I’ve been having back and forth discussions involving board and batten siding. The opposite side of my discussion (who has been considering using yellow poplar) writes:
“I too was Worried about board and batten, however our barns are 60-100 years old and still are in good shape. At least ones that still have a good roof. No paint or stain has been applied in the past 30 years. So it seems to me yellow poplar is a very good wood for siding. This and the fact that my neighbor can saw my own wood from my farm makes it very attractive to me.”
Yellow poplar has become popular recently for exterior architectural applications, such as siding, due to its reasonable price and relative greater abundance. Unfortunately, decay in yellow poplar lumber can be a serious issue in just a few years.
Until the early part of the 20th century, yellow poplar was used extensively throughout the Mid-Atlantic, Mid-South, and Midwest for exterior applications. As yellow poplar forests in these areas became depleted, the timber industry moved west and south for new sources of lumber. As a result, western and southern pine species replaced yellow poplar. For exterior applications, where decay and insect attack were more likely, redwood and western red cedar became the preferred woods. Cypress was used in the south. The timber from old-growth stands of these species (over 150 years old or more) was rated as resistant to decay and insects.
Now the high-quality old growth sources of redwood, cypress, and western red cedar lumber are in short supply and costly.
Much of today’s redwood, cypress, and western red cedar lumber is coming from second or third growth stands which contain substantial amounts of white sapwood, making them susceptible to decay and insects. In the meantime, the yellow poplar forests have recovered and plentiful supplies of relatively inexpensive lumber are available. Because yellow-poplar was once an excellent species for exterior sidings and trim, many individuals are again using it in those applications.
Yellow poplar is an abundant, fast growing, fast drying, easily worked, relatively low-valued, and excellent hardwood timber species.
Historically, old-growth yellow poplar was used for barn siding, fascia, soffits, corbels, windows and doors, and trim and other applications. Many of these structures remain, demonstrating just how well yellow poplar performed.
Intuitively, it would seem yellow poplar could be used for the same applications today. Unfortunately, many have learned with periodic wetting, the material rots and is no longer serviceable in just a few years.
Two factors probably explain why decay is more common in new lumber than it was in the old. First, young, fast-growth yellow poplar trees will contain a wide band of white sapwood, the live part of the wood which carries water and nutrients through the tree. Well established sapwood from any tree species has no resistance to decay. Large, old-growth trees contained smaller percentages of sapwood and greater percentages of heartwood.
The second reason decay may be more common is modern milling practices. Clear lumber, which is often required for millwork applications, comes from the outside portion of today’s logs, which have more sapwood. As a result, the lumber tends to have a very high percentage of sapwood — it can even be entirely sapwood.
Although it appears the old-growth yellow poplar used in the past has stood the test of time, published data indicates yellow poplar heartwood has little or no resistance to decay. Studies on other species have shown younger timber does not have the resistance of old-growth material.
Considering using yellow poplar for board and batten siding on a pole barn? My reading and research are indicating it may not be the best choice. For durability and looks, steel siding is going to be the winner.