Two-layer parquet

A two-layer parquet is the type of parquet that contains the visible top layer as the first (upper) layer and the carrier material as the second layer. These two layers are connected to one another with wood glue or a PU hot melt adhesive.

Two-layer parquet is available in a wide variety of dimensions:

1. Single rod: 400-1,000 mm x 70-90 mm x 10-14 mm
2. Two-plank boards: 1000-1400 mm x 120-140 mm x mostly 10 mm
3. Planks: 1000-1400 mm x 120-140 mm x mostly 10 mm

The advantage of this type of parquet is that it is usually laid with a finished surface (i.e. varnished or oiled) and there is no need to process the surface on site. Glued over the entire surface, it is also suitable for underfloor heating. Subsequent renovation is easier than with conventional three-layer prefabricated parquet, which is laid floating, but the useful life of solid parquet is only approximately reached with products with a wear layer of at least 6 mm.

Carrier material

The carrier material for two-layer parquet consists of plywood, softwood or hardwood (mostly oak deciduous wood), depending on the manufacturer's philosophy. This substructure is more important for the longevity of two-layer parquet than the later visible top layer.

1. Plywood: The carrier material for two-layer parquet with the best dimensional stability. The advantage of this process is cheaper production and the inherent rigidity of the parquet strips. Corrugated sheet metal effects cannot occur here, but the various layers of glue in the plywood can peel off. In the production process, after gluing with the top layer, plywood beams are pressed and cut under a hot press. The change in moisture and the build-up of tension in the wood can be disadvantageous in the case of poor productions. The plywood panels must also be sawed to the millimeter. Another disadvantage of no-name products is the multiple layers of glue in the plywood, which can release formaldehyde. The type of wood of the plywood is important, with birch plywood guaranteeing the best dimensional stability.
2. Hardwood lamellas : In this substructure, oak lamellas are usually separated and cold-pressed under the top layer (glued with hot-melt adhesive). This method does not lead to any build-up of tension and the oak itself does not react very strongly to small dampenings from the substrate. However, the lamellas have vertical and horizontal annual rings. In the event of moisture, e.g. B. through the subsurface, these lamellas bowl out differently and on the top layer, in the sidelight, a certain corrugated iron effect can be seen. This disadvantage can only be avoided with products with softwood lamellas with (almost) exclusively standing tree rings.
3. Softwood slats: The production process is the same as hardwood slats, so there is no tension build-up in the product. Depending on the manufacturer, there are now mixed lamellas, i.e. horizontal and vertical annual rings or only vertical annual rings. If the annual rings are only standing, the lamellae swell evenly when moisture is absorbed and no corrugated iron effect is visible.

The closer the standing annual rings are, i. H. the more winter growth and the less summer growth there is, the less there can be swelling and the more stable the substructure. Closely standing tree rings have z. B. spruce wood from Scandinavia, the disadvantage of this wood is the high cost for the producer.