Key Factors to Consider When Installing Exterior Trim

Back in the day, exterior trim installation was relatively straightforward. Wood materials were used and methods that were handed down from previous generations provided years of trouble-free service. In today’s age, exterior trim installation requires significantly more carpentry skills and background knowledge of moisture movement along with thermal expansion. Below we will examine the crucial factors to consider when installing exterior trim.

Moisture Content: All wood contains moisture and once it has been built into a structure and protected from the elements, it will begin to dry out and shrink. If you are working on a home that is a few years out, movement from moisture isn’t as much of a consideration. If the house or addition is new, there will be shrinkage of the lumber. If not accounted for during installation, a noticeable gap will form in the eaves.

Trim Selection: Trim material comes in a lot more choices than in former years. This gives homeowners the liberty to match materials characteristics to job requirements, such as allowing plastic trim to come into contact with a driveway. It is essential to understand both the characteristics as well as limitations of your trim as they each require varying installation methods.

Moisture Absorption: Dimensional wood, engineered wood, and fiber cement are considered reservoir materials, meaning they have the ability to absorb moisture, leading to movement, paint failure, and rot. Poly-ash and PVC trim are unaffected by moisture and can be in direct contact with wet surfaces without any adverse effects.

Thermal Movement: Some trim materials expand and contract as the temperature warms and cools, such as PVC. This can further be affected by dark colored finishes, so paints with light reflective value of 55 or higher are recommended. Luckily, poly-ash, dimensional wood, engineered wood, and fiber-cement trim have minimal expansion and contraction movement.

The best practice that you can follow is to follow the manufacturer’s instructions. The bottom line is that trim needs to stay where it belongs and hold the finish long after the initial installation. Professionals at Charles Martin & Son Roofing specialize in carpentry jobs around your home. Contact us for a free consultation and to learn more about what we can provide for you.