1. Brick problems Dr S Pavia Dept of Civil Engineering TCD

2. Cracking caused by rapid heating or cooling. Defective pointing Brick suction rate determines the effectiveness of the bond between mortar and brick. A smoothed vitreous surface will have a lesser bonding capacity.

3. Aggressive blasting causing entire loss of superficial material or fire skin.

4. Iveagh buildings near Christchurch Cathedral Clay brick: Material loss by abrasive blasting.

5. Material loss by abrasive blasting.

6. Kiss marks dark areas produced on faces of bricks which were in contact during firing. The exposed areas of the brick will be oxidised in the kiln atmosphere during firing whereas the contact faces will experience reduction. Lime-popping or lime-blowing, generated due to expansion induced by hydration of lime particles (limestone fragments in the raw clay would have become lime during firing, when exposed outdoor this lime takes water –slakes- expanding and fracturing the brick).

7. Scum forms on the brick surface by deposition of sulphur dioxide which originates from sulphur in the raw clay or the kiln fuel.

8. Black core in a Dublin brick dating from 1780, made with boulder clay and probably clamp fired: ware in contact with fuel (reducing atmosphere, lack of O2 thus no oxidation of C and S within the clay) or insufficient firing time for organic material within the clay (C, S) to burn out (mix with O2).

9. Presence of cinders, added to the raw clay as a fuel to assist firing.

10. efflorescence

11. St Patrick’s Cathedral Memorial Material sulphation resulting from atmospheric pollution Trinity College. Portland stone

12. Identify causes of decay: a retaining wall, as a result, additional moisture travels through the porous brick. weak porous brick -underfiring materials later introduced in the memorial may be sources of salt. combined action of moisture and salt acting on weak brick has produced material loss and alveolar erosion.