| Property owners, building management, engineers and | | | | which requires the paint material to expand at the |
| architects are plagued with the issue of expansion | | | | same rate as the substrate. If different materials are |
| and contraction within a building. Regardless, whether | | | | utilized to construct the exterior wall, each material |
| the building is a commercial, industrial or residential | | | | will expand at a different rate requiring a joint to |
| structure, the edifice is constantly expanding and | | | | separate the various materials. Therefore, whenever |
| contracting related to the ambient temperature. As | | | | two materials meet on the exterior façade a |
| the temperature rises the building expands, | | | | joint should be provided to separate each material. |
| temperature decreases the building contracts. When | | | | The joint systems utilized on building exteriors consist |
| using different type materials, the building | | | | of various materials; rubber, silicone, urethane and |
| components will expand and contract at different | | | | metal. Typical construction practice is to install the |
| rates. Concrete, brick, masonry block, steel, wood, | | | | joint sealant or expansion joint material as the |
| vinyl and plastic, each have a different rate of | | | | exterior façade in erected. The exterior color, |
| movement. Dissimilar materials can have extensive | | | | in the form of paint, is installed over the exterior |
| affects on joints over long periods of time. | | | | façade during construction. When installing paint |
| To best describe how a typical building expands and | | | | products over a silicone material during construction, |
| contracts, imagine a dry sponge representing the | | | | than failure will occur. Typical paint products do not |
| exterior of the structure. The dry sponge is at its | | | | bond to silicone materials. Once a failure occurs within |
| absolute contraction point. Saturating the sponge; it | | | | the painted surface moisture will infiltrate the exterior |
| allows the sponge to swell to its absolute expansion | | | | façade causing further failure of the painted |
| point, in all directions. As the moisture is released | | | | surface. In addition, typical paint products are unable |
| from the sponge it maintains a median state when | | | | to expand and contract at the rate of the substrate |
| the ambient temperature hovers around 70 degrees. | | | | that it's applied over; thus causing failure within the |
| The ambient temperature rises the building expands, | | | | painted surface. Reducing the longevity of the paint |
| the ambient temperature decreases the building | | | | protection to the building envelope. |
| contracts. So ask yourself, how does the expansion | | | | Technology has developed various systems that can |
| and contraction of a building affect the building | | | | alleviate the problems that occur during design and |
| components? | | | | construction; provide the moisture protection and the |
| Typically, engineers and architects take in | | | | longevity expected by property owners. These |
| consideration of this movement process when | | | | exterior components are capable of handling the |
| designing structures. Expansion joints are utilized to | | | | expansion and contraction requirements of the |
| compensate for the expansion and contraction of the | | | | various materials. Expert exterior contractors are |
| edifice. Expansion materials are placed within the joint | | | | familiar with the various products and systems. When |
| to seal against moisture intrusion. Unfortunately, this | | | | properly installed the building envelope will continue to |
| is a component that requires maintenance every 5 to | | | | provide the protection required for over 30 years. |
| 7 years. However, the design team fails to consider | | | | Ultimately, this reduces the maintenance budget for |
| the exterior coating components, such as the painting | | | | the building owner, reduces moisture infiltration and |
| system. The exterior wall expands in all directions, | | | | reduces the possibility of mold growth. |