex caulk is often used by painters to plug holes and cracks prior to painting. It can also be used to provide a smooth joint in a corner where textured materials meet. This allows the painter to paint a very straight line in the corner when using contrasting paint colors.

Acrylic latex: Paintable, acrylic fortified caulk for both interior and exterior applications. Cleans up with water.

Siliconized latex: Very durable, latex caulk with silicone. Available in colors and cleans up with water.

100% silicone: Silicone caulk is great for non-porous substances. It is the best choice for sealing ceramic tile, glass and metal surfaces, but is less appropriate for porous surfaces like wood and masonry. Silicone caulk remains flexible and is impervious to water. It cannot be painted and must be cleaned up with solvent. It also has a sharp odor when curing. Requires adequate ventilation. Usually available in either clear or white.

Tub and tile: Acrylic sealant gives a flexible, watertight seal. It is mildew resistant with water cleanup.

100% silicone kitchen and bath sealant: Has the same characteristics as plain 100% silicone sealant.

Gutter and foundation sealant (Butyl Rubber): Can be used on metal, wood or concrete. Appropriate for use in areas which experience extreme temperature variations. Requires solvent clean-up. It is often used on metal flashing and around skylights.

Roof repair caulk: Convenient butyl rubber/asphalt formulation for sealing flashing, roofing, skylights, etc. Cleans up with mineral spirits

Adhesive caulk: Used as an adhesive during the installation of sinks, countertops, etc. Dries harder than other caulks, but is less flexible.

Concrete and mortar repair: Retains some elasticity to remain in cracks in mortar and concrete. Cleans up with water





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