Laminate floors are reasonably easy for a DIY homeowner to install. Laminate flooring is packaged as a number of tongue and groove planks, which can be clicked into one another. Sometimes a glue backing is provided for ease of installation. Installed laminate floors typically “float” over the sub-floor on top of a foam/film underlayment, which provides moisture- and sound-reducing properties. A small (1–10 millimetres (0. 039–0. 394 in)) gap is required between the flooring and any immovable object such as walls, this allows the flooring to expand without being obstructed. Baseboards (skirting boards) can be removed and then reinstalled after laying of the flooring is complete for a neater finish, or the baseboard can be left in place with the flooring butted into it, then small beading trims such as shoe moulding or the larger quarter-round moulding can be fitted to the bottoms of the baseboards. Saw cuts on the planks are usually required at edges and around cupboard and door entrances, but professional installers typically use door jamb undercut saws to cut out a space to a height that allows the flooring to go under the door jamb & casing for a cleaner look.