Roof restoration for moss, lichen and failed ridge pointing

The job most mountains roofs actually need

Across the Blue Mountains, restoration outnumbers replacement by a wide margin, and that is not a sales position — it is what the housing stock and the climate produce. The tiles on a 1960s or 1970s roof at Springwood or Blaxland are frequently still structurally sound. What has failed is everything around them: the bedding mortar under the ridge caps, the pointing over it, the valley irons, and the factory surface coating that has long since chalked away.

That is a restoration, and it is a fraction of the cost of a re-roof.

Call (02) 4703 5000 for a free inspection and a written quote. If the roof is genuinely past restoring, we will tell you that too.

What happens on a shaded pitch

Stand in a street in Leura, Hazelbrook or Lawson and look at the roofs. On most houses one pitch is noticeably darker and greener than the other. That is the southern plane: least direct sun across the year, slowest to dry after rain and frost, and often sitting under established canopy.

Moss and lichen establish there because the surface stays damp long enough for them to take hold. The damage follows:

• The growth holds water against the tile instead of letting it run off.
• Shallow roots work in between tiles and under the overlaps, lifting edges and opening entry paths.
• Litter and organic matter build up with the growth and dam the water flow.
• The constantly wet surface accelerates the breakdown of the tile coating underneath it.

On the northern plane of the same house, the tiles can still be reasonably clean. The shaded side is where the roof ages, and it is where a restoration earns most of its value.

Freeze-thaw, and the mortar at the top of the roof

Above Lawson, and emphatically at Katoomba, Medlow Bath, Blackheath and Mount Victoria, the roof goes through repeated freezing and thawing through winter. Frost is common on winter mornings at this altitude, and settled snow falls two or three times in a typical season.

Here is what that does to a bedded ridge. Water soaks into the mortar. Overnight it freezes and expands. In the morning it thaws. Repeat that across enough winters and the mortar fails from the inside: first hairline cracking, then pieces lifting out, then caps that rock underfoot. By the time you find mortar crumbs in your gutter, rain is already getting in at the highest line on the roof and travelling the length of the framing before it shows on a ceiling.

This is why upper mountains roofs need repointing sooner than roofs on the coastal plain, and why the right material is a flexible pointing compound that can tolerate movement rather than a rigid sand-and-cement mix that cannot.

What a restoration includes

1. Inspection first. Walk the roof, check every ridge and hip, valleys, flashings, tile condition and gutter line. Photographs with the quote.
2. Replace broken and slipped tiles. Matched where possible, including the older discontinued profiles from secondhand yards.
3. Clean down. Pressure washed at a pressure matched to the tile, clearing moss, lichen and organic build-up. Downpipes protected and debris collected, not flushed into your stormwater.
4. Biocide treatment where growth is established, so the surface is dealt with rather than simply knocked back.
5. Rebed the ridge caps. Lift the caps, remove the failed mortar, rebed them properly.
6. Repoint with flexible pointing compound in a colour matched to the roof.
7. Clear and check valleys, replacing corroded valley irons and any rotted valley boards found underneath.
8. Seal and recoat. A primer or sealer coat to bind the cleaned surface, then membrane coats to the manufacturer specification.
9. Clean up. Gutters flushed, site cleared, written workmanship warranty issued.

What a restoration will not fix

Worth being blunt about the limits:

• It will not save a roof whose battens are failing. If the timber under the tiles has been repeatedly wetted and gone soft, coating the top does nothing. That is a roof replacement.
• It will not fix a structural sag. Wavy courses usually mean a framing or batten problem.
• It will not rescue crazed, porous terracotta that has lost its integrity through the body of the tile.
• It is not a leak diagnosis. An active leak with an unknown source wants a roof repair or a written inspection report first.

If the roof is in one of those categories, you will hear it from us at the inspection, not after you have paid for a coating.

Working around mountains weather

Restoration is weather-dependent work. Coatings and pointing both need to cure, and three local conditions interfere with that:

• Frost. An uncured surface that freezes overnight is compromised. Above 900 metres that rules out a lot of winter.
• Fog. A roof sitting in cloud for three days is a roof that cannot be coated.
• Rainfall. The long-term Bureau of Meteorology average at Katoomba is around 1,400 mm a year, well above the coastal plain, and it falls across all four seasons.

The practical upshot is that we will book your job into a window that gives it a chance, and we will move it rather than coat a damp roof. If that is frustrating, it is still cheaper than doing it twice.

What moves the price

Roof area and pitch. Tile type, because terracotta and concrete need different treatment. How many tiles need replacing. How much of the ridge and hip line needs rebedding rather than just repointing. Access, which on a steep treed block can be the largest single factor. And whether valleys or flashings need renewal once the debris is cleared.

No figures before the inspection. The quote is written, itemised and free.

Book a look at your roof

Call (02) 4703 5000 or send the quote form with your suburb, the roof type and roughly when it was last done. We cover the whole ridge — see where we work for the suburb list. Work is carried out by established, licensed and insured roofing contractors working to NSW Fair Trading requirements.