Frames, tracks and weep holes
Window Frame and Sill Moss Removal in Nanaimo
The moss that harms a window grows in the frame, not on the glass: along the sill, down the sliding track and inside the little drain slots that let water out.
Customer reviews
What customers say
Great experience working with this company! Quick turn around time and very professional. I’ll definitely be using their services again in the future.
Great job and fair pricing! Will hire again!
The service provided by the owners of the company and the staff were beyond exceptional. The price was also very exceptable and affordable.
Why us
Why customers love our service
And why you will get the best moss removal service in Nanaimo!
Fast and efficient moss removal
We turn up on the day we said, clear the whole roof, and get off your property without stretching the job out.
Clear and quick communication
You get an answer when you call or text, a price before we start, and a straight account of what we found up on the roof.
Five-star reviews
Consistent five-star reviews from the homeowners our crew works for.
Clearing moss since 2021
Asphalt shingle, cedar shake, tile and metal roofs, and the driveways and paths below them.
- A look at every window from outside, upper floors included
- Moss and grit lifted out of sills, corners and exterior stops by hand
- Sliding window and patio door tracks brushed and wiped out
- Each weep hole cleared and checked with a splash of water
- No pressure washer pointed at a frame, a seal or the glass edge
- Soft wood, lifting paint and fogged panes pointed out to you
- Debris bagged and taken away, sills and decks below swept
Ask most people where window moss grows and they point at the glass. Glass is the one part of a window that stays fairly clean, because it is smooth, it sheds water and every rain rinses it. The moss that causes damage sits a few centimetres lower, in the frame. It packs into the outside sill, fills the joints between frame and trim, grows along the track a sliding window runs in, and blocks the drain slots along the bottom edge. Those spots are narrow, shaded by the frame itself, and always holding a little grit and damp. On a north wall in Nanaimo they barely dry out between fall and spring.
Why the weep holes matter most
No window keeps every drop of water out of its frame, and none is designed to. Rain driven against the glass works past the outer seal and runs into a channel along the bottom of the frame. From there it is supposed to leave through weep holes: small slots, often with a hinged flap, on the outside face of the bottom rail.
Moss is very good at plugging them. A weep hole is a small, dark opening that rarely dries, exactly what a moss spore needs, and fir needles, dust and old spider web give the moss something to hold onto. Once the slots are closed, rain that gets into the frame stays there. On this part of the island the wet season runs roughly from October into March, so a blocked frame can sit with water in its bottom channel for five months at a stretch.
What standing water does to the frame
The damage depends on what the window is made of, and around Nanaimo you see all three common types on the same street.
Older houses in neighbourhoods like Harewood and the Old City often still have wood frames, or wood sills under newer inserts. Wood that stays wet loses its paint first, then softens at the bottom corners and along the sill nose. If a screwdriver tip pushes into the sill, it has moved past cleaning and needs a carpenter.
Vinyl is what most newer or re-windowed houses have. It does not rot, but the frame has hollow chambers, and water held in the bottom one works at the edge seal of the double-glazed unit. When that seal goes, the panes fog on the inside and the glass unit has to be replaced.
Aluminum frames, common on older houses and patio doors, cope with water better but run with condensation inside through the cold months. That condensation drains into the same channel the moss has already blocked, the sliding parts gum up, and a door that once glided now takes two hands.
Where we find it around Nanaimo
The windows that grow the most are the ones that never get afternoon sun or a breeze. On the slopes below Mount Benson and in the wooded pockets of Departure Bay, houses sit under tall Douglas fir, western red cedar and bigleaf maple, and the windows facing the trees stay shaded most of the year. Ground-floor windows behind a laurel hedge or a rhododendron are another favourite, as are the windows under a carport roof or a deep second-floor deck. Townhouse and strata complexes often have a whole north-facing row of identical frames all going green at the same rate.
Much of the city sits in the Coastal Douglas-fir zone: mild, damp winters with long spells where the temperature hovers above freezing and nothing dries. That is ideal weather for moss in any narrow, sheltered gap, and a window frame is full of them.
How it works
How we clear a window frame
A house with twenty windows is still done one frame at a time. Shaded sides of the house are where we spend longest, since the growth there is thickest.
Walk the outside
We go round every side of the house noting frame material, which windows face north, which sit under a deep eave or a big tree, and which sills already look soft or stained.
Pick out the growth
Moss comes out of corners, sill edges and tracks with small brushes, plastic picks and scrapers shaped to the profile. Water is used sparingly and only at low pressure.
