Roof Cleaning and Moss Treatment in Christchurch
Moss, mould and lichen treatment and water blasting for roofs across Christchurch and Canterbury - the first step of every roof we paint, and a service on its own for a roof that does not need painting yet.
Why Moss on a Roof Is Worth Dealing With
Moss and lichen are not just a look. Moss holds water against the roof for days after rain, which is how a metal roof rusts at the laps and a concrete tile roof stays damp and breaks up in a frost. Lichen etches into a coating. Both of them clog the spouting with what they shed. And a roof that is green on the south side and chalky on the north is a roof whose coating has stopped working - which is the point at which cleaning alone, or cleaning and painting, saves you real money later.
South-facing slopes, roofs under trees and anything on the damp side of a Christchurch house get it worst. So do the concrete tile roofs of the 70s and 80s once their surface coating has gone porous.
Treat, or Blast?
There are two ways to deal with a mossy roof and they suit different roofs.
- Moss and mould treatment. A biocide sprayed across the roof and left to work. It kills the moss, mould and lichen, which then dry out and weather away over the following weeks and months. No pressure, so it is gentle on older coatings and on tile roofs, and it keeps working for a good while afterwards. This is the right answer for a roof that is otherwise sound and does not need painting yet.
- Water blasting. High-pressure washing that takes the moss, lichen, dirt and chalk off the roof there and then. This is what we do before a repaint, because the new coating needs a clean, sound surface under it, and it is followed by a treatment so the spores left behind die rather than regrow under the paint. On its own it makes a dramatic difference to how a roof looks in a day.
Corey will tell you which suits your roof. Water blasting a roof whose coating is already failing tends to strip more coating off, which is fine if it is being painted and not what you want if it is not.
Not Just Roofs
The same gear and the same treatments work on the rest of the outside of a house. We water blast driveways, paths, patios and fences, treat mould on exterior walls and soffits, and wash down cladding - often as part of getting a house ready for exterior painting through CM Decorating's main site, and just as often on its own before a sale or a summer.
What Happens
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Corey looks at the roof
How much growth there is, what the coating underneath is like, and whether cleaning alone will do or whether it is really a roof that wants painting. You get a written quote either way.
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Protection
Drop sheets over the garden beds, and care taken with what runs off the roof and where it goes. Downpipes that feed a water tank are disconnected first.
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Treatment or wash
A biocide treatment sprayed over the whole roof and left to work, or a high-pressure wash followed by a treatment - whichever the roof needs.
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Spouting cleared, site tidy
Whatever came off the roof is cleared out of the spouting, the paths are washed down and everything is left as we found it.
Ready to paint as well? Metal roofs, concrete tile and decramastic.
Green Roof? Grey Roof? Both?
Ring Corey. He will come and look, tell you whether it wants treating, blasting or painting, and give you a written price for whichever it is. Free, and no obligation.
Get a free quote
Roof Cleaning Questions
How long does a moss treatment take to work?
The moss and lichen die within a few weeks and then weather off over the following months - it is a slow tidy-up rather than an instant one. If you want the roof clean today, that is a water blast.
Is water blasting safe on my roof?
On sound steel and concrete tile, yes, with the pressure and the technique set for the roof. On a roof whose coating is already failing it will take loose coating with it, which is what we want before painting and not what you want otherwise - so Corey looks first and recommends accordingly.
Do you collect rainwater? Is the treatment safe for the tank?
Tell us before we start. Downpipes feeding a tank are disconnected for the job and for the first good rain afterwards, so nothing from the treatment or the wash ends up in your water.
Can I just clean it instead of painting it?
Often, yes - if the coating underneath the moss is still sound, a clean and a treatment is all it needs and that is what we will recommend. If the coating has chalked out or the tiles have gone porous, cleaning will make it look better for a season and the moss will be back; that roof wants painting.
Other Roofs We Paint
One trade, done properly. Metal, concrete tile and decramastic roofs, prepared and spray coated by the same person who quoted them - anywhere in Christchurch and Canterbury.
Long-Run & Corrugated Iron Roof Painting
Colorsteel, long-run and corrugated iron roofs - washed, rust treated, primed and spray coated in a colour that suits the house, across Christchurch and Canterbury. Read more
Concrete Tile Roof Painting
Faded, mossy concrete tile roofs brought back with a proper clean, a sealer coat and a flexible acrylic membrane that stops the tiles drinking water. Read more
Decramastic Roof Painting
Pressed metal tile roofs from the 70s and 80s, cleaned of loose chip and coated so they look like a roof again instead of a patchwork. Read moreGet a Free Roof Painting Quote in Christchurch
Tell us what sort of roof it is and roughly where the house is. Corey will come out, have a proper look at the roof, and give you a written price with no obligation - anywhere in Christchurch or Canterbury.
022 169 7614- [email protected]
- Christchurch, working across Canterbury
- Monday to Friday, 8am to 5pm
Photos help. If you can, take a couple from the ground or the street and mention them in your message - please do not climb onto the roof to take them.