The subfloor

The front edge of the step has to be straight and match the shape of the profile. Rounded or wavy edges prevent full adhesion of the stairtread at the edge - the area which is subjected to maximum stress. The springiness of the edges at this point may cause damage to the adhesion and the stairtread itself.

Broken-off or non-right-angled edges have to be straightened with repair angles, and levelled. Commercially available levelling compounds or smoothing compounds are used for levelling. Dusty and porous subfloors are primed.

The pre-treatment of subfloor (e.g. grinding, brushing with steel brushes, pre-coating, levelling out etc.) and the tests (e.g hardness, dryness, flatness etc.) follow the technical regula-tions of VOB, Part C, DIN 18 365 "Floorcovering work" and the recommendations of the manufacturers of the precoatings, fillers and adhesives.

At time of installation and of adhesive bonding, the subfloor temperature must be not less than 15 °C. The stair profiles as well as the flooring must have subfloor temperature before installation.

Installation

1. The nora® floorcovering to be installed is glued to the bottom riser element.
2. Measure the angle between the front stair nosing and the wall with a bevel and transfer the measured value to the stair profile using profile strip shears or trapezoidal blade (figure 1).
3. Measure length of the stair nosing and transfer to profile. Measure angle at the opposite wall using the bevel and transfer to profile. Cut to size with profile strip shears or trapezoidal blade (figure 1).
   
   Figure 1
4. Position stair nosing and check for precise fit. Then, the stair nosing can be glued on with neoprene glue. The vertical part is not glued on.
5. Measure area of the tread with stair spider. Transfer measuring points to nora® floorcovering and cut floorcovering to size (figures 2 and 3). Alternatively, templates made of packing paper may used.

Figure 2

Figure 3
6. Glue on the floorcoverings cut to size with neoprene glue or dispersion adhesive.

Provided the installation is performed in a proper and professional way, no joint-sealing of the corners is necessary. If desired, this may be done with 2-component joint sealing compound TH.