Houses take a beating here in the hot, humid south. Strong rainstorms, high winds, hail, freezing rain, and sleet are common causes of deterioration, while ultraviolet radiation quietly does even more damage to siding than all of those combined. The sun is brutal in our environment, and painted siding has never performed well, regardless of the substrate. For that reason, many homeowners select brick or vinyl for their exteriors. However, for the past seven years, we have been installing Diamond Kote, a prefinished LP SmartSide product, and we now have much more confidence offering engineered wood as a siding option.
The Diamond Kote finish has a 30-year “no fade” warranty, and we have yet to see any fading on the siding that we’ve installed. A recent example brought this home: I had to add a mounting block to a seven-year-old project. The company still produces the same color, and to my relief, the brand-new block was a perfect match, despite seven years of UV abuse on the abutting lap siding.
A Complete System
The benefits of this siding aren’t confined to the finish’s ability to withstand harsh elements. Diamond Kote is a system with a unique way of joining courses that the company calls “RigidStack.” The back of the siding has an angled kerf cut (see photos, below) into which a rigid spline is inserted at the factory. During installation of the siding boards, this angled spline wedges behind the top edge of the course below, locking the two courses together. The configuration makes it easier to align two courses, allowing a single person to install a 16-foot length of siding without a helper and without gauges supporting the board. The spline also auto-spaces the lap reveal, which speeds up installation. In addition, a shallow kerf cut into the face of the siding near the top edge creates a visible line to nail along. There’s no guessing where the fastener needs to be placed; just follow the line.
According to Diamond Kote, the spline system helps resist uplift in high winds and reinforces the siding’s ability to withstand impacts, making the installation “375% stronger.” It’s unclear how that is measured, but it is apparent that it would take a lot of force to separate the laps; with the courses locked together, there’s not a lot for wind to grab on to.
Trim. The company also offers a range of trim stock, which has some interesting features that make it intuitive to install. Premade inside and outside corners come with an attached nailing fin for hidden fastening. Without face nails, there’s less touch-up, resulting in a faster and better-looking installation. The outside corners have a built-in channel that allows you to lock in the siding boards, which promises long-term performance and saves considerable installation time.
A recent introduction to the product line is a “rabbeted trim” line for window and door trim. As on the outside corner, this includes a rabbet, or J-pocket, along the length of the trim boards that allows the siding to tuck into the trim, eliminating the need for caulk at the siding-to-trim transition, for a cleaner and faster install. In addition, without caulk, maintenance is much easier.
We always preassemble window and door trim for a more precise, better-looking, stronger, and longer-lasting result. But making the connections, whether we’re using biscuits or pocket screws, has always been time-consuming. The rabbeted trim, however, takes advantage of a small kerf cut into the length of each board. Once a miter is cut, an aluminum L-bracket provided by the manufacturer can be installed to reinforce the joint. The L-bracket fits tightly, creating a nice tension fit so the entire workpiece can be flipped over and snugged together with short T-50 staples to complete the preassembly process.
Utility blocks. The system includes RigidMount light-fixture and utility blocks. If the siding is not ready to be installed, but another trade needs to rough in a hose bib, HVAC line, or electrical fixture, the RigidMount blocks are an easy way to make sure the job looks clean and workflow is consistent for all trades involved. Each block has built-in flashing to make sure water running down the siding is driven out and away.
Starter board. The company also offers a “starter board” that provides a perfect transition at the base of the wall. Engineered wood siding ordinarily cannot be installed within 6 inches of the finished grade, per manufacturer’s instructions. The starter board is a poly-ash material, and the manufacturer claims it will not rot or break down, even if installed at grade. We’ll often rip the top edge off a starter board and use it as a traditional water table, along with a Z-flashing, as the termination for board-and-batten siding.
Color-Matching Support
Since we started using this system, I’ve become an advocate of using a color-matched siding system for both the time savings and the elegance of the exterior. The siding is available in a wide variety of colors, including custom colors and an exclusive “DuoBlend” line that gives the siding a more natural, rustic look. The starter board, corner boards, window and door trim, and mounting blocks come prefinished in all the same colors as the siding. Many pre-bent, color-matched flashings are also available, including drip cap and Z-flashing; they have saved us significant time not only on the metal brake but with finishing, as well. When touch-up paint is needed, the company offers several options, including some handy applicators that help keep the paint from drying out too quickly when we apply it during our hot summer months. Overall, Diamond Kote has been a win for us and our clients alike, and it will continue to be my go-to system.
