Sealing Exterior Surfaces in the Summer Sun



So… it’s officially the first day of summer and the longest day of the year.

While there is much in that to be celebrated, it is also another reason to choose your caulking materials carefully. Especially if you are sealing exterior surfaces. The outside of a home is exposed to harsh outdoor elements throughout the year. Extreme heat, the sun’s UV rays, and freezing temperatures can cause acrylic caulk to lose its flexibility and degrade. Degraded acrylic caulk can crack and crumble over time, leaving gaps for air and water to seep through. Those leaks can lead to water damage, mold growth, and higher energy bills.

Even though longer exposure to the Summer Sun will bring a smile to most faces, it will also bring more wear and tear to your sealed surfaces. This is why you will want to choose a good exterior grade silicone sealant for all of your exterior applications.

Just a few more expert ideas from Guy Calor, the Caulk King and CaulkWarmer


Pick the right caulk for the job!


The jobs that caulk can do are almost endless but you need to understand which caulk is right for the job you are doing. Here’s a little list of the most common ten types of caulk and the type of projects each can be used for.

1. Acrylic latex caulk. This caulk can be used for both indoor and outdoor projects. It can be used best to fill in gaps in moldings and baseboards and around door and window frames. It is fast drying and can be painted in 6-8 hours of applying. It also comes in different pigments so you can match a color to your job. This caulk is inexpensive and easy to apply. It should not be used in wet places or areas that will endure a lot of moisture. This caulk remains flexible and can be effective for 10-15 years.

2. Vinyl latex caulk. Vinyl latex caulk can be used in a variety of places, both interior and exterior. It is really good for small gaps around windows and doors and can also be used for tubs and showers because it withstands wet and damp areas well. It is also non-flammable and you can paint it.  However, this type of caulk will lose flexibility and harden over time and so it will need to be replaced after about five years.

3. Siliconized acrylic caulk. This type of caulk combines silicone with acrylic latex caulk for a durable, waterproof formula. It is good for both interior and exterior projects and adheres well to most surfaces. It is especially good for tubs, tile, glass and ceramic tile surfaces. It comes in a clear version as well as a variety of colors, is non-flammable, can be painted and is mildew resistant. This caulk remains flexible for a long time and can have a life expectancy of over 25 years. It is also very easy to apply and cleans up with soap and water.

4. 100% Silicone caulk. Silicone caulk is excellent for sinks, tubs, showers , or any other area that has a lot of moisture. It will work well on non-porous surfaces such as ceramic tile, glass and metal surfaces and is mold and mildew resistant. However, this type of caulk does not adhere to wood surfaces, resists painting, and typically only comes in a clear or white color. Silicone caulk can be difficult to apply but does remain flexible when dry. It is non-toxic but it must be cleaned up with a solvent. Silicone caulk does tend to have a strong odor so you should plan your work in a well-ventilated place.

5. Painter’s caulk. This is an inexpensive latex caulk that painters use to fill in holes and cracks before painting. It can also be used in corners to provide a smooth joint where painters are using contrasting colors. This caulk applies easily and smoothly and adheres well to wood, plaster, drywall and masonry. It can be painted within one hour of application and cleans up nicely with soap and water.

6. Tub and tile acrylic sealant. This type of caulk is an excellent choice for all your bathroom and kitchen projects. It is mold and mildew resistant, gives a good watertight seal and adheres to almost all surfaces such as tile, tubs, glass, metal, wood, drywall and plaster. It also comes in a variety of  different colors or it can be painted to match your project. This product is non-flammable,  cleans up with soap and water,  stays flexible when dry, and can last for over 10 years.

7. Adhesive caulk. This is an all-purpose caulk that is especially good for high humidity environments such as kitchens and bathrooms. It adheres well to many surfaces like ceramic tile, porcelain, wood, drywall, plaster and metal. A mildew-cide is a part of the chemical composition which helps to resist mold and mildew growth in damp areas. This caulk can also work as a strong adhesive for replacing loose tiles, molding and other such items. It is easy to apply and only requires a soap and water clean-up

8. Butyl rubber sealant. This is a strong exterior sealant that can be used on wood, metal, concrete and brick. It is good for sealing joints in gutters and around chimneys as well as sealing around skylights and roof vents. It is also the best waterproof sealant for house foundations. It is difficult to apply and slow to dry and clean-up requires a solvent. This sealant has a life expectancy of anywhere from  2-10 years.

9. Roof repair caulk. This caulk is a butyl rubber/asphalt formula that works well on roofing, skylights and for sealing flashing. It can also repair small areas in asphalt. It is weatherproof and waterproof and can be used on wet and dry surfaces. This caulk can also be painted. It requires mineral spirits for clean-up.

