Delayed or Incomplete Curing of Adhesive

Description

This is when flooring elements move horizontally within the first few days or weeks after the installation process. The result may be that gaps start to appear. This is often if heavy objects are moved on the flooring indicating that adhesive has not fully cured.

Causes

Curing times vary between different adhesive types and brands. Various circumstances can lead to extended curing time. These include:

• Covering floors with protective polythene, underlay or sheet materials just to name a few examples.
• Application of finishes on unfinished flooring before adhesive has cured.
• Conditions of high humidity and a low temperature.
• Conditions of excessive moisture in combination with the presence of alkaline salts can cause SBR adhesives to re-emulsify.

There has been some anecdotal evidence that suggests that the curing of moisture-curing adhesives may be affected by the following:

• The application of finishes on unfinished flooring before the adhesive has cured.
• Installing wood flooring that has a finish on the underside.
• Conditions of low humidity.
• Rapid placement of the flooring element onto an adhesive.

Whilst it is unlikely that any one of these factors alone will cause a problem, a combination of the above may lead to very delayed or incomplete curing process. Some manufacturers of moisture-curing adhesives recommend bonding directly to the epoxy DPM's whilst others may recommend screeding over the DPM prior to the application of adhesive.

Solutions

• Uncover the flooring if covered.
• Ensure that the Temperature and RH are suitable.
• Use of heating, and humidifier / dehumidifier where necessary.

Avoidance

• Where applicable, be sure to correctly mix all adhesive components..
• Ensure that conditions are both suitable and ambient.
• Do not apply a finish prior to the curing of an adhesive.
• Do not cover the floor until the adhesive has cured.