Bona R850 Parquet flooring adhesive

Bona R850 Parquet flooring adhesive Hard-elastic

Bona R850 Parquet flooring adhesive Hard-elastic: a true all-rounder parquet adhesive suitable for practically all types of parquet and sub-floors. Resists thrust during wood expansion whilst allowing shrinkage thus relieving tensions on the sub-floor. High initial bonding strength, reducing the potential for “hollow spots”.

Bona R850 is an elastic 1-component silane based adhesive for parquet floors according to EN 14293 (soft). The hardened parquet adhesive is – similar to conventional adhesives – able to withhold thrust during expansion, while the resistance against shrinkage is very low. Tensions to the sub floor are therefore reduced. The use of a primer is in general not necessary. The adhesive hardens by a chemical reaction with moisture.

Characteristics and Advantages:

• one-component, easy to handle;
• soft elastic;
• water and solvent free, nearly no swelling of the wood;
• good adhesion to almost all substrates and timber materials, splashed material can be easy removed;
• firm texture – retains trowel pattern;
• rapid initial bonding strength;
• versatile usage;
• water and solvent free, nearly no swelling of the wood;
• good adhesion to almost all substrates and timber materials;
• RAL UZ 113 Blue Angel for very low emission floor covering adhesives;
• splashed material can be easy removed.

Packaging:

• 15Kg plastic pails;
• 7 Kg plastic pails.

Subfloor preparation:

The substrate must in general be even, totally dry, clean, free from cracks and physically sound. The surface should also be slightly textured. If applicable, it must
meet the requirements of local standards or codes of practice. If necessary it should be professionally prepared for laying. A primer is typically not needed. If the sub floor is problematic the use of a primer like Bona D501, R410, R540 or R580 can improve it. A broadcasting of sand into Bona R410 can be omitted, if the surface stays clean and the parquet is glued with R850 within 24 h. Uneven floors should be levelled with Bona H600, H610 (filling of holes), H660 or H670. Suitable substrates (also in association with under floor heating) are:

• cementitious screed (CT) according to EN 13813;
• floors levelled with levelling compounds (at least 2 mm thick, resistant against plasticizer migration);
• calcium sulfate screed (CA) according to EN 13813;
• plywood, chipboard, OSB board;
• other dry and sound sub floors;
• mastic asphalt screed (AS) according to EN 13813 and other sub floors which are affected by migration of plasticizers must get a protective layer of Bona R410 or Bona R540.

Application method and tools:

Before using the adhesive the following climatic conditions must be met (values for Central Europe):

1. air temperature: min. 18°C;
2. floor temperature: min. 15°C (with underfloor heating max. 20 °C);
3. R.H (relative humidity): max. 70 %.

The parquet adhesive itself must, if necessary, be brought to the right temperature. After opening the bucket remove the protective foil and hardened adhesive at the edges.
The parquet adhesive should be applied evenly using a notched trowel appropriate to the flooring being laid (see below). The parquet should be laid on the adhesive and pressed down firmly during the open time, approx. 40 minutes. If on the sub floor applied adhesive has a skin, remove adhesive and apply new. If some adhesive is pressed up in joints (so that it might come into direct contact with the finish) it must be carefully removed.
Depending on the expected average conditions the parquet needs, for the best adhesion, the correct moisture content of the wood to be selected. Solid wood parquet should be slightly more humid whilst multi-layered or prefinished parquet should be slightly drier. E.g. in Central Europe average room conditions of 20°C and 50% relative air humidity can be expected. Prefinished parquet shall have in average 8%. Typical deviations from the average are +/- 2%. Where doubts exist, avoid too dry material.
Please also refer to the instructions for use provided by the parquet manufacturer.

Consumption and parquet types and tools:

• Mosaic parquet: approximately 850g/m², Bona Trowel 850F or 850G
• 2 layered prefinished parquet: approximately 1000 g/m², Bona Trowel 1000 F or 1000 G
• 22 mm strip flooring, 23 mm industrial parquet, 3 layered prefinished parquet: approximately 1250 g/m², Bona Trowel 1250 F or Bona 1250 G
• 22 mm solid planks: approximately 1500 g/m², Bona Trowel 1500 F or Bona 1500 G

(where F = fine, G = coarse)
Use a fine trowel for small pieces of wood and/or smooth substrates, and a coarse trowel for large pieces of wood and/or less smooth and rough surfaces.

Surface treatement:

Sanding and the application of a surface coating may be carried out after after 12-24 hours. After 24-48 hours it is possible to apply load or stress to the floor. The drying time depends on the type of parquet, the absorbency of the substrate and the climate conditions.