A non-destructive method for fixing placards with masonry structures

Abstract

It is common practice for government agencies to fix signs – and indeed even official temporary notices – onto masonry structures using steel nails. This method of fixing is destructive; it causes irreversible damage to the material fabric, which has a bearing on the overall aesthetic of the building, a scenario which is more acute if the site is of cultural heritage significance. Stones and concrete blocks (locally referred to as concrete bricks), the latter introduced in the 1950s, are the main materials used in masonry construction in Malta. Clay bricks are not utilized, as in Malta there is a blanket prohibition on the extraction of local clay. The main building material used in Malta since time immemorial is Lower Globigerina Limestone. This article puts forward the case for a non-destructive, reversable method to fix notices to building which respects the integrity of the dimension stones. Instead of being hammered into masonry blocks, the proposed removable plugs are installed in the mortar. Their size is relative to the thickness of the mortar bed and the load they are designed to carry, the latter being of negligible importance in the case of lightweight placards. The proposed solution applies equally to other masonry structures, whether erected in dimension or randomly placed stones, concrete blocks or clay bricks, as long as the construction in question uses mortar in the joints between the units.