Open each weep hole
Every drain slot is cleared through from the outside, then we pour a little water into the bottom channel and watch it run out. A slot that looks clear at the face can still be packed inside.
Wipe down and report
Tracks and sills are wiped clean so loose grit does not end up under a sash or against a seal, and you hear which frames are sound and which ones want a closer look.
That's it.
- You tell us about the roof.
- We give you a clear quote.
- We take the moss off.
- You get one less chore to worry about.
Ready to get the moss off your roof? Get your quote and let us do the climbing.
Hand tools, very little water
Frame work is slow, detailed and done by hand. We lift the moss out with brushes, plastic picks and scrapers sized to the track or sill profile, then clear each weep hole and test it with water. We use a sprayer or a damp cloth to rinse, not a hose aimed at the wall, and we never bring a pressure washer anywhere near a window. Where a sealed unit already looks fogged or the wood is soft, we go lighter still and tell you what we saw.
Upper-floor windows are reached from a ladder set on firm ground, the same way we reach the eaves. If a window is over a sunroom roof or a steep bank and cannot be reached safely, we say so at the quote rather than on the day.
Fitting it in with other work
Few people book window frames on their own. The usual pattern is to add them to a roof visit, since the shaded side growing moss on the shingles is nearly always the side growing it on the sills too. If the growth keeps coming back fast, our moss treatment and prevention page covers trimming branches back and timing a follow-up.
We clear window frames across Nanaimo and the nearby towns, including Lantzville and Ladysmith. Tell us roughly how many windows there are, which ones are upstairs and whether any sliding doors stick, and ask for a free quote.
Why choose us
Why choose us for window moss removal
Moss work since 2021
Five years of clearing moss off houses around Nanaimo, from roofs and paths down to the narrow parts of a window frame.
Insured and WCB-registered
Upper-floor windows mean ladder work against the wall of your home. We carry insurance and WCB registration for exactly that kind of work.
Locally owned
We are a local outfit, and whoever looks at your windows for the quote is part of the crew that comes back to clean them.
We make it right
If a frame we cleared is not done properly, tell us and we come back to sort it out. That is our guarantee.
Got questions?
Window moss questions
Is this the same as window washing?
No. Window washing is about the glass. We are working on the frame around it: the sill, the corners, the track the sash runs in and the drain slots at the bottom.
The glass often looks better once the frame is clean, because the green run-off stops streaking down it, but a clear view is not what the visit is for.
What exactly is a weep hole?
It is a small slot, usually with a little plastic flap or cover, along the bottom outside edge of the frame. Rain that gets past the outer seal collects in the bottom channel and is meant to drain out through those slots.
If yours have moss or grit in them, or water still sits in the channel the morning after a downpour, they are not doing their job.
Can I test my own weep holes?
On ground-floor windows, yes. Slide the window open, pour a cup of water slowly into the bottom track and look outside. Water should come out of the slots within a minute or so.
If it pools in the track or seeps out somewhere else, the slots are blocked. Upper-floor windows are where most people call us, because doing the same test from a ladder is not much fun.
Why not just spray the frames with a pressure washer?
Because the jet goes where you do not want water: past the frame seals, into the wall behind the trim and against the edge seal of a double-glazed unit. A frame that was only mossy can end up leaking.
We use hand tools and a small amount of water at low pressure instead. Higher pressure is kept for the jobs that need it, such as concrete, which has its own page for driveways and sidewalks.
My windows are vinyl. Can they still be damaged?
The vinyl itself will not rot, but the frame is hollow and the sealed glass unit sits in it. Water that cannot drain out of the bottom chamber gets at that edge seal over a few winters, and once it lets go you see a cloudy haze between the panes that no cleaning will shift.
The wood around the window, such as trim boards and the rough opening behind them, can still rot if water is getting into the wall.
Which windows tend to be worst?
North-facing ones, ground-floor windows behind shrubs, anything under a carport or a deep overhang, and windows facing a stand of fir or cedar. Those frames hardly dry between October and March.
On hillside houses, the lower windows on the uphill side often stay damp longest, because the bank beside them blocks the sun and the breeze.
Can this be done on the same visit as my roof?
Yes, and most people book it that way. The ladders are already up, and the shaded side of the house that grows moss on the roof is usually the side growing it on the windows too.
Mention it when you ask for a roof moss removal quote and we will price the windows as a separate line.
Will the moss come back in the frames?
Over time, yes. A shaded frame on this coast collects grit and spores every year. Keeping the weep holes open is what matters most, and a look once a year, ideally in early fall before the rain settles in, keeps them that way.
Window Moss Removal in Nanaimo and the mid-Island
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