F’hiex jikkonsisti l- proċess ta’ qabel jibdew ix- xogħolijiet ta’ restawr fuq faċċata antika?
1. Permezz ta’ perit, isiru pjanti tal-faċċati flimkien man- notamenti tal-ħsarat. Dal- proċess jissejjah ‘mapping’;
2. Separatament minn dawn il-pjanti isir rapport tekniku (‘restoration method statement’) li jikkontjeni proposti dettaljati tax-xogħol u l-interventi li hemm bżonn;
3. Dawn id-dokumenti jintbagħtu lill- Planning Authority flimkien mal- inkartament ta’ l-applikazzjoni bil- għan li jinħareġ il-permess għal dan ix-xogħol;
4. Ladarba jinħareġ il- permess, ix-xogħol irid isir skont il- kundizzjonijiet ta’ dak il- permess taħt is-sorveljanza tal- perit.
Liema huma r-raġunijiet li ħafna drabi jikkawżaw ħsara lill- ġebla?
Dawn huma wħud mir-raġunijiet komuni:
1. Nuqqas ta' manutenzjoni matul il-mijiet ta' snin li l- binja tkun ilha mibnija;
2. Tmermir tal-ġebla jiġi kkawżat ukoll mill-kisi tas-siment li xi drabi jkun sar bħala zokklatura. Dan iġiegħel l-umdita’ titla' aktar ‘il fuq u tiekol il-fili;
3. Tmermir u titqib tal-ġebla (jissejjah ‘alveolar weathering’) ikkawżat mill-effett ta' l- irjieħat li jħabbtu mal-faċċata flimkien mal-proċess ta' tixrib u nxif (‘wetting/drying’) .
4. Depożitu fuq il-ġebla li jikkawżalha ħsara magħruf bħala black crust jew ġmied iswed. Il-ġmied jifforma skorċa ħoxna, li maż-żmien tibda titqaxxar u twaqqa' l- ġebel magħha
Issa, jekk dan il-proċess ma jitwaqqafx, il-ġebla tibqa' tittiekel sakemm tisparixxi (‘erosion’)
{sliderX’ jistgħu ikunu r-raġunijiet wara l- fatt li l- ħsara tvarja minn faċċata għal oħra?}
Ħafna drabi l- ħsara tvarja minn faċċata għal-oħra minħabba l-orjentazzjoni tal- istess faċċata.
How would you suggest to treat/repair an old masonry wall with open joints?
STEP 1: Existing pointing to all joints should be raked out to a depth of not less than 15mm. Where joints are defective to a greater depth, then all loose mortar is to be removed, irrespective of depth. This should be done by small mason hand tools, including small hacksaw blades and narrow screwdrivers. Special attention should be taken not to damage any architectural features.
STEP 2: Once the raking is complete the joints should be flushed with clean water to remove all loose material ready for pointing.
STEP 3: One of the following mixes are recommended for the pointing:
i) 1 part hydraulic lime + 3 parts sand with stone dust as colour additive
ii) 1 part slaked lime + 3 parts sand with the addition of stone dust
iii) 1 part slaked lime + 1 part pozzolana + 3 parts sand with an addition of stone dust
The pointing should be then completed by introducing the mortar to the joints using mason trowels. The joints should be filled with mortar to ensure that no voids are left within any one section of the pointing works.
Where joints are deeper than 20mm the mortar should be applied in two separate operations, one to back out the joint and the other to complete the point to a smooth stone finish.
How would you treat/finish exposed old stonework?
STEP 1: Apply a lime wash with fine stone dust additive to obtain a semi-transparent stone colour. This lime wash, besides having always been an inherent part of the character of typical Maltese facades, will act as a sacrificial layer to the stonework and deteriorate preferentially.
STEP 2: A protective coating should finally be applied to the stone surface. A transparent silicone-based water-repellent coating, which will allow the stone to transpire, is recommended. It is important to ensure that, prior to the application of this water-repellent, the facade has been allowed to dry completely. Two layers of protective coating should be given. This should be applied generously using a brush and should on no account be diluted with thinner. The work should proceed from the top downwards. Between each coat, a minimum period of six hours should be allowed.
