Best answer

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.

Answered by: Andrew Morton Date created: Jun 26, 2022

Do you need stone under a concrete slab?

Asked By: Prophet Date created: Jun 24, 2022

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.

Answered By: Wesley Smith Date created: Jun 24, 2022

Can you put dry concrete in a post hole?

Asked By: WhiteFang34 Date created: Jun 18, 2022

Fast-setting concrete is ideal for setting posts because there's no mixing—you simply pour the dry concrete from the bag right into the hole, then add water. ... Under normal curing conditions, you can apply heavy weight to the post (a basketball backboard, for example) after just 4 hours.

Answered By: Glorellia Date created: Jun 20, 2022

Can you pour concrete on clay?

Asked By: Onik Date created: Jun 23, 2022

Unfortunately, if you have clay-heavy soil, then you may run into difficulty when pouring a slab. The clay can compress under the weight of the concrete, causing the slab to shift or sink over time. With proper preparation, however, it's possible to pour a slab on clay soil without encountering these problems.

Answered By: noob Date created: Jun 25, 2022

Are concrete roof tiles heavier than clay?

Asked By: Hemerson Varela Date created: Jun 15, 2022

Concrete tiles are already heavier than clay and the roof underlay is put under extra pressure due to the presence of water.

Answered By: ypercubeᵀᴹ Date created: Jun 16, 2022

Can you put cement in wet ground?

Asked By: Lior Bar-On Date created: Jun 10, 2022

The water in the hole under the pipe can be sucked out with a wet-dry vacuum before and during the repair job.

Answered By: Will Keeling Date created: Jun 12, 2022

How do you run a pipe under a concrete slab?

Asked By: Lars Kotthoff Date created: Jun 13, 2022

In six simple steps you can dig under concrete:Attach drill pipe.Connect garden hose.Dig a small ditch.Start your bore.Add more drill pipe (if necessary).Pull piping through.

Answered By: BelHadjSalem TALEL Date created: Jun 14, 2022

How do you termite proof a concrete slab?

Asked By: Renshaw Date created: Jun 09, 2022

To make a concrete slab as termite proof as possible, it is best to use a combination of both physical and chemical barriers to augment its strength. While a builder will be able to put physical barriers in place, chemical barriers can only be installed by licensed pest controllers.

Answered By: PaulMcKenzie Date created: Jun 11, 2022

How do I get rid of rats under my concrete slab?

Asked By: Michael Jungo Date created: Jun 23, 2022

Answer: If the patio slab is not connected to the house slab you can use a Giant Destroyer to help eliminate the rat. If there are many tunnels or if it is in an area where you cannot seal up the entrances you may want to consider using rat poison baits instead such as Fastrac or Contrac.

Answered By: Andreas Date created: Jun 25, 2022

Should concrete patio be attached to foundation?

Asked By: Fedor Date created: Jun 12, 2022

No, dont attach the slab to the house. Unless you put down a foundation, the slab will rise and fall with 'frost freeze'.. And, it 'will' crack your foundation.

Answered By: Allan Chain Date created: Jun 14, 2022

How much does it cost to replace a sewer line under a concrete slab?

Asked By: Fabio Date created: Jun 16, 2022

The cost to replace a sewer line under a slab costs $3,000 to $5,000 for smaller jobs and $15,000 to $20,000 total for larger jobs.

Trenching under a slab can cost an extra $150 to $200 per foot..

Answered By: bgporter Date created: Jun 19, 2022

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What is the best flooring to put on a concrete floor?

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Do you need to put a vapor barrier behind cement board?

You should NOT place a vapor barrier BEHIND the backer board. Where, pray tell, would any such collected vapor/water go? Answer:There's nowhere proper for such moisture to egress. The current best practice is to place waterproofing OVER the backetboard and just UNDER the tile.

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Do you put cement board under a shower pan?

Once the subfloor of proper thickness is properly installed then you can apply cement board directly to the subfloor material. ALL CEMENT BOARDS MUST be installed in a fresh bed of thinset. ... If you want the cement board under the shower tray then do so - doesn't matter.

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Can concrete cure under water?

Water Cure Concrete made with Portland cement will harden even if it is completely under water.

In fact, one technique for curing a concrete slab is to build a soil dam around the perimeter of the slab, flood the slab with water and keep the slab covered with water for a week..

StupidWolf

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Can I put cement over cement?

Yes, you may pour a concrete pad overlay over an existing slab. You need to consider the added height and weight of the overlay on the existing structure. Overlays may include polymers, portland cement concrete, or epoxies. You should improve the drainage of the slab by having a good slope on the overlay.

