NATURAL HYDRAULIC LIME


Façade Refurbishment


Old structures rendered with Roman Cement and lime mortars need not necessarily be hacked back to the substrate. The range of bonding mediums available in the Unilit range ensure perfect adhesion and compatibility as a competitive option for façade upgrading. Unilit 10 and Unilit 15 (P1 and P2) in the product guide refer.


Pointing Mortars


The importance of the binding material and its function in the joint of masonry is often overlooked. The bedding joint is the means by which the structure stands up (in all but dry stone walling) but in lime built structures it is also the conduit, which allows the structure to breathe and allow vapours that occur inside the building to migrate outwards. It is also the drainage mechanism that allows any wind driven rain to penetrates in to the external fabric via fissures in the stone or brick. A hydraulic lime mortar in a pointing joint will naturally draw any moisture from the less porous stone and brick and extract it in to the atmosphere to dissipate as a vapour. A cement or synthetic pointing mortar that is less permeable than the masonry will cause moisture to build up at the joint as outlined in the diagrams below.


Unilit Natural Hydraulic Limes contain no resins or synthetic additives that can cause staining to the stone that it is in contact with, it will always remain softer than the medium whose joint it is protecting and allow each element to naturally move without debonding. If cracking of the substrate does occur as a result of building stresses or movement, there is less concern than with synthetic materials as any moisture that penetrates will eventually be extracted by the lime mortars in the surrounding sound areas.


12


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16