The overlay parquet from Great Britain describes parquet strips with lateral tongue and groove joints, which differ in their thickness (up to 14 mm) from solid wood parquet with tongue and/or groove (thickness from 14 mm). The technical regulations are DIN EN 13228, which also deals with parquet blocks with a tongue-and-groove connection system with different dimensions. The very small tongue-and-groove connection on the overlay parquet and the parquet block only has an alignment function, i.e. it does not take on a load-bearing or load-distributing task. According to this, overlay parquet must always be laid on a continuously load-bearing substrate. Overlay parquet is available both as raw solid wood and with a finished surface.
Wood for overlay parquet must be healthy and its surface must not have cracks. Further specifications regarding the admissibility of e.g. healthy sapwood, knots, shallow cracks, bark ingrowth, lightning cracks, fibre tendencies, resin galls, colour differences and heartwood, in each case depending on the type of wood and the respective classification, can be found in Tables 1 to 6 of DIN EN 13228. The edges of overlay floor elements may be chamfered and have adhesive seams on their underside. In the parquet block, instead of adhesive seams, there is a 0.5-1.5 mm chamfer along the lower longitudinal edges of the block to absorb excess adhesive. The vertical surfaces of each parquet block must be slanted between 0.5 mm and a maximum of 1.5 mm so that the top of the parquet is larger than the underside.
Source: bauwion
