Without a vapor barrier, moisture would continually wet the bottom of the slab, as vapor will continuously drive from the high humidity below slab to the relatively low humidity above the slab.
Does a concrete slab need plastic underneath? To stop any moisture damage occurring to a concrete slab, you should always put plastic underneath the slab. Due to the permeable nature of concrete, moisture can easily enter a concrete slab from the soil underneath it.
You are not required to have a vapor or moisture retarding barrier for outside concrete pads or unheated buildings. Although a vapor or moisture retarder or barrier is not necessary beneath concrete floors used for unheated carports, driveways, and outbuildings, some DIY enthusiasts and builders recommend it.
Oftentimes, moisture can seep through the dirt floor of your crawl space when you do not have a vapor barrier installed. Additionally, poor grading and improper vapor barrier installation can lead to rainwater leaking into your crawlspace, causing a huge standing water issue.
Long story short, yes you can pour concrete over dirt.
Because concrete is a very porous material, it will absorb any moisture that it contacts. This can cause pooling. Without crushed stone, pooling water will settle under it and erode your slab. Adding a layer of crushed stone will add proper drainage, as well as create a barrier between your slab and the ground.
Technically you can, but you really shouldn't pour concrete over grass. To maintain its tensile strength, concrete needs to be laid on a firm, even, and dry foundation. Grass and soil will naturally channel moisture into the concrete from below, which will likely result in it cracking over time.
Without a vapor barrier, moisture would continually wet the bottom of the slab, as vapor will continuously drive from the high humidity below slab to the relatively low humidity above the slab.
A vapour barrier is an important component in building construction. Its purpose is to help prevent water vapour from reaching building walls, ceilings, attics, crawlspaces or roofs, where it can condense and cause building materials to rot or grow mould.
The application of vapor barrier in exterior concrete is unnecessary due to the fact that water penetration does not matter. Any slab on grade that is enclosed and on the interior of a building should have a vapor barrier installed prior to pouring concrete, especially if flooring will be applied.
This means that in addition to groundwater working its way up, you also have a moisture-laden flooring surface slowly releasing water vapor for years. Concrete needs to breathe; it's the nature of the beast.
Plastic concrete curing covers seal off concrete and prevents water from evaporating. Concrete curing covers help maintain a certain level of heat and protect the concrete from colder temperatures. The covers can heat up to 110°F and trap moisture and heat, which helps accelerate the curing process.
They do this for two main reasons: to prevent moisture from the soil permeating up through a slab and into a house (also known as rising damp); and. to reduce the amount of water in the wet concrete being sucked up by the dry ground when the concrete is first poured.
Apply a concrete waterproofing sealer over the entire surface of the floor in an even layer and allow it to dry completely. Apply a second layer of concrete sealer to ensure maximum protection. Allow the sealer to dry for at least 24 hours before walking on or placing the furniture back onto the surface.
Concrete should be sealed to protect from mold and mildew.
You'll know you have mold growing on your concrete by the greenish color that appears. When you seal your concrete, you inhibit moisture from penetrating the surface and therefore prevent the development of mold and mildew.
Properly installed a vapor barrier prevents moisture from the ground from migrating to the floor joists, insulation, sub-flooring, and other materials located in a crawl space.
When properly installed and maintained, vapor barriers effectively keep off moisture and prevent mold growth. However, if not installed correctly or if they fail, vapor barriers can actually cause mold.
Vapor barriers are installed along, in, or around walls, ceilings, and floors. Of course this is done to prevent moisture from spreading and potentially causing water damage.
Most concrete contractors want a mix of coarse and fine aggregate to create a compactable base that is going to be safe for settlement and drainage. Crusher run (a mix of crushed stone and stone dust) and #57 coarse aggregate are two of the best base materials for concrete slabs.
The American Concrete Institute's Guide for Concrete Floor and Slab Construction recommends that the thickness of the vapor retarder be at least 10 mils.
Expansion material is placed between sections of concrete. It's that black stuff you see between concrete slabs sometimes if a contractor doesn't put a sealant on top of it. If they do seal it, you're likely going to see a grey sealant between sections of concrete.
Since cement lacks any natural bonding agents, newly-poured concrete won't naturally bond to the existing slab. You'll need to either use a bonding agent to adhere the two layers together or use an unbonded overlay method. Condition-affected life span: Properly installed concrete can last for over 50 years.
The good news is that you can pour the concrete in water. Professionals do this all the time. You just have a small standing puddle in your basement and that won't be a problem.