Horizontal Vs. Vertical Wall Joints: How To Use Fiberglass Mesh Joint Tape For “Pre‑Cracking Reinforcement”

Horizontal joints (e.g., floor‑level cold joints) are subject mainly to shear forces and inter‑storey movement. The tape should be centred over the joint, with a minimum overlap of 50 mm at each end.

Vertical joints (e.g., between masonry and concrete columns, or at wall intersections) are more affected by thermal shrinkage, which tends to cause continuous vertical cracks. Here, the tape should extend at least 100 mm on each side of the joint to create a "wide‑band" crack‑resistant zone.

① Clean the substrate – Remove dust, grease, and loose particles; ensure the joint is dry, otherwise adhesion will be compromised.
② Lay the tape – Press the tape firmly along the joint, using a squeegee to expel air bubbles and achieve full contact with the base.
③ Cover with plaster – Apply a thin coat of crack‑resistant mortar over the tape. The mesh embeds into the mortar, forming an integrated reinforced layer with the wall.

Fiberglass offers high tensile strength and low elongation, effectively resisting internal stresses from thermal expansion and contraction. Its alkali‑resistant coating protects against the corrosive effects of cement mortar, ensuring a much longer service life than conventional paper joint tape. The pressure‑sensitive adhesive layer also eliminates the need for extra glues – clean, fast, and job‑site friendly.