Installation Methods
In general, hardwood floors are installed using one of three methods:

Nail-down: The traditional method for installing hardwood. The installer nails (or staples) each board to the sub-floor, and then nails (or staples) that board into the next board in the line. This process is continued across the entire floor.

Glue-down: Floor boards are glued to the sub-floor using a strong adhesive. This approach is effective as long as the boards are not too thick (generally no more than ¾ inches thick).

Floating: Strips of flooring are glued or snapped together and then laid on top of underlayment. The underlayment serves as a moisture barrier, preventing moisture from seeping back up from the sub-floor into the hardwood, substantially extending the life of the floor. The hardwood floor is held in place by the weight of the floor as well as the base molding around the edge of the room. Because the floor is “floated” over a moisture barrier, it can be installed over many different types of sub floors (unlike solid wood, which requires a very level sub-floor and typically can not be installed over concrete).

Hardwood installed using the floating floor method is the only hardwood floor where the planks are actually “adhered to each other”. Hardwood installed in the traditional nail down or glue down method is actually adhered to the sub-floor. Because the planks are adhered to the sub-floor (rather than to each other), the planks move and separate with changes in temperature, leaving gaps in the floor. Floating floors offer the best resistance against plank separation.

Only dimensionally stable hardwood can be “floated”, which is why solid hardwood and lesser quality engineered hardwoods are nailed down or glued to the sub-floor.

The advantages of the “floating floor” installation method can be summarized as:

• Installed over a moisture barrier, providing additional protection;

• Can be installed below grade and over concrete, unlike most solid hardwood;

• Offers the best resistance against gaps forming between planks, because the planks are adhered to each other rather than to the sub-floor.