**Please consult the guide for your certain floor to ensure which methods are allowed for that brand of engineered hardwood flooring.
Floating: This method you lay the floor down and use tongue and groove glue and glue the tongue to the groove. This method works and is a popular method for homeowners installing their own floors. However, this method is not the most ideal option like nails with glue assist. Another note is to know that not all widths/thicknesses/brands allow this method
Nail Down: In this method, you only use a nail to nail the floor to the ground. The nail will sit right flush with the tongue. You should make sure when using this method you have your air pressure set correctly if the pressure is too high – you will have lots of cracks and squeaks. Remember, in a 3/4″ thick floor this method is fine up to 4″ and a glue assist is absolutely not needed. However, for anything over 5″ and if the floor is less thick than 3/4″ you need to be very careful as it is possible to have more noise on the floor since the nails potentially could not be set correctly. A nail not set correctly could not be holding the floor down to the subfloor correctly. This will produce issues with the floor over time.
Nail & Glue Assist: This is probably the most ideal installation for every engineered hardwood floor out there. Ideally, the nail holds the floor and the glue ensures less noise if a nail is not set correctly. As all machines are man-made, nails can be not perfect, and obviously no matter who the installer is – room for error is great. Using glue is basically insurance you will have a perfect floor outcome. To do this method you either use an S pattern or glue stips with sausage gun glue from Pallmann or Loba. Then you nail the floor down as per the NWFA rules.
Full Glue Down: In this method, you trowel adhesive down on the floor and put the floor down. This is ideal on slab-on-grade or concrete subfloors. You are able to do this on plywood or OSB as well. Just remember if on OSB/plywood if you rip this out your subfloor is most likely ruined and going to cost a lot of money to fix.