S.A.F.E.R. System Explained

The Sustainable And Safe Way To Clean Historic Buildings

Preserve The Past, Protect The Future: The S.A.F.E.R. System

Safe. Affordable. Fast. Environmentally Responsible.

This encompasses all that Hennessy-Ward stands for.

Scaffold-free façade cleaning means greatly reduced health & safety risks for everyone.
Our specialist biocides do not damage your building.
Low pressure application techniques ensure even the most delicate surfaces stay intact.

Rapid delivery means we can complete most jobs within 1 to 3 days, greatly reducing man hours.
Nature will continue the cleaning process, this is FREE!!
Expensive and potentially dangerous scaffolding is eliminated

Rapid, low pressure delivery of our specialist biocide with precision and care.
No long-term disruption, obstacles, or inconvenience.
We work with your schedule. The treatment can be undertaken on a weekend or outside office hours.

Environmentally Responsible:
We have 100% organic and biodegradable biocides.
Very low water usage is achieved with our precision techniques.
Noise pollution is kept to a minimum with the use of telescopic poles whenever possible.

The Hennessy-Ward S.A.F.E.R. System provides the least disruption of any cleaning service.

To understand the solution, it is important to first understand the problem.

At the heart of our S.A.F.E.R. System is a clear understanding of the problem.

The unsightly staining on your building is caused by a group of plants, collectively called biomass. The biomass started growing on the walls before the building was even finished! At the base of all the organisms that cause the staining is algae.

green algae 1

Algae, along with fungi, lichen and a myriad of micro-organisms cause biodeterioration of stone, slate and external substrates. This causes physical and chemical damage to the façades of buildings and monuments.

The damage they cause depends on the substrate, but in brief they uptake minerals and they produce acid. This can cause the surface of the façade to become pitted and in severe cases to crumble or flake away.

Moss absorbs moisture, keeping roofs wet and heavier for long periods of time. The freeze-thaw cycle can crack slates and weaken the integrity of the roof. This can lead to water ingress and rotting of wooden trusses.

Preventative, preservative, protective maintenance is necessary to avoid costly repairs on our heritage buildings.

Church Before
200 Years of Biomass Growth

When algae and fungus combine, they can form lichens which are typically the bright yellow or green crusty growths seen on ridge tiles or clinging to walls. The two organisms live in harmony (symbiosis). The algae makes sugar by photosynthesis and the fungus provides shelter and nutrients. The lichen produces weak acids that dissolve the surface and releases nutrients for the whole lichen to utilise. These acids etch the surface of the stone giving the lichen a very secure foothold onto the building. Considerable force is required if they are to be removed by mechanical methods.

The biocide that we use is a unique combination of compounds that has been developed to specifically target algae. The solution is non caustic and pH neutral so it will not damage delicate limestone.

8 Weeks After Treatment

When mixed with water in precise concentrations our biocide is attracted to the cell walls of the algae causing them to rupture and die. In doing so the active ingredient is neutralised and thus will not harm anything else. Once killed, the algae will dry out and the dead cells etc will be removed by the wind and rain. This is not an instantaneous process and it can take several seasons for the staining, especially the black melanin, to fully disappear.

Over time the building will get cleaner and cleaner and you will notice the walls getting back to their original colour.

Pebbledash Before
Pebbledash After

The black staining on the footpaths is from a fungus. The black colour is called melanin – exactly the same substance that produces a suntan in human skin. It protects the fungus from the sun’s harmful ultra-violet rays. Fungus usually thrives in areas of increased dampness. The red on the walls is algae.

There is a multitude of different types of moss but they all have one thing in common. They all live synergistically with algae. When we target and kill the algae the moss will no longer be able to survive.

Please note that during the application process and for a short time after, the discolouration will look much worse. This is due to the pigmentation (carotene) inside the algae being released and proves the product is working. The colour can be observed running down the walls or gutters and is totally biodegradable. This staining will quickly fade in sunlight and the debris from the algae will be washed or blown away in the wind and rain.

The black discolouration produced by fungus has to oxidise before it becomes water soluble and is washed away. This is a natural process that can take several months. The dark black stain will slowly change to light grey and eventually fully disappear.

By killing the algae, we cut off the lichen’s food supply and the whole lichen dies. This process obviously takes longer and it may be several months for the lichens to be weathered away.

Remember, they took years to establish and have etched themselves into the surface.

The exterior of this church was covered in black fungus and lichen, especially the areas that remain damper for longer like the buttresses and ledges.

Church Before After

It cannot be stressed enough that the methods and materials that Red Gable Cleaning Ltd use do no harm whatsoever to the fabric of the building.

We are trusted and respected leaders in our field because we use the best methods and the best materials.

We do not use power washing.

We do not use bleach or any other harmful chemical.

Results of Specialist Biocide Softwash

The use of any aggressive method to remove layers of fungus and biomass will result in damage, no matter how gently it is done. Our specialist Biocide Softwash System will do no damage to even the most delicate of surfaces.
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