How to maintain clay tiles and bricks in Ghana's tropical climate

Clay brick and terracotta tile carry a reputation that is, in one sense, almost too good: they are so inherently durable that owners sometimes assume they require no attention whatsoever. In temperate climates that assumption is largely justified. In Ghana, it needs a small but important qualification.

Ghana sits within the tropical wet-and-dry zone. Annual relative humidity ranges from around 77 percent on the coast to 65 percent in the north — with coastal Accra routinely exceeding 85 percent during the main rainy season. Rainfall averages between 780 mm and 2,160 mm per year depending on region, delivered in intense, roof-hammering downpours. Between November and March, the harmattan arrives from the Sahara carrying fine silica dust that abrades and deposits on every exposed surface. UV radiation is intense year-round.

This is not a hostile environment for clay — far from it. But it is an active one. Understanding what Ghana's climate does to clay materials is the starting point for keeping them looking exceptional, decade after decade.

Why clay still wins in the tropics

Fired clay is a kiln-transformed material. At temperatures exceeding 1,000°C, the raw clay minerals vitrify — they fuse into a dense, glassy matrix that is chemically inert, dimensionally stable and highly resistant to moisture absorption. This is fundamentally different from unfired or cement-based materials, which remain porous and chemically reactive throughout their lives.

Research from Leeds Metropolitan University, studying 860 brick structures, found that well-maintained clay brick constructions can last 500 years or more under ordinary conditions. The Brick Industry Association's Technical Note 46, the definitive industry maintenance reference, confirms that brick walls themselves have an estimated repair timeline of over 100 years — far exceeding every other common building material. What deteriorates first is not the brick: it is the mortar between bricks, the sealants around windows, and the biological growth that the tropics encourage on any damp surface.

This distinction matters. When you maintain clay in Ghana, you are not fighting the material — you are managing its environment.

Ghana's four maintenance challenges

1. Biological growth: algae, moss and lichen

This is the most visible and most Ghana-specific challenge. The combination of high humidity, warmth and seasonal rainfall creates near-ideal conditions for microbiological colonisation of masonry surfaces. Algae appear first — typically as a green or black staining on north-facing walls and shaded areas where moisture lingers longest. Moss and lichen follow on surfaces that stay wet for extended periods.

Beyond aesthetics, biological growth matters structurally. Algae and moss trap moisture against the masonry surface, slowing the natural drying cycle. Lichen root filaments penetrate mortar joints and, over years, create micro-fractures that accelerate moisture ingress. On terracotta floor tiles, algae make surfaces dangerously slippery during the rainy season.

The correct approach is a two-step one. First, treat the growth rather than simply scrubbing it away. A solution of diluted sodium hypochlorite (household bleach at 1:10 dilution with water) or a proprietary biocidal masonry cleaner, applied with a soft brush and left to dwell for 15–20 minutes, kills the organism at the root. Then rinse thoroughly with clean water. Do not use a high-pressure washer at close range on clay tiles — sustained high pressure at distances under 300 mm can erode the tile surface and force water into hairline cracks. A maximum of 1,200 PSI at appropriate standoff distance is the safe limit for clay surfaces.

Prevention, as always, is easier than cure. Trim back trees and large shrubs that create permanent shade on walls. Ensure gutters and downpipes are clear so that water does not back up and run across wall faces. Adequate roof overhangs — which Ghanaian vernacular architecture understood instinctively — go a long way towards keeping walls dry.

2. Efflorescence: the white salt tide

White, powdery or crystalline deposits appearing on brick or tile surfaces are a familiar sight in Ghana, particularly in the first two rainy seasons after a building is completed. This is efflorescence — soluble salts migrating from within the masonry or the ground, carried by water to the surface where evaporation leaves them behind.

In Ghana, high seasonal humidity slows evaporation from the masonry surface, extending the window during which dissolved salts can travel. The harmattan season, when humidity drops sharply, accelerates surface evaporation and can trigger visible deposits even on buildings that appeared clean through the rains.

