Why Caulking is Done
Caulking all concrete joints will prevent (or at least reduce) water infiltration into the concrete and sub-grade. This also prevents the need to mud-jack sunken concrete slabs (this due to water infiltration to the sub-grade). Expansion joints allow the concrete to expand without cracking. Control joints are either tooled or cut to allow concrete cracks to limit in length and be controlled in a particular area.
Over time these control joints themselves will start cracking causing an open door for water to come in and play a role in the removal and movement of the sub-grade thus causing the slabs to shift.
Expansion joint material is placed where needed upon a fresh concrete pour, but this expansion joint material itself does not repel water and keep water from infiltrating the sub-grade. It is only used to keep the concrete slabs from coming into contact with other slabs preventing a collision. After the 30 day period, after the freshly poured concrete has fully set up, it is important to cut down all expansion joint material and caulk all joints to keep water out.
Sealing concrete is highly recommended as the first line of defense into protecting concrete. After moisture is absorbed into concrete hot and cold temperature make for moisture to contract and expand hence the cracking in concrete ultimately destroying concrete. Sealants penetrate deep inside the surface and fortify the corrosion resistance even more. Sealants make the concrete surface easier to clean and maintain and they also increase the durability and longevity of the concrete. Sealing concrete also prevents accumulation of dirt and grease on the surface, and hinders penetration of chemicals, water, UV rays, etc.
Concrete's Worst Enemy
Water that takes on any form can destroy the finish and reduce the life expectancy of concrete. When concrete cures the water in it evaporates so it already has a tendency to absorb water. And with the constant presence of water it will weaken the bond of the surface materials. And once that surface is weakened it begins to wear off as it opens the concrete to rapid failure.
Siding, Trim, Windows, Doors
Caulking also protects your home or business from unwanted moisture that penetrates the exterior of your home. Prolonged exposure of moisture causes serious damage to the exterior of your home. If you are having water leakage coming in from any door(s) or window(s) then most likely it is because the door(s) or window(s) have an area where caulking has failed and need to be resealed.
Over time exposure to moisture in areas around the exterior of your home or business can and will cause excessive water damage and wood rot if not sealed properly and/or right away. In worse cases the siding from prolonged exposure will need to be replaced causing a simple maintenance service into a larger job.