As the trend toward wide plank flooring continues, you as a builder will want to understand the difficulties it presents (see Part 1). Perhaps even more importantly, you’ll want to learn how you can install these floors to help you achieve the highest degree of stability possible, considering the unique needs of these specialty sized boards.
Joinery Considerations for Wide Planks
Typically, flooring boards can be joined by either ship lap or tongue and groove joinery. However, wide planks respond better with tongue and groove, because each groove acts to keep the tongue of an adjacent board from lifting up which, in turn, increases the evenness of the entire floor. The joint can be modified to allow movement while retaining stability across the floor. With careful drying, sawing, and milling, you’ll be well on your way, but without proper installation, even the most expertly selected and milled boards can prove disastrous.
Installation Planning Considerations for Wide Planks
All lumber needs room to move, and while interior flooring won’t fluctuate as much as exterior decking does, wide planks will undergo more significant movement than standard-width planks. In order to prevent problematic amounts of movement, you’ll want to allow time for proper acclimatization once the lumber arrives at the job site. As a necessary part of the lumber drying process, acclimatization at the installation site will give your lumber a chance to come into an equilibrium with its immediate environment — namely, the room in which the boards will be installed. Ideally, the planks should all be stickered to allow for consistent air flow on all four sides of each board.
How much time you should allow for acclimatization depends on how far the flooring has come and how different the moisture levels were in the lumber yard from which it has been shipped. (If you’re not sure about your particular situation, we highly recommend consulting your supplier directly for advice regarding the necessary time period.) As you plan for installation, you’ll also want to take into consideration the sub floor. Depending on the material used, you’ll need to employ the proper techniques to fasten the boards while controlling moisture.
Installation Precautions for Wide Planks
You’ll find that in using the tongue and groove joinery, you allow for movement across the width of the boards, as long as you leave enough of a gap. (The time of year during which you install the floor will determine how much of a gap you leave.) On that note, you want to be sure to communicate with your customer about the necessity of a gap and the fact that it will open up during dry seasons and close up during times of higher moisture.
You can read more about installation recommendations for wide plank flooring in Part 3.