The good news: efflorescence is almost always cosmetic rather than structural, and first-year efflorescence commonly disappears naturally through normal weathering and rain. Where it persists, the Brick Industry Association recommends scrubbing with a stiff brush and clean water first — avoiding acid-based cleaners unless the efflorescence is severe and the brick has been pre-wetted and will be thoroughly rinsed, as improper acid cleaning etches mortar joints and increases long-term moisture penetration.

Prevention begins at the design stage: use clean washed sand and potable mixing water in mortar, ensure adequate flashing and weep holes are installed above all lintels and at wall bases, and seal the tops of freestanding walls with a proper coping that sheds water away from the face.

3. Mortar joint deterioration

The mortar joint is the weakest element in any clay brick assembly. The Brick Industry Association's maintenance data shows mortar walls have an estimated repair timeline of 25 or more years under normal conditions — but in Ghana's aggressive wet-dry cycling, this period can be shorter on exposed parapets, copings, and retaining walls that face more intense weathering.

Signs that mortar joints need attention include: visible cracking along the joint line, mortar that sounds hollow when tapped, mortar that crumbles when a key is drawn across it, and — importantly — damp patches appearing on interior walls directly below suspect joints. Left unaddressed, deteriorating joints allow water to penetrate the wall cavity, leading to staining, mould growth on interior plasterwork and, eventually, corrosion of any embedded metal ties.

The repair process — repointing or tuck-pointing — involves raking out the damaged mortar to a uniform depth of at least twice the joint width (or until sound mortar is reached), cleaning the joint of all debris, and packing in fresh mortar in thin layers. The BIA recommends Type N or O mortar for repointing work, as these lower-strength formulations are more compatible with the existing brick and less prone to causing spalling. Critically, the new mortar should be slightly weaker than the brick itself: if differential movement occurs, it should crack the mortar — which is replaceable — not the brick, which is not.

4. Harmattan dust accumulation

The harmattan — the dry, north-easterly trade wind that sweeps across West Africa between November and March — carries fine silica and clay dust from the Sahara. In Ghana it arrives with particular force in the north but is felt across the entire country. On textured terracotta tile and rough-faced clay brick, this dust lodges in surface pores and accumulates in grout joints, eventually discolouring the material and, where it combines with organic material, providing a substrate for biological growth in the subsequent rainy season.

Post-harmattan cleaning — ideally in March or April before the first rains — is the single most cost-effective maintenance intervention for terracotta tile in Ghana. For exterior wall surfaces, a thorough brushing followed by a rinse with clean water is generally sufficient. For interior terracotta floor tiles, a pH-neutral stone cleaner (avoid acid-based cleaners, vinegar or ammonia-based products, which can strip sealant and discolour grout) applied with a damp — not wet — mop, followed by thorough rinsing, restores the tile to its natural warmth.

Sealing: the great debate

Should clay tiles and bricks in Ghana be sealed? The answer depends on what is being sealed and why.

For interior terracotta floor tiles, sealing is strongly recommended. Unglazed terracotta is porous and will absorb cooking oils, foot traffic dirt and water if left unsealed. The ideal product is a penetrating silane-siloxane sealer — not a surface-forming coating. These penetrate below the tile surface, chemically bond with the silica in the clay, and create a water-repellent matrix while preserving the tile's ability to breathe. Film-forming sealers (polyurethane varnish, high-gloss coatings) should be avoided on clay: they trap moisture beneath the surface, are prone to peeling in humid conditions, and fundamentally alter the character of the material. A penetrating sealer applied every three to five years maintains effective protection without changing the tile's appearance.

For exterior clay brick walls, the Brick Industry Association is explicit:

Properly designed and constructed brickwork — with adequate flashing, weeps and drainage — does not need to be sealed. Sealing exterior brickwork should only be considered where specific water penetration problems exist and where the source of penetration has already been identified and rectified. Applying sealer to brickwork with existing water ingress issues traps moisture inside the wall, worsening rather than resolving the problem.

