The Problem
Background
Lichen and moss are Mother Nature's first two stages in the attack upon rock, and as far as Mother Nature is concerned your roof is a rock. Lichens often lead the way, creating an environment for algae, moss and later other higher plants. They do not have roots and can grow in locations impossible for other plants such as bare rock, sterile soil, walls, roofs and monuments. Whilst growing they degrade the substrate chemically and physically disrupt the minerals contributing to the process of turning them to dust/soil. In the USA at Mount Rushmore National Memorial, mounting-climbing conservators are employed to continually clean the monument to preserve it from this kind of attack.
Algae and moss form the second stage of the attack. Since the Clean Air Act (1956 and further amended) airborne sulphur, poisonous to moss, has been dramatically reduced, this and a milder climate have contributed to the unprecedented spread of roof moss. Moss rhizoids can penetrate granite and so concrete and clay tiles provide little comparative resistance. Once established they speed up degradation and further assist water penetration of the tile.
Concrete and clay tiles even when new aren't waterproof. Think about it;
when concrete is used as a solid floor inside a house, 4 inches thick,
it is laid on a polythene membrane to stop the damp rising. When concrete
has dried and cures it contains microscopic voids and allows water to pass
through by capillary action. Bricks unless highly compressed when formed
are not waterproof, neither are clay tiles similarly made. Different qualities
of both types of tile exist and some have a design life of only 25 years.
The reason they are used is not because they are good but because they
are cheap and readily available. They replace the scarce and expensive
slates which are waterproof. Most slate roofs even after 100 years look
clean and fresh and don't have the porosity problems of concrete and clay.
Moss and lichen is absent as water and nutrients are not available to sustain
growth. The problem with slates is they hang on the fixing nails, which
corrode, the slates slip and the roof becomes "nail weary".
So why is the lack of waterproofing a problem?
Well,
initially it creates an environment attractive to lichen and moss. Secondly
it causes the physical erosion process. The tile surface becomes wet and
during the winter when it freezes it expands cracking the surface, causes
pits, crazing and spalling, erosion begins. The sand and aggregate eroded
from your tiles washes into your gutters. As the surface degrades, more
water is retained in and on the tile. The salts present in the tiles begin
to dissolve creating additional microscopic voids. Lichen, moss, acid rain,
air borne pollution, bird lime, all accelerates the process. As the moss
becomes established it grows between the tiles and under the laps taking
water directly to the timber beneath. When the moss freezes it expands
pushing the tiles up cracking them. The moss, acidic in nature, bleaches
the surface and further attacks and weakens the chemically alkaline tiles.
The moss flourishes and growth becomes luxuriant. The conditions are ideal,
there is a reservoir of water, nutrients are taken from the tile (more
voids being created) and further fertilised by the birds. 
Even a thin covering
of moss is a problem but worse still a thick covering hides the damage
to the tiles. The weight of the roof covering dramatically increases causing
stress and strain on the structure. Birds and heavy rain dislodge clumps
of moss blocking drains and gutters.
Moss and lichen are a problem, but not the problem; they are a symptom of the greater and more fundamental problem of the degraded, damp and porous tiles.
Eventually the whole tile becomes very porous; water penetrates to the timber under-structure which rots. Tiles become unsafe, unstable, major roof repairs and/or re-roofing is necessary. All this happens long before you see water dripping into your home.
What does the Aquashield total waterproofing and roof renovation system do?
It is a four stage process, but at its simplest
it stabilises and waterproofs the tiles. The water based, micro porous
acrylic coating creates a waterproof but
not a vapour proof barrier. This
allows the tiles and roof structure to breathe and the tiles to fully dry
out. We also do not seal the gaps between the tiles or the laps and this
allows air to circulate preventing condensation forming on the underside.
This is an effective application of a long standing technology. Aquashield
own the sole UK rights to the coating and are therefore the only company
offering this exceptional system and guarantee.
How do we achieve this?
Brick
walls are damp proofed by the pressure injection of a spirit based silicon
product. The water is forced from the brick to be replaced by the compound.
The pressure is necessary as water (damp) and spirits (oil) don't mix.
On a roof it is not possible to pressure inject. Here the dampness of the
tile helps us. Our coating is water based, so when we apply it the molecules
of the compound can migrate through the damp and penetrate deeply into
the tile. It then "dries" and subsequently "cures" to form a microscopic
mesh. This allows the smaller water vapour molecules to pass out through
it; but stops the larger water liquid molecules from re-entering, just
as in high tech breathable waterproof clothing. Becoming part of the tile
it is protected by the concrete and clay matrix and won't flake, peel,
crack or blister. It is flexible, moves with the tile and is UV stable.
As it doesn't sit on the tile the texture and character of the tile and
roof is maintained. The tile is stabilised and erosion ceases. We believe,
because of these characteristics, an Aquashield renovated tile is better
than a new one.
As the pointing and verges are also waterproofed they don't deteriorate, maintenance is minimised, saving you money all around.
No water, no erosion, no rot, no moss, no lichen, GUARANTEED.
Heavy
rain washes bird lime and dirt from the roof which helps to maintain the
look for years. Your gutters stay free of moss, sand and aggregates. Conservatory
roofs, patios and pathways remain cleaner, longer. Unlike other companies
who offer minimal guarantees, we give a 10
year guarantee. Our coating
will not flake, peel, crack or blister and moss or lichen will not re-grow.
Power washing, scraping, brushing and treating with chemicals are very
short term solutions. Chemicals wash away. A power wash without our coating,
accelerates erosion (reducing the productive roof life), leaves a cosmetically
unappealing surface, spreads moss spores and creates a great substrate
for lichen and moss.
Available in five colours, one will ideally suit your home. If it has been extended an Aquashield protected roof has the additional benefit of unifying its appearance, considerably enhancing your home's "kerb appeal", it improves saleability and increases value.
Enhanced 'kerb appeal'. Improved Saleability. Increased Value.
