Does Insulating Your Home Actually Make Condensation Worse?
There is a famous Arabic proverb that says: Anything that exceeds its limits, turns into its
This proverb applies to many things in life: exercise, jealousy, eating fruits, drinking alcohols
All these are healthy habits and activities that help us enjoy a better life, but if done excessively,they can give the opposite outcomes and cause more harm than good.
Does this apply to domestic insulation too?
We all know that insulation helps to keep our indoors warm, dry, and comfortable. But can too
much of it lead to condensation and humidity issues?
That’s what this article is all about.
We will discuss the impact of insulation on humidity. How does it help to reduce
damp problems? And whether over-insulating can cause condensation problems?
Without further ado, let’s dive in.
TLDR; (Too Long, Didn’t Read!)
Yes, too much insulation can cause condensation. This is because over-insulating leads to poor ventilation inside a house and as a result, prevents the humid air from escaping outside and becomes more prone to condense on cool surfaces and walls.
How Does Condensation Appear?
Before we can answer whether too much insulation causes condensation, we need first to understand
how condensation happens. Fair enough? Let’s go.
Simply put, condensation occurs when warm and humid air hits a cooler surface or object.
The thing to note here is that warm air can hold more moisture than cool air. Therefore, when hot air hits a cold surface, it loses much of its ability to hold water and as a result, all the excess moisture gets exposed in the form of water droplets on the touched surface.
Have you ever wondered why tiny bubbles form on a glass of cold water in summer? This is because
hot summer air can hold large amounts of moisture, but when it comes into contact with a cool surface
(the glass of water), it loses its ability to contain moisture, which, at that moment, goes quickly
from a gaseous to a liquid state (The bubbles).
Unfortunately, this example of the water class is not the only form of condensation that we
encounter in our daily times.
In fact, there are many other forms of condensation that occur in our homes, some of which can lead
to uncomfortable living conditions.
Typically, condensation occurs in a home when damp and warm air from activities such as cooking,
bathing, drying clothes, breathing, and exercising hits interior walls, celling and windows.
As we said, when this happens, the air cannot hold as much vapor as before and all the excess
moisture turns into a liquid state and settles on the affected surface initiating mold growth and
This explains why places like the kitchen, bathroom, and laundry room are generally the most prone
to moisture issues and fungal growth.
How Does Insulation Help With Condensation?
Yes, you read it right. Insulation is meant to reduce condensation.
First, what you need to understand here is that condensation in more common during cold weather.
Why? Because when it in chilly outside, the difference in temperature between the air circulating
inside the house and the perimeter walls increases, causing the indoor air to lose more water vapor
(more condensation) when it touched those walls.
Now how does insulation help with that?
Well, when you put an insulation layer against a wall, the inner surface of the wall becomes less
affected by the weather.
The wall might be cold on the outside (the outer surface, but the insulation material prevents the low temperature from getting inside and the inner surface of the wall remains warm.
This keeps the difference in temperature between the interior air and the walls small, and as a
result, reduces the risk of condensation.
In other words, with good insulation, the walls in your home stay warm and therefore don’t cause the
air to lose too much water when its hits them.
Worth noting that this applies to your windows too.
A single-glared window in a poor insulator. As a result, when it’s cold outside, the inner surface
of the window becomes cold too, increasing the risk of condensation.
On the flip side, double-glazed (or triple-glazed) window stay warm on the inside and leave less
chance for air to condense.
What Happens When There Is Too Much Insulation?
With all that we have said about insulation and its ability to reduce moisture issues, insulation alone is not enough. If you want to avoid home condensation, you still need to
ensure adequate ventilation and air circulation in your home.
Yes, insulation will keep your interior warm and therefore been likely to condense air. But if that
air cannot escape to the outdoors, it will continue to circulate around your property until it finds a
cool surface to condense on.
In other words, insulation cannot heat all the surfaces in your home. Undoubtedly, there will still be cold pieces that provide favourable conditions for the air to condense.
So while you invest money and time to insulate your building, do not forget about ventilation and
make sure there is enough air exchange with the outdoors.
The goal is to let cool outdoor air blow into your home and redirect moist indoor air before it
condenser on a cool surface.
Now the question is, can you do that when there in too much insulation in your house?
If you are so concerned about insulating, chances are that you don’t care as much about
ensuring proper ventilation.
Also, insulation in designed to maintain the indoor heat and present it from escaping. But by doing
so, I can also trap the damp air and force iT to stay inside.
Think of i this way.
Will air circulate properly if you put earth wool in every wall and ceiling in your house and you
close all your doors and double-glazed windows?
Will there be any air exchange with the outside if you insulate (or close) any surface that separates your home and the exterior?
And with you leave any opening through which interior air can escape if you are too concerned about
Let’s face it. That’s pretty hard, isn’t it?
This is the fundamental problem with too much insulation.
As a rule of thumb, the more a house in insulated, the more it becomes airtight, and the less air
it exchanges with the outside.
This presents the damp air from getting out, and as a result, keeps circulating inside until it
What Is The Optimal Insulation Level That Prevents Condensation??
In general, there isn’t a particular limit on how much insulation you should have in your home.
As we said, you want to maintain some sort of balance between insulation and ventilation.
In other words, do not over-insulate so you don’t trap the damp air inside and force it to condense
somewhere. And at the same time, do not over-ventilate so you don‘t let the chilly air comes in.
The goal is therefore to find a sweet spot where you meet both ends:
1 — An insulated (and warm) house;
2 — Proper air exchange with the outside.
How to do that? Well. Here is a list of some best practices and recommendations:
- Do not insulate every square inch of your house. Focus more on the rooms that are most prone to
condensation. This includes the kitchen, bathroom, bedroom, laundry room, etc. For the other
places, the risk of condensation is generally lower and therefore a heating system is all you need
to feel warm and comfortable.
- Track the cold spots in your house. That’s where you should have insulation. You can do that by
tracking where mold stains grow and where condensation occurs.
- During this, do not overlook previously insulated walls. Insulation materials can easily break
and form a thermal bridge with the outside. So make sure to regularly inspect your insulation
quality and renew it if necessary.
- Make sure to install extractor fans and cooking hoods in your kitchen and bathroom. These
products help to redirect the damp air outside before it hits the roof and condenses.
- If possible, install trickle vents on your windows frames. These small openings allow subtle
ventilation through closed windows without causing chilly airflows.
- Similarly, try to have passive vents on your roofs or in the top of your ceilings. These are
wind-driven ventilators that allow the air to flow through the building.
- Loft and underfloor vents are also good. These areas are usually airtight, and therefore, a vent
will surely help them breathe and have more fresh air.
Summary on Insulation vs Condensation.
Too much insulation can cause condensation.
Lagged lofts, wood-insulated walls, and fancy double-glazed windows help to maintain indoor heat,
but they also trap moist air inside, and as a result, force it to condense somewhere.
In other words, over-insulating reduces air ventilation inside a building and therefore presents
the damp air from escaping outside.
To preVent that, householders should put effort into maintaining harmony between insulation and
This includes only insulating rooms that are most likely to have condensation problems. Also,
installing vents and extractor fans in airtight areas with help the building to breathe and get rid
of moist air before it condenses on a cool surface.
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