Your Ghana maintenance schedule at a glance

Task	Frequency	Season
Visual inspection of walls, joints, copings and flashings	Twice yearly	Both seasons
Post-harmattan dust removal (brush + water rinse)	Annually	Dry season end
Biological growth treatment (algae / moss)	As required — typically annually in humid zones	Dry season
Gutter and downpipe clearance	Before each rainy season	Pre-rains
Interior terracotta tile cleaning (pH-neutral cleaner)	Monthly (routine); deep clean every 6 months	Both seasons
Efflorescence check and treatment if present	Annually (post-harmattan)	Dry season end
Mortar joint inspection and repointing where needed	Every 10–15 years (or as required)	Dry season
Interior terracotta tile re-sealing (penetrating sealer)	Every 3–5 years	Dry season
Sealant joint inspection (around windows, doors, expansion joints)	Every 5 years	Both seasons

What to avoid

Several common practices cause more harm than good and deserve explicit mention:

• Acid washing without pre-wetting and thorough rinsing. Muriatic acid (hydrochloric acid) is effective for removing stubborn efflorescence and mortar smears — but applied incorrectly to dry masonry, or without thorough pre-wetting and post-rinsing, it etches mortar joints and increases the surface's long-term susceptibility to staining and moisture penetration.
• Painting over brick. Paint forms a film over the brick face. In humid Ghana, moisture trapped between the paint film and the brick face causes the paint to blister and peel within two to three seasons — an outcome worse than an unpainted wall. Paint also prevents the natural breathing of the masonry wall and is extraordinarily difficult to remove once applied.
• High-pressure washing at close range. Sustained high-pressure water jets at distances under 300 mm can erode the surface of clay tiles, damage mortar joints, and drive water deeper into the masonry than natural rain ever would.
• Allowing ivy and climbing plants to grow on brick walls. Ivy root suckers penetrate mortar joints, conduct moisture directly into the wall, and when removed pull facing material with them. The BIA Technical Note 46 is emphatic: vines must be cut — never pulled — from brickwork, and the dried shoots left to desiccate for two to three weeks before being brushed away.
• Using bleach on unglazed floor tiles. Bleach is appropriate for treating biological growth on exterior masonry. On interior unglazed terracotta floor tiles, it strips the protective sealer and can permanently discolour natural clay — use a pH-neutral cleaner instead.

A note on Ghana's rising damp problem

A particular maintenance concern in Ghana — flagged explicitly in local construction research — is rising damp: moisture migrating upward from the ground through masonry by capillary action. This appears as a distinctive tide mark on lower sections of walls and is exacerbated by the lack of effective damp-proof courses (DPCs) in many existing structures. On clay brick walls with rising damp, efflorescence and biological growth at low levels are symptoms, not the cause. Treating the symptoms without addressing the missing or failed DPC is wasted effort. Where rising damp is confirmed, remedial intervention — either chemical injection of a damp-proof barrier or mechanical insertion of a physical DPC — is needed before any surface maintenance will hold.

When to call a professional

Most routine maintenance described above is within the capability of a diligent homeowner or a competent general handyman. However, call a specialist mason in the following situations: structural cracks that run through brick units (not just mortar joints), cracks that follow a stair-step diagonal pattern across multiple courses, any sign of wall movement or out-of-plumb conditions, and extensive repointing covering more than a few square metres. These conditions may indicate structural movement or foundation issues that require engineering assessment before cosmetic repairs are attempted.

We're here when you need us

Bricmates supplies premium burnt clay bricks and terracotta tiles across Ghana from our depots in Accra (Kwabenya) and Kumasi (Fumesua). We advise on specification, installation, and — as this guide illustrates — long-term care. If you have a specific maintenance question about clay materials on your project, our team is available on WhatsApp seven days a week.