Possible Cause #1: Condensation If the ground is cold but the air is warm and humid, water vapor from the air will condense on the cool concrete surface.
As a general rule, the simplest recipe for concrete calls for around 10 percent cement, 60 percent sand or aggregate and 15 percent water, with a little bit of Too Little Cement. Just as it’s critical to have the right amount of water, you do not want too much or too little of the other ingredients. A couple more items to examine are: spalling, or frozen.
While I was reading we ran into the question “Why does concrete get wet when it’s Cold?”.
When relatively warm, moist air comes in contact with a very cool concrete slab, the cold temperature of the concrete will cause the air that comes in contact with it to cool. If the air cools at or below the dew point, it will begin to condense on the surface of the concrete, thus causing the wet and sometimes misty looking concrete surface.
Why is my concrete floor so damp?
In order to resolve damp issues, you first need to figure out why your concrete floor is damp. There are a few common reasons why your garage floor feels wet. The most common is old fashioned condensation, otherwise known as sweating. The issue could also be caused by poorly installed concrete (moisture below the slab).
This of course begs the query “Why is my concrete floors damp?”
Concrete is a naturally very porous material and water can rise up or travel through capillaries which can lead to damp floors and mould issues. The easiest problems to isolate and repair with damp-floors are issues with above-ground services, such as leaking pipes.
When we were researching we ran into the question “Why are concrete floors so difficult to fix?”.
One answer was concrete floors especially can create problems that can be more difficult to solve. Concrete is a naturally very porous material and water can rise up or travel through capillaries which can lead to damp floors and mould issues. The easiest problems to isolate and repair with damp-floors are issues with above-ground services, such as leaking pipes.
Walls are not the only element of a building that is susceptible to damp problems. Floors can be equally as likely to suffer from moisture ingress and penetration. Concrete floors especially can create problems that can be more difficult to solve.
What causes rising damp in walls?
If the damp patches rise from ground level, or there is a powdery deposit on wall surfaces, the cause is rising damp. This damp occurs when there is a failure or absence of a damp-proof course. If you live in a flat above ground level, you won’t have to deal with rising damp.
Why does my concrete floor sweat?
Humidity —warm and humid air condenses into surface moisture when it comes into contact with the cool surface of your concrete floor or slab. Faulty/Missing Vapor Barrier —moisture from the ground can seep up and through the concrete. Bone Dry’s Etch-a-Crete is a great solution to open pores in a concrete slab.
Why Floors Sweat For most floors, condensation is the main reason for the sweating, especially in warm weather. When warm humid air from outside comes into contact with the cold concrete the air rapidly cools and condenses on the surface causing the wetness.
Make sure buildings have proper ventilation systems in place. This is very important since most humidity inside a building is created by the occupants. Vapor barriers should be in place between native soil and below-grade concrete. This is critical to preventing sweating slab syndrome. Insulation should be placed in the correct areas.
The concrete surface must be kept clean from any salts and deposits. Often, sweating slabs occurs because air inside the structure can’t easily flow out. A couple more things to pay attention too are: use hvls ceiling fans, de-humidification units, or use low-permeance and low-slab retarders.
Why does Grout loss happen in concrete?
This appears as steps at the surface accompanied by grout loss. Caused by leakage at construction or formwork joints. Ensuring that formwork joints are grout tight reduces the risk of its occurrence.