When's the right time to repaint exterior woodwork in the Cotswolds?

The pub-lounge advice on exterior paint is usually contradictory. "Do it in the spring." "Do it when it's warm." "Don't do it in direct sun." "Do it before the weather turns." All right, in a sense, all useless without context.

Here's what actually matters in a Cotswold climate.

The three conditions that have to be right

1. Temperature

Most modern exterior paints want a surface temperature between 8 and 25 degrees while they dry. Below 8 and the paint doesn't level or cure properly. Above 25 and the solvent flashes off before the paint flows, you get brush marks and a weak film.

In the Cotswolds that gives you May, June, late August and September as the reliable window. Mid-July is often too hot on south-facing walls. A freak cold week in June, and you sit it out.

2. Moisture in the wood

Moisture is the silent killer. If the wood's damp underneath, paint on top doesn't stick, it floats, it peels in a year. I've seen immaculate-looking paint jobs blister off in sheets the following spring because no one waited for the wood to dry.

Rule of thumb: 48 hours of dry weather before painting. A cheap moisture meter (under £20) tells you the number. Below 16 percent, crack on. 18 to 20 percent, wait. Above 20 percent, definitely wait.

3. Dew and forecast

Paint drying overnight wants no dew. If you paint late in the afternoon and the forecast shows dew point close to overnight low, the paint film gets wet before it's cured. Mist marks, poor adhesion. So late-May early starts and finishing by 3pm is ideal.

Prep is 70 percent of the job

Most failures aren't from bad paint. They're from bad prep.

• Scrape any flaking paint back to sound edge. A good scraper and a wire brush do most of it.
• Sand everything else to give a mechanical key.
• Fill any cracks or nail holes with an exterior filler. Let it dry properly. Sand flush.
• Treat any bare wood with a primer meant for exterior timber. Don't skip this. Bare wood drinks the topcoat and leaves you a patchy finish.
• Mask window glass with tape for a clean sash line.

Paint choice in plain English

For windows, doors, fascia, eaves, and any timber that sees rain and sun, I use a modern exterior acrylic eggshell or satin. Breathable. Flexible. Handles the Cotswolds' temperature swings without cracking. Sadolin, Dulux Weathershield, Zinsser all make decent ones. Avoid anything too glossy, it shows brush marks more in a year.

Two topcoats over a primer is the standard. One coat is a false economy. You'll be back in three years instead of eight.

How long does it actually last?

On a well-prepped south-facing front elevation in the Cotswolds, decent paint lasts 6 to 8 years before you start seeing real degradation. North-facing is easier, call it 8 to 10. Windows sills get the worst of it and sometimes want a refresh in year 4 or 5.

A rough guide to cost

• Single timber sash window, prep and repaint: 2 to 3 hours work. Around £100 to £150 plus paint.
• Front door and frame: half a day. £150 to £200 plus paint.
• Standard four-bed detached, full exterior woodwork including fascias, eaves, windows, door: 4 to 6 days. Budget £1,200 to £1,800 plus paint.

I usually provide the paint at trade price, so the number includes that.

Don't let anyone talk you into painting in January

There's a certain school of tradesman who will paint all year round because work's work. I don't. If the conditions aren't right, I'll book you into the next decent week. The paint will look right in three years instead of one. You get a better job. I get fewer warranty visits. Everyone wins.