Painting Old Concrete Roof Tiles: The Right Way to Modernize a Dated 90s Green

The Scenario

A homeowner recently asked:

"What colour should I paint my roof"

The GardenOwl Diagnosis

The Assessment

You have a classic weatherboard bungalow that has good bones. The cladding is fresh, the timber deck is inviting, and the red brick base adds a nice bit of historic weight to the property. But there is a giant, dark green elephant in the room: the roof. Addressing this specific element is often key to avoiding The Chromatic Undertone Clash and significantly boosting curb appeal.

It’s a 70-year-old concrete tile roof that was painted a trendy forest green sometime in the late 90s. Now, it looks tired, dated, and patchy. You want to go dark—maybe charcoal—to modernize the look, but you are worried about making a mistake that you can’t undo.

The Trap: To Paint or Not to Paint?

Here is where most people get into trouble. My standard advice for concrete tiles is simple: Don't paint them.

If you take a raw concrete tile and slap paint on it, you are signing a contract for a lifetime of peeling, flaking, and scraping. Usually, a good soft wash is enough to clean off the oxidation and reveal a beautiful, natural grey stone look.

However, this case is different.

Because this roof was painted 25 years ago, the "raw concrete" ship has already sailed. Old concrete tiles are porous. Once they have been painted, that paint becomes the primary weather seal. If you let it deteriorate, those 70-year-old tiles will turn into heavy sponges every time it rains, soaking up water weight that your roof trusses weren't designed to hold forever. In this specific scenario, you have to paint it to maintain the integrity of the home.

The Solution: The Right Grey for Red Brick

Since we have established that you need to paint, the challenge becomes choosing a color that doesn't ruin the house's curb appeal or its internal temperature.

1. The "Void" Effect vs. Warm Charcoal

Your gut instinct might be to go "Black." Be careful. A pitch-black roof can look like a visual void—a black hole that sits on top of your house. It absorbs light and creates a harsh contrast that can make the house look top-heavy.

Instead, look for a Deep Charcoal or Slate Grey. But here is the secret sauce: look at the undertones.

Your house has a Red Brick base and a Warm Timber deck. If you pick a charcoal with a blue undertone (cool), it will clash with the brick and make the masonry look jarring. You need a charcoal with a warm or earthy undertone. This will visually "grip" the red brick and the wood, making the whole color palette feel intentional rather than accidental.

For more on handling tricky brick colors, read about why That ‘Ugly’ 70s Brown Brick Isn’t the Problem (Your Trim Is).

2. The Heat Factor

A black roof in the summer is essentially a radiator on top of your bedroom. Since you are repainting anyway, do not buy standard exterior masonry paint. You need a product specifically formulated for roofs with heat-reflective technology (often called "Cool Roof" coatings). These reflect infrared light even in dark colors, preventing your attic from turning into an oven. This is crucial for energy efficiency and for the longevity of the timber structure underneath.

3. Prep is Everything

Before you open a can, that roof needs to be spotless. If you paint over moss or grime, the paint will flake off in sheets within a year. You need to kill the organic growth first. See our guide on Slippery Green Slime: How to Kill Moss on Brick Pavers—the chemical principles for killing moss on concrete tiles are very similar.

Visualizing the Result

Roof paint is expensive, and labor is even worse. You do not want to realize you picked the wrong shade of grey when the scaffolding is already up.

I treat roof color selection like a "Safety Net." Before you commit, you need to see how that specific charcoal interacts with your specific red brick. I use GardenDream to test these combinations digitally. It allows you to toggle between a "Blue Black" and a "Warm Charcoal" to see which one harmonizes with your existing cladding and deck.

If you want to test this on your own yard, upload a photo to our Exterior Design App and see what this design would look like in your space.