Granite adhesive for vertical surfaces
Adhesive for adhering granite and other natural stone types to vertical surfaces requires specialized construction materials due to the main three challenges in utilizing natural stone on a vertical surface; sagging, sliding and weak adhesion. Most adhesive products designed for general wall use are typically low in viscosity and lack anti-slip features. As opposed to standard wall tile adhesives, which are formulated with a low viscosity of no more than 4,000 mPa and typically slide or sag due to gravity during construction, professional grade vertical granite adhesives are formulated using thixotropic (non-sag) formulas resulting in the stability of paste (the adhesive) on vertical surfaces (walls, facades, overhead areas) not changing. Additionally, the weight of natural granite as well as the amount of moisture absorbed by granite (also referred to as water-absorption) requires the vertical granite adhesive to provide a strong long-term bond to the granite slabs used in a vertical application.
The construction industry offers two types of vertical granite adhesives that cover a variety of engineering applications. The first type of vertical granite adhesive is cement-based (polymer-modified) granite adhesive products that meet the EN 12004 C2TE S1 industry standards. Typical characteristics of this product include flexibility, withstands weather effects, waterproof, and durability characteristics that make them convenient for use in vertical granite wall paving indoors and outdoors. Such adhesives are designed so when structurally micro-deformed (due to thermal expansion/contraction of granite) and/or an application becomes moist due to exterior weather conditions, that their cohesive nature will resist any cracking or hollowing issues causing the granite slab to separate from either the wall or the other granite slabs attached to it. Therefore, these types of adhesives are commonly used in civil (building) building facades and interior wall decorative applications.
The second type of vertical granite adhesive is epoxy and/or polyester knife grade adhesives which are designed for high-strength vertical bonding, filling gaps, and providing local repairs. Epoxy or polyester adhesives are high viscosity (apply like putty), non-drip adhesive products that eliminate the use of complicated clamping type tools during construction as they will not slide or sag while in use. Additionally, epoxy or polyester adhesives deliver ultra-strong tensile and shear bond strengths making them the glue of choice when installing granite slabs on vertical applications larger than the size of a normal granite slab, or when using them to bond/repair granite corners, vertical joints or granite decorative architectural model parts.
Standardization will play a significant role in achieving a successful bonding effect when applying vertical granite adhesives. Before applying vertical granite adhesives, the vertical base surface needs to be flat, dry, free of dust, solid and in most cases, also free of oils and any other loose layers that may prevent the adhesive from performing its intended purposes. Adhesives must be applied uniformly to both the vertical base surface and to the back of the granite with trowels in order to establish full contact between the two materials once they are placed together. In order to maximize the vertical load bearing stability and limit the risk of the granite slabs falling, it is recommended to use a combination of adhesive bonding and mechanical fastening when installing heavy weight granite slabs.
From the aspect of performance advantages, a qualified vertical granite adhesive has better anti-slip capabilities than non-qualified adhesives, is fast curing and provides better aging resistance when compared to non-qualified adhesives. They will also withstand varying weather conditions without becoming discolored, peeling or losing adhesion after prolonged periods of use, thus, meeting durability requirements for use in decorative vertical stone installations. Selecting an appropriate vertical specialized granite adhesive is critical for maintaining the construction quality, safety and service life of granite vertical engineering applications.
