Bona sells into 90 different countries across the globe so we see a wide range of different approaches to controlling moisture in subfloors, be they concrete slab, floated screed or finished with leveling compound. Bona's silane adhesives solve the moisture barrier problem.

In countries such as Germany with strict building regulations, detailed measurement of the floors moisture content is carried out prior to installation, whereas in countries like Australia things are a little more relaxed, with contractors deciding on steps to take based on their knowledge of the building’s condition and the state of the subfloor. It is the contractor’s responsibility to assess the site & make decisions based on that assessment. The days of relying upon a builder’s word that the floor is ‘dry’ are long gone.

So when is a moisture barrier required? A moisture barrier’s function is to reduce or slow vapour transmission, not to fully block vapour movement. A moisture barrier controls existing residual moisture rather than preventing damage from issues such as leaking pipes and spillage (although they can help to minimise damage). Surface coatings are not equivalent to a dedicated physical structural membrane (DPM) that can control water pressure & movement of ground water etc.

Bona’s cutting edge silane-based adhesives bring huge advancements to surface coatings and now can be used as an effective combined moisture barrier.

Bona Silane Adhesives:

• Effective on wide range of substrates including concrete, ceramic tiles and metal.
• High tolerance to temperature and humidity.
• Free from solvent, safer to use and contain no hazardous chemicals.
• Excellent ‘green grab’ with almost immediate hold to the subfloor, reducing the possibility of hollow spots and movement.
• Quick curing - sand after 12 hours and walk on after 4 - 6 hours.
• Acoustic properties - noise transfer is significantly reduced by up to 10dB.
• Easy clean up - unlike polyurethane adhesives silane adhesives are easily removed from hands and prefinished surfaces.
• Low odour - put floor back into use with no lingering solvent odours.

Whilst these qualities give Bona Silane Adhesives a clear advantage in installation, performance and ease of use, the features combined mean that when applied correctly Bona Silane Adhesives also function as a Moisture Barrier, removing the need to use a separate moisture barrier.

Using Bona silane-based adhesive as a combined moisture barrier is a simple, fast installation with few steps; simply select the Bona adhesive suitable for the moisture level in the subfloor, and apply in a thick layer to ensure the whole subfloor surface is covered and there are no gaps between the ribs. It is important that application is carried out correctly to ensure the thickness of adhesive is maintained across the whole floor including the edges where expansion gaps are present. The flooring needs to be firmly pressed down to spread the adhesive from the ‘ribs’ formed by trowel notches and prevent any areas from remaining uncovered.

The benefits of Bona silane adhesives for both contractors and their customers are significant with faster curing, stronger green grab, superior early tensile strength, less hollow spots and acoustic properties. Using Bona Adhesives as a combined system of adhesive AND moisture barrier adds yet another advantage that truly sets Bona apart.