Low-pressure wall treatment across St Keyne

What St Keyne walls are usually finished in

• Modern render, whether sand and cement or a thin-coat system, has a slightly porous face that holds airborne spores.
• Bead edges and stop ends on a rendered elevation are the details worth protecting from driven water.
• Painted masonry can be cleaned, though a paint film that has already lost adhesion will lift where it was going to fail anyway.
• Masonry paint over render adds a film that traps moisture if the substrate was damp when it was applied.
• The mortar between granite blocks is usually lime, which sets the whole method for the wall.
• Iron staining from old fixings in granite is a separate problem from growth.

Low pressure, longer dwell

1. 1.Everything is packed down before the last inspection, so the wall is judged clear of kit.
2. 2.On thin-coat systems the lance is kept moving, because holding it still in one place is how a shadow mark gets left behind.
3. 3.Where a lean-to gutter runs at wall height, it is cleared first so it does not overflow mid-visit.
4. 4.Treatment goes on from the bottom of the elevation upwards, which stops clean streaks forming where liquid runs onto dry surface.
5. 5.Every hose junction is checked before pressure goes on, because a burst at a coupling floods a border.
6. 6.Anything applied is applied once and given time, rather than applied twice in a hurry to look busy.
7. 7.The van is parked so hoses do not cross a footpath, and matting goes down where they have to.
8. 8.Render beads and stop ends are inspected as work reaches them, because a lifted bead traps water behind the finish.
9. 9.Reach is taken from the ground with a telescopic lance wherever the elevation allows, which keeps ladders off soft render.
10. 10.The strength of mix is stepped up only after a weaker one has been given its full dwell and judged.

Small things that make the visit smoother

• Say if there is a wasp or bird nest under the eaves, and we will plan around it.
• Clear the base of the elevation of pots, ornaments and loose paving where you can.
• Say if you would prefer the front done on a different day from the back.
• Bring in washing, cushions and anything fabric that lives against the wall.
• Say whether the elevation backs onto a public footpath.
• Let us know whether the gutters have been cleared in the last couple of years.
• Point out any alarm sensor mounted externally on the elevation.
• Say where the outside tap is, and whether it runs at any pressure.

Within a short run of St Keyne

• Crafthole (PL11)
• Talland (PL13)
• Trewidland (PL14)
• Lanreath (PL13)
• Plaidy (PL13)
• Burraton (PL12)

Questions St Keyne owners ask

Is the water mains-fed?

From your outside tap where there is one. Where there is not, we bring it with us.

Does the treatment stain paving?

No, and paving below the elevation is rinsed at the end anyway.

What about air bricks and vents?

Covered for the duration, uncovered before we leave.

Do you work on bungalows differently?

Only in that everything is reachable from the ground, which makes the visit shorter.

Will it strip my paint?

Sound paint is unaffected. Paint that has already lost adhesion may lift, which is why a test patch goes on first.

Can the whole house be done in one go?

Often, depending on size and access. Larger properties split naturally into two visits.

Can lichen be removed completely?

The organism is killed, and what is left weathers off. Deeply rooted lichen on stone can take a season to fade.

When does a treated wall show its final appearance?

Some change can be visible after treatment, while remaining dead growth may continue to weather away over the following days.

To sum up for PL14

Ask what will be used and how long it will be left on. The answers tell you everything. Getting the order of work right protects the money already spent on the parts that were cleaned first. Method, dwell, rinse, check. There is nothing else to it.