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Can you put ceramic tile over concrete outside?

For an outdoor tile patio installation to be successful, it needs a solid base, and a concrete slab is an excellent choice. ... If you already have a slab in place, that will save you some work. But before you can start tiling over this base, you need to examine it more closely.

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How do I find a water leak under a concrete slab?

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How do you install moisture barrier under concrete slab?

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Do I need mesh in my concrete slab?

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How do you run a conduit under a concrete slab?

Select a pipe of sufficient diameter for the desired excavation width. ... Dig a small trench on each side of the concrete slab. ... Measure the width of the concrete slab. ... Push the angled end of the PVC pipe into the soil in the trench on one side. ... Tap the other end of the PVC pipe with your sledge hammer.More items...

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User

What type of insulation goes under concrete slab?

Two of the rigid foam insulations most commonly used below grade and under slabs are expanded polystyrene (EPS) and extruded polystyrene (XPS). Although both are closed cell insulations, they perform very differently over the long term.

Keet Sugathadasa

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Can you put ceramic tile on concrete basement floor?

A: It's perfectly acceptable to put tile directly on concrete — with a couple of caveats. First, it is important to determine if there is moisture coming up from the slab. You can test for moisture by taping all four sides of 18-by-18-inch polyurethane plastic on the slab.

Ohgodwhy

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Can you run water pipes in a concrete floor?

During the initial building of a home that has a concrete slab foundation and basement level, any plumbing that runs under the home must be put in before the concrete is poured, since the plumbing runs in the dirt, not within the actual concrete.

rene

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How do you fix a void on a concrete slab?

– Sand-Cement Grout A sand-cement grout can be used to fill voids under concrete slabs. This mix of sand, cement, and water is pumped through holes drilled to fill up the voids. While this method of slab jacking is cost-effective, there are major drawbacks to opting for this type of repair.

Hossein Azizdokht

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Can water go under concrete slab?

Weakened water lines. Since water lines are laid down under the concrete slab, there can be minor damage such as small nicks when the concrete is poured. Although these occurrences may not cause immediate leaks, they can weaken the pipes and grow into a leak-causing crack later.

Adam Rosenfield

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Can you put footings under concrete slab?

edit - To put footings under the slab, you can cut holes wherever needed, excavate for footings (Sonotubes or concrete piers or similar) and then patch the concrete slab.

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Do you have to put Thinset under cement board?

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Kelly

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What is the best insulation for under a concrete slab?

Applying a bead of polystyrene-compatible caulk or mastic to the top of the insulation board minimizes water infiltration behind it. For under-slab applications, the rigid foam insulation typically should be installed over a gravel base, with a poly vapor diffusion retarder between the gravel and insulation.

Ben Reiniger

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What do you put under a concrete driveway?

Use wire mesh for driveways that are 4 to 5 inches thick, and rebar for those that are 5 inches or more. Place rebar in a grid pattern with a spacing between bars of approximately 12 inches. In either case, blocks should be used under the reinforcement to keep centered within the concrete.

UnkwnTech

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What do you put under concrete blocks?

To create the base, spread a 4-inch layer of gravel over the excavated area. Level the gravel, following the initial grade, and cover it with a 1-inch layer of sand. Tamp the gravel and sand down with a plate compacter before laying the blocks.

murtaza52

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Why do people put plastic sheets on concrete roads?

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What happens if you pour concrete without rebar?

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How do you put concrete under water?

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How do you backfill under a concrete slab?

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rouble

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How thick does a concrete slab need to be?

six (6) inchesIt is essential that you keep your concrete slab at no more than six (6) inches of thickness. Also, it would be best to work the numbers out if you wish to work with any lesser as you can only put in one slab.

stivlo

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What is a concrete rat slab?

Rat slab also called mud slab is a few inches layer which constructors put on the foundation. Rat slab is a thin layer of some concrete poured over the floor or your crawlspace. It is a fine, poorly finished area that is not at a very smooth level.

ggorlen

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What is the purpose of a vapor barrier under concrete slab?

The use of a vapor barrier (more accurately termed a vapor retarder), having a water vapor permeance of less than 0.3 perm is frequently used to retard the flow of moisture through the slab. These vapor retarders are typically polyethylene or polyolefin sheeting materials.

RedBlueThing

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What animal would burrow under a concrete slab?

Rats, mice, moles, voles, gophers, and several other types of ground-burrowing rodents are natural diggers, constantly seeking out shelter and sources of food. Sometimes, they choose to make their dwelling space underneath concrete foundations.

boulder_ruby

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What happens when you pour concrete over grass?

