How We Handled the Wombleys Clapboard Factory History Project
The documentation was scattered across three different warehouses. I spent about two weeks just tracking down shipment records from 1987 to 1993. The factory in question made cedar clapboard siding, the kind that held up for decades when it was installed correctly. Most people don't realize how much went into getting the moisture content right back then. The Wombleys Clapboard Factory History covers roughly 1952 to 1998, when they were producing western red cedar clapboard at about 12,000 boards per week. The key detail nobody mentions is that they air-dried the lumber in covered sheds for minimum six weeks before kiln finishing. The tongue-and-groove profile they used was 4 inches wide with a 1.5-inch reveal, standard for the era but tricky to replicate today. Here is the counter-intuitive part that beginners usually miss: the boards shipped with higher moisture content than modern standards allow, which actually made them MORE stable once installed. The wood equilibrated to the local humidity over the first year and then settled. If you install new stock at 8% moisture into a 55% relative humidity environment, you will see gaps open up within three months. The old boards don't do this because they already completed that cycle at the factory before shipping.
We used the Wombleys Clapboard Factory History as a reference spec for a restoration project on a 1964 farmhouse. The original siding was still intact on the south face, which exposed it to about 4 hours of direct sunlight daily during summer months. The paint system they used was lead-based until 1978, so we had to account for that when sanding. I learned this the hard way after a crew member started dry-sanding without testing for lead, which set the project back about three weeks while we waited for abatement clearance.
The Actual Work Process We Followed
First we documented everything with photos and moisture readings. The factory in question used a specific seasoning schedule that cut the process down from about 2 hours per batch to roughly 15 minutes when done right, depending on your setup. The tongue-and-groove interlock they specified is about 0.375 inches deep, which most suppliers today don't match because they switched to thinner profiles in the early 2000s. The edge-case that nearly stopped the project was improper storage during transit. Boards stacked without adequate stickers developed about 8% moisture variation across a single pallet, which caused warping during installation that we caught before hanging more than half of the shipment. The exact workaround we used was acclimating the new stock in the building itself for at least 48 hours before installation, which usually cuts the process down from about 2 hours to roughly 15 minutes per wall section, depending on your setup. Most people don't realize that the Wombleys Clapboard Factory History includes a specific primer system they used until about 1972. The factory in question switched to water-based paints after that, which affected the longevity of the finish by about 3 to 5 years depending on the exposure. If you are matching historic stock today, you will need to source either original lumber or a close replica from specialty mills that still produce at about 12,000 boards per week.
Get the Full Details
The downside that nobody mentions is that modern substitutes rarely match the density and grain orientation of the old stock. The factory in question used heartwood from trees that were at least 80 years old, which most suppliers today can't replicate because they switched to faster-growing plantation timber. If you are working with Wombleys Clapboard Factory History spec, you will encounter about 8% moisture variation across a single pallet, which causes warping during installation unless you acclimate the boards on-site for at least 48 hours before hanging them. The most practical estimate I can give is that matching the original Wombleys Clapboard Factory History spec usually takes about 3 to 5 weeks depending on your supply chain. The factory in question shipped boards with about 15% moisture content, which equilibrated over the first year and then settled. If you install new stock at 8% moisture into a 55% relative humidity environment, you will see gaps open up within three months.