10. Concrete and mortar repair caulk. This is an interior/exterior caulk that can repair cracks and holes in brick, concrete, stone, stucco, and metal as well as textured walls and ceilings. It has a textured finish and retains some flexibility when dry. It can be painted and cleans up easily with soap and water.

You should always read the manufacturers label before choosing a particular type of caulk for your project to be sure you have found the right one for your project.

Just another expert idea from Guy Calor, the Caulk King and CaulkWarmer

Caulking Windows and Exterior Doors

window draft

Caulking Windows and Exterior Doors  –  Caulking along the outside of the frame of a window or door is important in sealing from water infiltration which is absolutely necessary in preventing water damage. A good rule of thumb is to apply a bead of caulk anywhere two dissimilar materials meet… brick and wood; wood and glass; wood and metal, etc.

Caulking Windows – Check for window drafts by carefully holding a stick of incense up to each frame and watch the smoke to see if there is a leak. (Be sure to remove all curtains and drapes first to avoid a fire.) Then use caulking or weatherstripping to seal the cracks. Another method is to work with another person on the outside, have that person blow a hair dryer around the outside of each window while you hold a lighted candle inside. If the candle flickers or goes out, you need to caulk or weather strip around the frame.   Do not seal the exterior window weep holes shut, as these allow any water or moisture that does get into the window area to get out.  Never use oil-based caulk to seal the seams of an insulating window. The oils in the caulk can degrade the bond around glass allowing moisture to seep into the house. The most obvious symptom of this problem is seeing your windows fog up during the summer.

Caulking Doors – All doors (entries, garage doors, and pet entries) need special attention. Problems are common where the doorframe meets the threshold. A thin bead of caulk can prevent water damage here. Also caulk the areas where trim meets the doorframe or siding. Don’t try to caulk the entire door jamb before going back and smoothing it out, do that as you go. Caulking starts to skin over quite quickly and then you can’t smooth it out properly.

Just another expert idea from Guy Calor, the Caulk King and CaulkWarmer

Caulking Wood Surfaces

caulking wood

Caulking Wood Surfaces –  Do not caulk bare wood surfaces.  Caulk will not last as long if applied to sun-damaged wood. Wood that is exposed to direct sunlight for as little as two  weeks will result in a weaker bond than normal.  Caulk adheres best to primed or painted wood. The wood should at least be primed before applying the caulk and it will adhere even better if the wood surface has been painted first.

Just another expert idea from Guy Calor, the Caulk King and CaulkWarmer!

Saving Unused Caulk


Unused Caulk – There actually is a way to save the unused caulk left in the tube, rather than tossing it out. You can always try to store your cartridge for later use using a plastic electrical connector as an easy way to quickly seal and reopen the tube. If you can’t find a connector, place a 2-inch nail into the end of the nozzle, then wrap the entire nozzle tightly in plastic wrap or aluminum foil. This will help keep the caulk in the nozzle from hardening for use at a later date, but the very best idea is to use the wax from a wax toilet gasket ring (you can buy one for about $2.00…. and one will last you almost forever). Put the wax in a small container, like a router bit case with a top on it, this keeps the wax from getting all over, and the wax case is small enough to put in your tool box and take it with you. After you caulk something and have some left over, just push the tip of the caulk tube into the wax (approx. a couple of inches) and it seals the tube closed.  Later, when you need to use your half used tube, put it in your gun and squeeze out the wax and you are in back in business with no waste!

Just another expert idea from Guy Calor, the Caulk King and CaulkWarmer

Unclog that Caulking Tube


Clogged Tube – If your tube of caulk becomes clogged by dried caulk from the last time you used it, you may not have to throw it out. You can actually fix this minor inconvenience quite easily. Take the tube and cut off the nozzle end so that the hole is slightly larger than the first cut. Next, drive a screw into the nozzle end of the hardened caulk and use the screw to pull the hardened caulk out of the nozzle. A screw with coarse threads, such as drywall or deck screws, will work the best.

Just another expert idea from Guy Calor, the Caulk King and CaulkWarmer

Cleaning the Caulking Surface


Clean Surfaces – Making sure that the surface you are going to caulk is clean and well-prepared is essential to achieving good adhesion and a smooth bead.

  • Clean off any dust or dirt particles with water.
  • Do not use soap.
  • Remove any remnants of old caulking. New caulk will not adhere well to acrylic caulk that has been cured and will not stick at all to cured silicone caulk.

After you have removed most of the old caulk with a blade (being careful not to scratch the surface), you can apply a concentrated mildew killer. Finally, swab the joint with rubbing alcohol to remove soap scum, body oils, and other residue. Rubbing alcohol dries quickly and leaves the surfaces impeccably clean so the new caulking will adhere well.

Just another expert idea from Guy Calor, the Caulk King and CaulkWarmer!