Our Island is a Gem with a history that spans thousands of years. We are surrounded by beautiful churches with many of them constructed during the stay of the Knights Hospitallers of St John of Jerusalem. They are a treasure build by our fathers as a sign of devotion to our lord Jesus Christ.
When were Maltese churches built?
Many were built at the height of the baroque period and are lavishly decorated and enriched with priceless paintings by many famous artists of the time such as Mattia Preti, Caravaggio and Giuseppe Cali. It is impossible not to stare at the ceiling upon entering these places of worship. Every time I walk in a church I always ask myself the same question, what type of waterproofing system is protecting these time capsules? and is there any water infiltrations slowly damaging these masterpieces?. Churches roofs are made of shreds of pottery better known in Maltese as (Deffun).
With what were roofs made off in the olden times?
Before the advent of concrete and iron beams, roofs were made with stone slabs rested directly on wooden beams and covered by a thickness of stone rubble. The surface encrustation to level off the roof and prevent water seepage was usually carried out by women using a solid wood tool known as (Marzebba).
They use to chant songs to keep with the rhythm while they beat the sealer consisting of a mixture of fine dust, pottery fragments and other materials moistened into a cement. The result is a reddish seamless surface that can last for centuries. This solution is very effective however it is vulnerable if the roof is subjected to any movements or when
tampered with for some reason as cracks and holes can easy form.
With what would they repair the roofs?
As time goes by in many occasions we see that the first signs of repairs were carried out with cement and this is bad as these two stubborn materials do not go hand in hand and the result is usually more cracks, detaching of cement and wider openings are re-formed. In these last 60 years someone had the bright idea to cover these type of roofs with the black bitumen carpet membrane. The results were catastrophic. The bitumen melted with the intensive sunrays and penetrated inside the upper crust (deffun) dissolving it completely while the excessive heat created by this bitumen material roasted the wooden beams beneath leading to structural damage and the need to change the roofs.
What can we do to protect church roofs nowadays?
Luckily most of our churches were not subject to this act of atrocity by some self-thought know it all alleged experts. Nowadays thanks to research and properly trained roofers we can safely protect this inheritance which our fathers left us to enjoy and to make sure that it is safely preserved to our children and successive generations.
The method of works is quite elaborate and must be carried out in stages.
Sanding of the surface area to remove moss and other micro organisms.
Sealing of openings and cracks with an elastic UV resistant Polymer.
Implementation of a triangular fillet at corners with a UV resistant elastomer.
Application of a 2 component water based consolidator to strengthen the duffun.
Application of a water based primer with biocide to eliminate all spores and increases the adhesion with the membrane.
Application of a UV resistant elastic resin membrane that is also resistant to stagnation and with a thermal protection of not less than 90%
Implementation of Fibre glass net.
Application of 4 coats a UV resistant elastic resin membrane that is also resistant to stagnation and with a thermal protection of not less than 90%.
The total consumption must be of 2kg per square metre.
Where can these types of roofs be found?
Besides churches and other historic buildings these type of roofs can still be found in old village cores and traditional farm houses. The large amount of rubble they contain inside make it very difficult to detect any water entry. The fact that you do not see the water drooling down your walls that does not mean you are not experiencing water intake.
The trapped moist can stay there for years and can deteriorate the wooden beams. Funny enough, with these types of roofs one can easily observe and get a clear indication of water intake in the dry summer months as the moss and microorganisms can only survive if there is enough water trapped inside to sustain it. A good advice if you opt to have your waterproofing needs carried out by third parties, always make sure they are members of the Malta Professional Waterproofing and Resin Flooring Association. Always demand to see the Association’s INSTALLERS CARD. This will save you a lot hassle as improper roof protection by unaccountable or unethical persons can give way to a serious of unwanted damages.
From where do building damages originate?
Over 80% of building damages originates from water intake. The result is an endless court case if you are lucky enough to trace the guys who carried out your works. All this will eventually take years and prove fruitless.
What can Maltese installers do to improve their workmanship?
The Malta Waterproofing and Resin Flooring Association provide technical knowledge and professional formation to all Maltese installers who wish to improve their workmanship or start a carrier in the waterproofing business. The Association also assists its members by providing the services of a profession advisor when facing challenging situations or other difficulties during their works. The Association also provides its qualified members the Certified Installers Card. This is done to reassure the general public that the person is able to carry out the requested job at its best.
Who made all this possible?
All this is being made possible thanks to the Resin and Membrane Centre and NAICI International Academy. For further information with regards the Malta Professional Waterproofing and Resin Flooring Association visit our website on www.maltawaterproofing.com or call on 27477647.
Written by Antoine Bonello.