Moss, mould and lichen do more than make a property look tired. On paths, steps and concrete, they can create a slippery green film. On painted or porous surfaces, they hold moisture against the material like a damp blanket.
We treat outdoor surfaces across Whangārei and Northland. That includes concrete, driveways, paths, pavers, decks, fences, retaining walls and exterior building surfaces.
The right approach depends on the surface, the amount of growth and how quickly you want to see the result.
Washing removes built-up grime and visible growth straight away. It is often the best starting point when a surface is heavily soiled or you need an immediate visual improvement.
Treatment targets the living moss, mould, lichen and algae. It keeps working after we leave, so the surface changes gradually as weather and time help break down the dead growth.
For many hard surfaces, particularly concrete, the best result comes from washing first and applying treatment afterwards. The wash removes what you can see. The treatment tackles the biological growth that may still be hiding below the surface.
Concrete may look solid, but up close it behaves more like a hard sponge. Its tiny pores can hold moisture and shelter mould and algae spores below the surface.
Water blasting removes the visible dirt and growth. However, small changes in water pressure, nozzle distance and wand angle can affect each pass across the concrete. The spores tucked inside the pores may also survive the wash.
Over the following two to four weeks, moisture and biological regrowth can make the water-blasting passes reappear as dark or green streaks, almost as though someone has drawn lines across the concrete.
That is why Blast Away Guys applies a post-wash treatment. It kills remaining biological growth and continues cleaning after the equipment has been packed away. Over the next three to four weeks, the concrete often becomes lighter and the result visually evens out as the remaining biological residue breaks down.
The treatment is not a concrete sealer and it does not close the pores. It also cannot remove permanent stains, repair damaged concrete or erase natural variations in the surface. What it does is help produce a more even result and keep the concrete cleaner for longer.
For more detail about choosing the right method for driveways, paths and decks, visit our concrete and deck cleaning page.
Not every surface needs to be water blasted. A treatment-only approach can suit areas with lighter organic growth, surfaces where a gradual result is acceptable, or materials that call for a gentler method.
The growth does not disappear the moment treatment is applied. It dies first, then rain, sun and weather gradually loosen and clear it. We will explain the expected timeframe before you decide, so you know what the surface is likely to look like in the days and weeks afterwards.
Outdoor growth thrives where moisture lingers. Shade, overhanging trees, poor airflow, damp winters and Northland’s humid conditions can all help it return. Porous surfaces provide even more tiny hiding places.
Treatment deals with the growth that is present at the time. It can delay regrowth, but no outdoor treatment can stop new spores arriving forever. We will give you an honest recommendation based on the surface and its surroundings.
Roofs need their own assessment. Thick black mould is one of the hardest types of roof growth to treat. It may need a stronger working mixture and two targeted coats during the same visit.
Our supplier has confirmed in writing that our new professional concentrate contains 50% active ingredient in the finished product. We dilute it according to the type and severity of the growth rather than using one recipe for every roof.
For more information about treatment strengths, two-coat treatments and expected clearing times, visit our Northland roof cleaning page. For Auckland properties, visit our Auckland roof cleaning page.
Washing gives an immediate visual improvement. Treatment works gradually. On freshly washed concrete, the post-wash treatment can continue cleaning and visually evening out the surface over the following three to four weeks.
No. New spores are carried by wind and can settle on the surface again. Shade and ongoing moisture also encourage regrowth. Treatment kills the existing biological growth and helps the surface stay cleaner for longer.
No. It is a biological treatment, not a concrete sealer. It kills remaining mould and algae spores and continues breaking down biological residue after washing.
Often, yes. It depends on the surface, the type of growth and whether you want an immediate or gradual result. We will recommend the option that makes sense for your property.
Some smaller areas can be managed yourself with the right product, dilution and safety precautions. Our guide to managing exterior mould explains the basic process.
The duration varies based on the size of the specific areas being cleaned. Bumpy concrete takes a longer than smooth concrete. If the concrete does not have a fall for the water to drain it can also take longer.
The dirtier the concrete the longer it takes. Ditto if the water pressure is not great.
Choose house washing, roof treatments, bug treatments, chimney sweeping and more, all in one coordinated visit. Ask us to price the services separately and together so you can compare the options.
