If you had to describe a friend as “Wasted Away Again in Margaritaville”, or stranded in the Who’s “Teenage Wasteland”, or even that they “Wasted” years crying with Carrie Underwood, it would definitely sound like they were in dire straits. And unless you get your money for nothin’, waste in the builder’s world is a bad thing. Sometimes waste is simply part of the construction process, but how a builder manages it can often be the difference between profit and loss, or under or over budget. Waste Factor in Mouldings. Manufacturing custom mouldings is a fascinating process where rough cut hardwood lumber is turned into beautifully shaped trim for the home. As with a sculptor chiseling away at a block of granite, there are lots of pebbles, wood chips and dust to sweep up after a days’ work. In the moulding world we call the excess wood that is removed – the “waste factor”
It’s not intentional waste, or quite as tragic as the songs would make it sound, it’s just a necessary part of the process. The nice thing about waste factor in a controlled manufacturing process (like moulding) is that it’s predictable. Sure, it will vary based on the species of wood or grain patterns requested by our clients, but those variables are known up front and get “factored” into the mill’s estimate of the board footage of lumber that will be needed for the moulding run. Framing Lumber Waste. Just like moulding, there is a built in waste factor for lumber when framing a house. You see the waste at every jobsite in the form of plywood or OSB triangles left over from roofing the house, or in the short pieces of 2×6 with angled cuts from rafters. It is also common from odd lengths of lumber cut from a standard length of board, for example, a 6’6” header cut from an 8’ piece. Since wood is an organic product susceptible to movement (crown, cup or split) when subjected to changing moisture content or direct sunlight, carpenters also expect a certain amount of “cull” waste, usually less than 5%. An experienced carpenter can minimize culls by saving, cutting up and using them where short pieces are required. Like the mill’s waste factor, these sorts of waste are somewhat predictable. Lumber estimators often add 10% extra for dimensional lumber (2×4 – 2×12) and 15% or more for roof decking, depending on how cut up (or complicated) the roof is.
Challenge for Lumber Estimators. I recall a time sitting down with a noted architect who was very excited about his new CAD/BIM software that could purportedly estimate (or take-off) the entire lumber package for a high-end custom home. Until we started talking about waste factors. You see, it is fairly easy to count lumber in a house as designed or after it has been framed up, but quite difficult to count the lumber that was ordered and delivered to the jobsite but never installed. What do you mean, you ask? Where did it go if not installed? Unfortunately, either in the dumpster, or if the jobsite is not secure, who knows where?
Unpredictable Lumber Waste. What drives estimators crazy is not necessarily the complexity of the plans, or even the fact that they are expected to read the minds of carpenters who will frame the house. What stresses them out is that they will often be blamed for a “bad estimate” when they have no control over the unpredictable waste. This is the waste that blows budgets, eats into the builder’s bottom line, and is often hidden from view – it includes:
• Over-ordered or mis-ordered lumber that is not protected and promptly returned for credit • Changes to the plans or framing mistakes that cause tear-out and re-frame • Theft from the jobsite • Weather damaged lumber not protected from moisture and sun • Bracing or scaffolding built on-site by trades and not re-used in project • Hurried, careless or inexperienced carpenters • Overly conservative framers who use more wood than called for in plans “just to be sure”
There is simply no way for a lumber estimator to predict or account for such waste. It can be vastly different for every jobsite based upon the framer, management of the site, weather, security and the size and speed of the framing crew (haste tends to make even more waste).
Sawdust and Savings. The phrase used in our industry for great coordination between the framer and the lumber company is that there was “only sawdust left over”. Of course that is impossible, but how many dumpster loads of wood were hauled off from your jobsite? How many pieces of 2×4 in the dumpster longer than 16” could have been used for blocking in walls or lookouts for soffit overhangs? How many nail-riddled scaffold or bracing boards? How many mud-encrusted boards converted to walk planks during a rainy time? Who is checking for this sort of waste? Whose pocket is it coming out of? As the wise sayings go, “inspect what you expect” and “waste not, want not”. Check it out – significant savings are waiting to be discovered!
Build to Last, Dave Reichert and the Davis-Hawn Team