Painters and decorators in Penryn, from the trading estates to the granite town

Penryn does more trading than its size suggests. Kernick and the estates around it, the yards and units along Commercial Road, the businesses on the wharves by the river: joinery shops, motor trades, builders' merchants, marine and boat businesses, small manufacturers, storage, and the offices that go with each of them. Decorating a unit is a different job from decorating a house, and it is planned around trading rather than around the paint.

The workshop itself is usually blockwork walls, a steel frame, roller shutters and a concrete floor. What the owner wants is a wipeable, bright finish on the walls, the steelwork and doors rubbed back and given a proper primer where rust has started, and the floor sealed if it is to be cleaned rather than swept. That is industrial coatings work, done to the product's data sheet rather than to a colour card, and phased so one bay or one end of the shed is out of use at a time while the rest keeps going. Deliveries, forklifts and the site's own rules set the order of work, not us.

Almost every unit has an office, a reception or a mess room built into a corner of it, and those are ordinary commercial decorating: plasterboard walls, suspended ceilings, doors and frames, done early, late or on a Saturday so the desks are back in use on Monday. The shopfronts on the old street through the town centre are the same problem in a smaller space. A shop cannot close for a week, so the front is done outside opening hours, the timber fascia and window frames rubbed back and rebuilt in full coats, and the sign left masked and clean.

Above the town, the Penryn campus at Tremough is shared by the University of Exeter and Falmouth University, and around it and along the roads down into the town there is a lot of newer housing: student blocks, estates built since the 1990s, and older terraced houses let to students by the room. Inside a new-build house the work is straightforward, and the most common job is the first proper redecoration after the builder's single coat of pale emulsion has given up.

The student houses run on the same calendar as Falmouth's, emptying in early summer and filling again in September, and everything about how we approach them, the wipeable specification, the anti-mould work in cold bedrooms, taking several houses as one run of weeks through an agent, is set out on the Falmouth page rather than repeated here. The one Penryn difference is parking. The streets nearest the campus and the centre are tight, and where a house has no drive we sort out where the van and the materials go before the first morning, not on it.

Penryn's centre is older than Falmouth's by centuries. Broad Street, with the town hall and its clock tower at the top, the merchants' houses and the streets running down towards the river are largely granite, and a great deal of it is listed and all of it sits inside the conservation area. Behind the street fronts are courtyards and narrow passages, houses reached on foot through an arch or down steps, and rear elevations no vehicle can get near. Access is the first thing we look at on an exterior here, because a job that is easy at the front can mean carrying every tower section and every tin through a passage by hand, and the quote sets out how each elevation is to be reached.

These are solid walls, granite or rubble stone with lime pointing and often lime render and lime plaster, and the rule is that they have to breathe. A masonry paint that seals the wall traps the water the wall has always been letting out, and the damage shows as blown render and damp plaster inside within a few winters. So old walls get a breathable finish, distempered or limewashed surfaces are taken back to something sound before anything modern goes on, and where a wall wants a true lime finish rather than paint we say so and work with whoever does it. Inside, lime plaster is filled with something that moves with it, never a hard filler that cracks out by spring.

Then there are the sash windows, panelled front doors and fanlights, most of them old and painted many times. They are rubbed back to sound paint, the putty renewed where it has failed, soft timber treated and bare wood primed, the coats rebuilt so the joints are sealed and the sash still slides. On a listed house the colour is part of the conversation: heritage shades suit the granite, strong modern colours rarely do, and where consent is needed for a change we say so before a sample goes on. Penryn is sheltered, up a creek rather than on the open sea, so the weather is kinder here than it is on the Falmouth seafront, and the enemy of these houses is not salt but damp. Get the wall breathing, the timber sealed and the gutters running, and a repaint on Broad Street will hold for years.