PL14 moorland granite: lichen, high rainfall and hard stone
PL14 climbs from Liskeard up onto the southern edge of Bodmin Moor. Granite, lime render and Cornish slate, rainfall well above the coastal average, and the heaviest lichen growth of any district we cover.
PL14 covers 22 places we work in, 11.4 to 21.7 miles from our base at 58 Reddington Road, Plymouth (Cornwall, Cornwall Council) - all inside our 20-mile radius of Plymouth.
Lichen is a slower, harder problem than algae
Algae is a film that washes off. Lichen is an organism with a root structure that grips into the surface of slate and mortar, and it does not come off with water at any sensible pressure.
It needs a biocide and it needs time. On a badly colonised roof up at Minions or St Cleer the visible improvement continues for months, not days, and anyone promising an instant transformation is planning to use a lance on your slate.
Cornish slate roofs at altitude
Slate up here is often original, sometimes hung on the walls as well as laid on the roof, and always brittle in frost. We treat it from ladder or pole and stay off the covering.
Timing the work around the weather
There is no point applying treatment into driving rain. On the moor we plan around forecast dry windows, which occasionally means moving a booking - we would rather do that than take your money for a job the weather will wash off.
Reached via A38, A390, B3254, local lanes off A38. Recorded wall finishes: granite, painted render, lime render. Roof coverings: slate, Cornish slate.
Towns and suburbs in PL14
Villages and neighbourhoods in PL14
- Minions - wall softwash
- Henwood - wall softwash
- Darite - wall softwash
- Common Moor - wall softwash
- St Ive - wall softwash
- Pensilva - wall softwash
- Merrymeet - wall softwash
- Trewidland - wall softwash
- Herodsfoot - wall softwash
- St Keyne - wall softwash
- Doublebois - wall softwash
- Twowatersfoot - wall softwash
- Sharptor - wall softwash
- Quethiock Village - wall softwash
Questions we get asked in PL14
- Why does lichen take so long to disappear?
- Because it dies before it detaches. Weather removes the dead growth gradually over the following weeks and months.
- Would pressure washing be quicker on a slate roof?
- Quicker and much more damaging. It strips the surface of the slate and forces water under the laps.
- Do you move bookings for rain?
- For treatment work, yes. Applying biocide before heavy rain simply wastes it.