Bona R850 Adhesive

Bona R850 Adhesive is perfect for the installation of engineered planks and other types of wooden flooring. The adhesive hardens by a chemical reaction with moisture and is able to resist against movement of wood during expansion. It causes practically no swelling of the wood as it's water and solvent free. Suitable substrates (also in association with under floor heating) are:

• Cementitious screed
• Floors levelled with levelling compounds (at least 2mm thick) (resistant against plasticiser migration)
• Calcium sulfate screed
• Chipboard
• Other dry and sound sub-floors

Please note: Mastic Asphalt screed (AS) and other sub floors affected by migration of plasticisers will require protection using a damp proof membrane (DPM), see Bona R410 DPM and Bona R540.

• For an adhesive for parquet, with more elasticity, try Bona R848 Adhesive
• For an adhesive with ultimate strength, use Bona Titan
• For a flexible adhesive for use on wooden stairs, skirting and door threshholds- Bona R880 Adhesive

The substrate must be structurally sound, clean, dry and free from surface dust, dirt and debris. The surface should be slightly textured for best adhesion. Substrates may need to meet the requirements of local standards and codes of practice before floors are laid. It may be necessary for substrates to be professionally prepared for laying.

• Remove all existing traces of adhesive residue, paint, concrete curing compounds or other contaminants that may affect the adhesive bond
• Sandblasting, shot blasting or scarifying may be necessary to completely remove some of these residues
• Surface cracks, grooves, depressions, control joints or other non-moving joints, and other irregularities must be filled or smoothed with a Portland Cement-based patching and levelling compound

Please Note: Wood flooring must not be installed before the compound has fully cured. Do not install over expansion joints or other moving joints in a concrete slab.

Always do a test area before starting any project to check suitability and compatibility, following the manufacturer's instructions on the container at all times.

Before use, ensure the air temperature is above 18°C, the floor temperature is above 15°C (with under floor heating max 20°C) and the relative humidity is less than 70%. The adhesive itself must, if necessary, be brought to the right temperature.

1. Once opened, remove the protective foil and hardened adhesive from around the edges
2. The adhesive should be applied evenly using a notched trowel appropriate to the flooring being laid
3. Once applied, if the adhesive has formed a skin, remove the adhesive and re-apply
4. Do not allow more than 40 minutes of open time before firmly setting flooring into the adhesive. Higher humidity can decrease open time
5. If some adhesive is pressed up in joints, so that it might come into direct contact with the finish, it must be carefully removed, as there is a danger of migration of plasticisers in the finish film

Coverage Guide

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 (F = fine, G = coarse) Bona Adhesive Trowel

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

The adhesive consumption during the application with the Bona OptiSpread system depends mainly on the walking speed as well as the adjusted air pressure (OptiSpread 100, OptiSpread 2.0). Please refer to respective machine manual.

For full application and coverage details, please refer to the 'Technical Information' Datasheet link above.

It is possible to apply load and stress to the floor after approximately 24 to 48 hours. Any sanding and surface coating to be applied, may be carried out after 1 to 4 days depending on the type of parquet, absorbency of the substrate and room climate.

Q. What is the difference between Bona R850 and Bona R848?

A. The R850 provides a higher spec and shear strength compared to Bona R848. The Bona R848 is more flexible and designed for installing parquet flooring or narrow, solid boards (less than 190mm width) and can be used on both wood and concrete substrates. Bona R850 can be used for solid, engineered wooden floors and nearly all sub floors.