Whether you're laying a subfloor, installing siding or laying hardwood or laminate floorboards, you're going to have end joints. The end joint is where one board or plywood sheet butts up against another. In almost every situation, it's important to stagger these joints to avoid straight lines that extend in a perpendicular direction across the lengths of the boards. This is a matter of appearance, but more importantly, it's one of stability. Staggering the joints makes the overall surface stronger and less vulnerable to buckling and gapping. It's best if the stagger is random, especially when you're laying flooring.
The Importance of Staggering
An end joint is an inherently weak spot in a floor or siding installation. Tongue-and-groove or shiplap boards derive strength from their connection to other boards, but the connections at the ends are weaker than those along the sides. If two end joints are adjacent to each other, the placement magnifies the weakness of each joint. By ensuring they have solid connections to the boards on either side, you minimize the "give" on each joint and the tendency to separate.
From an aesthetic standpoint, staggering avoids straight lines that cut across the surface and gives it a grid-like appearance. The stagger pattern should be random because regular stagger patterns can be just as distracting as straight lines.
Staggering a Subfloor
Stability is more important than aesthetics when laying a subfloor, so it isn't important to make the pattern random. When laying the plywood, install a full sheet along one edge of the floor, then start the next row with a half sheet and use a full sheet for the third row. This technique will produce a regular H pattern, which is undesirable for finished flooring but fine for a subfloor.
When it comes to siding, appearance trumps stability. Horizontal siding, whether wood, vinyl or aluminum, looks best if your eye isn't drawn to the joints – and it won't be if the joints are random. Siding boards usually come in uniform lengths, so the best way to achieve a random stagger pattern is to cut the first board of each row a different length before installing it. You can often get great stagger patterns by using the off-cut from a row you just finished to start the next one. If it doesn't work for that row, save it. It will probably work two or three rows later. The average stagger should be no less than 3 inches.
Staggering Hardwood and Laminate Flooring
Flooring installers refer to the process of laying out a hardwood or laminate floor with an eye to color matching and staggering as racking. Proper racking is important both for stability and appearance. Some laminate installers recommend leaving a gap of no less than 12 inches between the end joints of adjacent rows, whereas hardwood installers say it should be three times the board width. Because laminate planks are often 6 inches wide and only 36 inches long, the prescription for hardwood spacing obviously won't work when installing laminate boards.
Two things to avoid when staggering either laminate or hardwood boards are H-joints and steps, or lightning. H-joints occur when the end joints of two boards separated by a single board line up. Try to keep a minimum stagger of about one board width or 3 inches between such joints. A step or lightning pattern is the result of a stagger that progresses by a uniform amount from board to board.
If you're installing random length flooring, you can control the stagger pattern by your choice of boards. Many products come in uniform lengths, however, which makes it more of a challenge to create a random stagger pattern. If the floor dimensions allow, a good technique that minimizes waste is to use the off-cut from the row you just finished to start the next row. If that doesn't create enough of a stagger, and you have to cut a new board to start a row, save the off-cut. You can usually use it at the end of the row.
The need to stagger joints inevitably produces waste. This is one reason why flooring pros always order 10 percent more flooring than they need to cover the floor. By saving off-cuts and reusing them, however, you may be able to reduce that waste to 5 percent or less.