Fiberglass self-adhesive mesh tape XJ4590

Where mesh tape is the right answer

Mesh is the fast option for repairs, for board that has already been painted, and for joints where a little movement is expected. It also doubles as render reinforcement and as a carrier for tile adhesive on insulation board.

The one rule is that the joint itself must be filled before the tape goes on. The adhesive holds the mesh to the board, not across a void, and a mesh bridging an empty gap will crack exactly where the gap is.

How to apply it

1. The wall must be clean and dry.
2. Centre the tape over the length of the joint and press it down firmly.
3. Apply a generous first coat of compound over the tape and through the mesh, filling the joint crevice completely; wipe off the excess but leave enough to cover the mesh.
4. Let it dry completely, then sand lightly.
5. Apply thin finishing coats until the surface is smooth.
6. On butt joints — cut board ends with no tapered edge — take extra care that the compound penetrates the whole joint, and expect more edge feathering.

Choosing a weight and a mesh count

For a drywall seam, 8×8 or 9×9 at 60–90 g/m² is the working range: fine enough to disappear under compound, open enough to key. For render reinforcement, insulation board and crack bridging, step up in weight and go to 4×4 or 5×5, where the opening is wide and the load is spread over more strands. The 1000 and 1200 mm widths are the ones used for facade and insulation work; the 25–50 mm widths are for drywall joints.

Failures we see, and why

Almost every mesh complaint comes back to one of three things: the joint was not filled first, the compound was too stiff to press through the mesh, or the tape was applied over dust. A setting-type compound rather than a drying-type one gives the best result, because it does not shrink back out of the openings.