FAQ's - Roof and Exterior Chemical Softwashing

We often receive questions and enquiries from clients, so to ensure we can make your journey with skyHIGH easier, we have put together the most popular questions and answers below for you. Roof and Exterior Softwashing

skyHIGH Roof and Gutter only use Wet and Forget® Moss, Mould, Lichen and Algae remover in our softwash process. This process removes moss, mould, lichen and algae.

It is not a high-pressure wash and does not remove cobwebs, dirt and grime and other airborne contaminants.


Wet & Forget® Moss, Mould, Lichen, Black Fungi & Algae Remover has a unique combination of biodegradable selective surfactants for moss, mould and lichen removal on absolutely ANY exterior surface.
Wet & Forget® Moss, Mould, Lichen, Black Fungi & Algae Remover is the safest, most effective way of removing these growths.

​When diluted with water and applied, it immediately attacks those unsightly growths such as moss and mould. Each time it rains, this safe, cleansing combination reactivates to help flush away the moss and mould without scouring the surface it has infested.

Some products using other chemicals, notably sodium hypochlorite, may show quicker results initially, but they have no lasting long-term activation properties. Wet and Forget® is designed to provide long-term cleaning action and reactivates again each time it rains.

We recommend that you keep your pets and stock either well away from the wash area or inside your house as applicable until after the area has been well washed down with fresh water.

In the event that they accidentally get into an area that has been chemically washed, it is best to give their paws and backsides a wash with fresh water to be on the safe side.

We also recommend that all pet food bowls are tipped upside down or removed from the wash area.

It is also important to cover any outdoor fish ponds to avoid any spray or wash going into the pond.

Sure can. But you must disconnect the water supply to your tank for at least 4 weeks with a few showers OR have at least 36 mm of rain with colour steel or similar roofs and about 50 mm with tiles and shingles to remove the concentrate and detergents.

We recommend that you consider getting your local plumber in to install some diverters so you can easily stop any treated water from entering your tank. You may wish to check that all water is getting correctly diverted by squirting a water hose down each down pipe and checking that that water is not going into your water tank.

( note that the flip-open style of the downpipe diverter may not be adequate to stop 100% of the chemical wash going through the downpipes. Double check that they are completely open as they may not stop the chemical wash if they are even slightly out of position )

​Please note that the Customer is to open all water diversion systems prior to the roof wash if you are water tank. Skyhigh will not accept any responsibility for any diverters that are not correctly opened prior to the wash.

From time to time we are asked to cut a downpipe ( or we may recommend a downpipe should be cut before doing the wash ) or we may be asked to disconnect downpipes or open diverters in order to divert the chemical wash from your water tanks. Skyhigh accepts no responsibility for any incorrect cut placement or damage due to disconnecting downpipes or incorrect diversion of chemical wash from your roof.

Check that the water coming off your roof is not foaming before you reconnect your water tank intake pipes.

Wet and Forget® has been used for over 35 years to treat biological growth on roofs.

Please note that Skyhigh accepts no responsibility for reconnecting your water tank too early before the chemical detergents have been washed off your roof with rain.​

It is mainly dependent on the intensity of the growth. If it is really light you will see results within days. Otherwise, it may take longer. Your concrete may turn an orange-brown when the Wet & Forget® is applied. This is normal and shows there has been a good reaction. The discoloration will dissipate over a short period of time and is not permanent. The good news is that when applied again the following season, the clean-up will occur within weeks. In the very worst-case scenario where contamination is extreme, it may take 6-12 months.

​We are regularly advised that clients wish to have their roofs cleaned in order to carry out a repaint. A chemical wash is ideal for this as unlike a water blast, it will kill the spores and stop growth from reappearing under the new paint.

​However - you must be patient and let the product work BEFORE you get the paint out.

