The subflooring of a double wide trailer may not be sturdy enough for hardwood floors, and may have an impact on the type of installation method you can use. If the subfloor is made of particleboard or oriented strandboard, or OSB, which is common, a thin sheet of plywood underlayment can be placed on top to provide a better surface for the hardwood. Other choices include removing the original subfloor and replacing it with a better grade of plywood.
If you plan to transport your doublewide home at a later date, the hardwood floors may be affected. The jostling that occurs during transportation can break or warp the flooring. If you have no plans to move the home, the flooring will be fine. Just keep in mind that you may end up with some damaged floor boards if you ever decide to move the trailer.
If you have plywood subfloors, or if you use a plywood underlayment, you can nail the floor down. For particleboard or OSB boards, however, a glue-down installation method is the most appropriate solution. A floating hardwood floor is by far the easiest installation method for a double wide flooring system, but you must purchase tongue and groove flooring for this method to work. If you have problems with adhesive odors, the floating method is also appropriate for thinner subfloors.
Look for a durable hardwood such as oak or cedar if you plan to move your trailer home at a later date. Otherwise, pine flooring is an economical alternative. Engineered hardwood floors are also a suitable alternative flooring for mobile homes. Laminate flooring, while not made entirely of hardwood, is another choice if you do plan to transport the home later, simply because it will cost less to replace any broken or warped boards.