How I Overcame My Fear of Horizontal Wood Rain Screen Corners

Written by Dave Walters on Tue, Mar 13, 2018 @ 05:03 AM

Many designers love the clean lines and look of a mitered corner on wood siding. Once upon a time, (last year), I was terrified when architects told me that they wanted to use horizontal mitered outside corners and asked me the best way to do it. Why the fear? Because we love to delight our clients and a mitered horizontal wood outside corner on exterior siding can behave unpredictably. Not anymore.

How come? Wood moves. And the end grain of wood siding is the most vulnerable part of any board. Then, when you expose the siding board to harsh exterior weather conditions, bad things can happen: cupping, end-checking, warping and splitting to name a few naturally occurring misbehavior of wood. Although you may not be able to fight the forces of nature forever, there are techniques that can be used to make the rain screen siding outside corner perform better and last longer.

Field Mitered Horizontal Outside Corner

One method to help manage the natural movement of wood rain screen corners during the acclimation process, and then seasonally thereafter, many savvy designers, woodworkers and master craftsmen go to lengths to create a more reliable mitered outside corner joint. Some of the best techniques to do a field mitered horizontal outside corner on wood siding include; a quirk miter (this blunts the exposed end of the siding and provides a more forgiving visual line at the joint), screwing the ends of the siding boards as close to the end of the board as possible to limit the amount of movement and plugging the screw heads with matching wood to conceal the fastener.

Wood rain screen outside corner with quirk miter, screws and wood plugs.jpg

Expertly installed field-mitered horizontal outside corner for rain screen siding (with quirk miter detail)

These best-demonstrated-practices are as good as it gets with a field mitered horizontal outside corner. However, despite the best intentions and practices of professional designers, carpenters and craftsmen, some of these wood corners may show some movement over time and prolonged exposure. If so, minor repairs and maintenance may be required as needed.

Climate-Shield Rainscreen Horizontal Outside Corner

Closeup of bottom of Climate-Shield Horizontal Outside Corner.jpg Now there is a new and vastly improved horizontal mitered wood siding option. After several years of field testing, Climate-Shield has released its new horizontal wood outside corner. It’s the best joint in town. It is more durable than a field mitered corner and is quick to assemble on site. Not only does the Climate-Shield horizontal corner perform well, but the ‘furnished and installed’ price is about the same as a field mitered corner. A better corner at about the same price. What’s not to like?