In our experience, each site is different - some very bad black mould roofs/fences, and soft stone surfaces may need a 2nd treatment a few months after the initial chemical softwash to totally kill the mould. Other places with years of black mould build-up may need a water blast after the mould has been killed in order to clean it up to prep for painting if you can't wait for the dead matter to weather off due to your repaint schedule. ( Skyhigh does not do waterblasting )

​( Note that it is far easier to water blast the dead matter off a roof than trying to blast living mould and lichen off. In some instances, it is impossible to totally remove black mould. )

Other factors that influence how quickly the dead growths disappear are

  • Type of roof surface eg tiles tend to take longer than colour steel
  • Steepness of roof for rain water flow velocity off the roof
  • Angle of house roof to prevailing weather
  • Type of growth - black mould or lichen ?
  • Time of year - amount of rain and heat.
  • Surrounding obstructions to the weather like other buildings and trees etc.​

We can't control these factors but the first step is to kill the growths with our chemical wash then let time do the rest.

On a cool, dry windless day and when no rain is expected for 4-6 hours. We recommend that you wash down outside tiles, timber steps etc after about 5 hours or so as sometimes these can get slippery after application. A simple hose down is all it takes if rain doesn't do the job for you.

Same with windows - you can either hose them the next day to clean off the residue or just let the rain wash them off the product.

You may also notice some spray residue on exterior joinery and weatherboards. This is just the dried surfactants within the wash. This will come off with a bit of weathering, rain and time.

It may be advisable to cover delicate plants close by with plastic or paper just to ensure they don't receive any overspray. Again a hose down after the wash is always a good idea.

​Please be aware that some flowers do not like any chemical wash spray whatsoever and will die off even after a watering down.

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why choose skyHIGH

skyHIGH Roof and Gutter Cleaning uses the best equipment available to provide our service.

​We can inspect gutters with our blue tooth camera system to establish where blockages are and what may be causing them ( eg kids' shoes, balls, bird nests etc ). This allows us to specifically target a known troublesome area for cleaning.

We can also do the cleaning job without the owner having to be on-site given we have our own power supply and are fully self-reliant.

We guarantee our work. Let us know if you are not happy in anyway and we will fix it !

Our customers our service

We are not usually ones to blow our own trumpets, but we are clearly doing something right. Check out the positive reviews we are receiving on Google Reviews below. Our feedback has also been great on No Cowboys. See reviews here.

Eric Nienhuis
Eric Nienhuis
Great service. Good price. Dave was in constant contact as this work is weather dependant…and as soon as he was able, he was onsite early and doing the business. Dave explained in detail how lichen and grunge works, and why water blasting is a no no. Sit back and relax, Auckland’s rain will do the rest. Thanks again for a great job!
sharmila raj
sharmila raj
Dave was extremely professional, on time both to do the quote and coming in for the gutter clean. He dealt with Vector himself, no hassle, very happy with the service received.
amanda abdel-latif
amanda abdel-latif
We had Dave do our Roof and gutters in preparation for selling. The job was outstanding and very professional. Dave is quick to respond and get the job done and turned up when he said he would. We would highly recommend him and his company to anyone.
Martha Meyer-Schlapp
Martha Meyer-Schlapp
I couldn't be happier with the service, very professional, friendly, and explaining all the procedures so I could easily understand them. He did the gutter cleaning und sprayed the roof which ist two stories up.
JustinH Moyle
JustinH Moyle
I passed Dave when I was walking through Howick and noticed his van signage. He offered to drive down to survey my house to unblock the high guttering and submit a quote- which I later accepted. he has all the gear for the high work including Go pro camera- and does an excellent job.
David Clarke
David Clarke
Great service , would recommend them
Nanda MacLaren
Nanda MacLaren
Very happy to recommend this service. Vacuuming out the gutters is the best approach and Dave does it professionally, efficiently and courteously.
Sarah McCulloch
Sarah McCulloch
Highly recommend Skyhigh Roof and Gutter Cleaning! Great communication and really helpful advice on how to improve our current water tank set up, we wouldn't have known we could fairly simply improve our water quality otherwise. Will definitely be using them in the future.
Vivienne Kerr
Vivienne Kerr
Would highly recommend Dave. Excellent communication and a very prompt thorough service. Will use again.