Mould – The Silent Enemy in Our Homes

Tiny Insights for building naturally, building beautifully.

September 29, 2025

No.107 — Read old posts on Tinyfarmlab.com
Reading Time 5 minutes

Dr. Pradip Jamnadas often talks about mould in his patients.

He sees it show up as fatigue.
As allergies.
As brain fog.
As weakened immunity.

It’s invisible at first.
But silently, it grows.
In corners.
Behind furniture.
Inside our walls.


The World Health Organization has a term for this:
Sick Building Syndrome.

A syndrome where the very building you live or work in
makes you unwell.

Sick Building Syndrome

According to WHO estimates,
up to 30% of new or renovated buildings worldwide
may suffer from poor indoor air quality.

Symptoms?
Headaches.
Eye irritation.
Asthma.
Respiratory illnesses.
Low productivity.

Causes?

  • Poor ventilation.

  • Off-gassing from plastics, paints, adhesives.

  • Dampness and mould.

Our “modern” buildings have turned into boxes
that trap toxins inside.

You keep inoculating mould.
Again, and again.

We’ve faced it ourselves.
In our cement house in Delhi.
And again in Dehradun.

Every monsoon,
the black patches return.

Somehow,
we have accepted it as a seasonal thing.

Why does this happen?

Mould thrives when three things come together:
moisture, warmth, and still air.

In cement houses, moisture enters easily,
through hairline cracks,
leaky roofs,
faulty drainage.

Foundations without a proper
Damp Proof Course (DPC)
allow water to wick upward.
This is called rising damp.

Once inside,
cement and concrete
hold the water in.

We add plastic paints and chemical coatings on top,
making the walls even more suffocated.

These materials are dense,
non-porous,
and sealed with plastics.

The walls cannot “exhale.”

Moisture has nowhere to escape.
It stays trapped.
And mould spreads silently.

In the name of convenience,
we’ve built airtight,
toxic,
sick houses.

Credits: Unsplash

What Breathability Really Means

A breathable wall is not a “leaky” wall.
It’s a wall that can regulate moisture.

Think of a clay pot.
It keeps water cool,
not because it leaks,
but because it absorbs and releases vapour at the right pace.

Cement and industrial paints = vapour-tight.
They block movement of moisture.

Mud and lime = vapour-open.
They allow water vapour to pass through
while keeping the structure dry and balanced.

This self-regulation is why mud and lime walls
rarely suffer from mould,
from moisture in the air.

Lime – Nature’s Antimicrobial Shield

For centuries,
limewash was used not just for beauty,
but for health.

Lime has high alkalinity,
which kills bacteria, fungi, and mould spores.

Hospitals, schools, temples,
all were limewashed regularly,
because people understood
it kept spaces fresh and clean.

Today, we’ve replaced lime with
acrylic and vinyl paints,
toxic, suffocating,
and short-lived.

How Vernacular Architecture Prevented Dampness

Our ancestors understood water.
They built:

  • Raised plinths to keep floors above ground moisture.

  • Breathable walls of mud, stone, or brick with lime plaster.

  • Overhanging roofs and verandahs to protect walls from rain.

  • Courtyards and cross-ventilation to keep air moving.

Every design decision was thought out.

What Can We Do Now?
If the situation allows,

  • Repair damp walls with lime, not cement.

  • Use limewash or natural plasters instead of plastic paints.

  • Improve ventilation, let your walls and your body breathe.

  • Avoid sealing every surface in the name of “finishing.”

Sometimes,
looking back is the only way forward.

We pay for modern convenience
with hidden costs.

Mould is one of them.
Sick Building Syndrome is another.

Maybe it’s time to ask:

Is our house keeping us healthy,
or making us sick?

Love,
Raghav and Ansh

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What you can watch - Have you experienced Sick Building Syndrome?

Lime vs. Cement in Historic Buildings: A Clash of Materials in Conservation

When it comes to preserving and restoring historic buildings, the choice of materials used can be the difference between success and failure. Two materials that often come up in discussions about building restoration are lime and cement. Though they might seem similar at first glance, they are fundamentally different in terms of composition, behaviour, and how they interact with the structures they are meant to protect. In this blog, we’ll explore why lime is preferred over cement in historic bu

www.southeastsurveyors.co.uk/post/lime-vs-cement-in-historic-buildings-a-clash-of-materials-in-conservation?utm_source=chatgpt.com



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