You should not pour concrete over the grass directly. For your concrete to harden flat and smooth, it is best to clear all vegetation and pour the concrete on top of smooth and debris-free soil. Leaving grass under your concrete slab can cause some unnecessary issues for you in the future.

rampion

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What is the best flooring to put over a concrete slab?

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Will concrete cure under water?

Water Cure Concrete made with Portland cement will harden even if it is completely under water. In fact, one technique for curing a concrete slab is to build a soil dam around the perimeter of the slab, flood the slab with water and keep the slab covered with water for a week.

kapa

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Do I need DPM on concrete floor?

Do I need a DPM under laminate flooring? Simply put yes. In order to prevent damp rising through the concrete floor and causing issues, a DPM should be used under all final floor types including wood flooring, laminate, vinyl and floor tiles.

Kevin Meredith

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How do you break concrete slab by hand?

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willcodejavaforfood

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Can you add footers to a concrete slab?

edit - To put footings under the slab, you can cut holes wherever needed, excavate for footings (Sonotubes or concrete piers or similar) and then patch the concrete slab.

Yevgeniy Afanasyev

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Can you pour concrete on soft ground?

If you drive over a concrete slab that's got soft ground under it, the concrete wants to bend and stretch. ... If the concrete does develop a hairline crack, the crack should not open with the steel in place. Compacting the soil under the slab before the pour also prevents tension cracking.

Mike 'Pomax' Kamermans

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Can you pour concrete on top of clay?

Unfortunately, if you have clay-heavy soil, then you may run into difficulty when pouring a slab. The clay can compress under the weight of the concrete, causing the slab to shift or sink over time. ... With proper preparation, however, it's possible to pour a slab on clay soil without encountering these problems.

Chris B.

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Do you need a vapor barrier under concrete driveway?

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.

pawello2222

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Do you need to reinforce concrete slab?

Concrete is an incredibly resilient material, which is why it's used so much in building and construction work. However, some types of concrete structure require reinforcements, which are often put in place as the mixture sets.

quervernetzt

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Do you put plastic under concrete slab?

In California they place sand between slabs and plastic vapor barriers—in Florida they don't. Almost everywhere (except “California”) that slabs are placed on the ground—a plastic sheet—a vapor barrier—is located directly under the concrete slab and on top of the ground (Photograph 1).

Prafull Ladha

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Do you need sand under concrete slab?

One reason it is used as a backfill or sub-grade material. As with all material, it has to be placed correctly and compacted properly. Sand needs to remain damp as well as other material before placement of the concrete. If you want to build a road, use gravel, but this does not mean you will not have issues.

Green Cloak Guy

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Do you need to put wire in a concrete driveway?

Wire mesh, like Rebar reduced the cracking and any uplift in the concrete driveway. Rebar will be used if there is a structural reason, meaning you need to carry the weight of the slab to pilings or plan to build above the slab. For a driveway, just use the wire, lap it one box around.

Kiv

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How do you break concrete at home?

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Dmitriusan

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Do you have to put cement board under tile?

In short, tile and grout are not inherently waterproof. ... Cement backer board is often used as a tile base on plywood or OSB subfloor. Cement backer board on concrete as a subfloor or underlayment is usually not recommended or needed. In most cases, you can apply tile directly to the concrete.

karim79

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What happens if you pour concrete on dirt?

The clay can compress under the weight of the concrete, causing the slab to shift or sink over time. It also can leach moisture from the concrete itself, resulting in uneven curing and a brittle base. With proper preparation, however, it's possible to pour a slab on clay soil without encountering these problems.

person_v1.32

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Do I need gravel under my concrete slab?

Whether you pour concrete for a walkway or patio, a strong gravel base is required to prevent the concrete from cracking and shifting.

Gravel is especially important in clay soil because it doesn't drain well, which results in water pooling under the concrete slab and slowly eroding the soil as it finally drains..

Erwin Kalvelagen

Guest

Should you put plastic under concrete slab?

Recently, though, research has shown that the old traditional layer of 6-mil Visqueen (polyethylene plastic) under the slab is seldom effective for two main reasons: Although it may seem water-tight, this grade of material allows a lot of water vapor to pass through.

mrsrinivas

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What is the purpose of plastic sheeting under a concrete slab?

The sand layer cannot dry downwards by vapor diffusion because of the plastic sheet—it is a vapor barrier after all. In fact that's why we have it under the slab. We want a vapor barrier under the slab. ** We want to prevent water vapor from coming up from the ground into the concrete slab.