Best answer
Drill at least four holes through the slab at a point that's centered on the void beneath. ... Connect a hose to a slabjacking pump, then run the hose to the holes leading to the void. ... Mix the fill material in a wheelbarrow, using a spade. ... Fill the pump with the fill material and set it to a pressure of 10 psi.More items...
Do you need stone under a concrete slab?
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.
Can you pour concrete on 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.
How do you run a pipe under a concrete slab?
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.
How do I get rid of rats under my concrete slab?
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.
Can you run a gas line under a concrete slab?
Otherwise you could bury a pvc pipe in the concrete to run your gas line thru. Yes, you can bury the gas line. First I would bury a straight pipe larger than your gas line under the patio and then run the gas line in the pipe. If you ever need to replace the gas line it will be easy to remove.
How much does it cost to replace a sewer line under a concrete slab?
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..
Do you have to concrete chain link fence posts?
Traditionally, chain link fences are held in place by buried posts surrounded in concrete. However, it is possible to install a chain link fence without concrete. With a hole that is the proper size, either gravel or a polymer backfill can keep fence posts in place for many years.
How do you install a concrete sleeper retaining wall?
STEP 1: BASE PREPRATION. Clear and level your site where you plan to build the retaining wall. ... STEP 2: POST HOLES. ... STEP 3: AUGER HOLES. ... Step 4: Placement of Steel Posts. ... Step 5: Concrete Placement. ... Step 6: Concrete Sleeper Placement. ... Step 7: Backfill Drainage Material.
How long does quikrete concrete take to harden?
20 to 40 minutesThe concrete sets up in 20 to 40 minutes, so you can quickly move on to the next stage of the project (a great convenience when setting fence posts) or backfill the hole to finish the job. Under normal curing conditions, you can apply heavy weight to the post (a basketball backboard, for example) after just 4 hours.
How long should you wait to backfill a concrete retaining wall?
Backfilling against reinforced concrete retaining walls shall not be permitted until the concrete has reached its 28 day strength.
Related Question Answers

Matt W
ProfessorWhat can I do with an old concrete septic tank?
Interested in Septic Tanks?Remove and dispose of the tank at an approved site (normally a landfill).Crush the tank completely and backfill. The bottom must be broken to ensure it will drain water.Fill the tank with granular material or some other inert, flowable material such as concrete.

Mikael Lepistö
ProfessorDo 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.

Beshambher Chaukhwan
ProfessorHow do you waterproof a concrete slab roof?
Apply a coat of Bitu-Primer (acrylic based bituminous primer) to the concrete slab. The solvent-based bitumen primer (Bitu-Primer) is applied to the concrete slab to facilitate the correct adhesion between substrate and the Derbigum/Derbit waterproofing material.

Prasanth Bendra
ProfessorCan a concrete slab be too thick?
If the slab is too thin, it may break under load and fail before its time. If the slab is too thick, it costs more than it should. Slab thickness is a major factor in the cost of a concrete floor, so there's often pressure, which can become intense, to make the slab as thin as possible.

adeneo
ProfessorCan 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..

Squiddleton
ProfessionalHow do I find a water leak under a concrete slab?
Signs Of A Leak Under Concrete1). There is water or damp spots on your floor. If hot-water lines are leaking, this may also lead to warm spots on your floor. ... 2). You can hear the sound of rushing water underneath your floor. ... 3). There is a significant increase in your water bill.Jan 10, 2021

Rachel
ProfessionalHow do you install moisture barrier under concrete slab?
Most exterior slabs do not need a vapor barrier. ... In general, place the concrete slab directly on top of the vapor barrier, with the subbase below. ... The vapor barrier can be placed under the subbase, if the building is closed in when the dry subbase material is placed.More items...

geoand
ProfessionalDo I need mesh in my concrete slab?
Concrete is strong in compression, but not under tension. So, if it flexes, like a slab with a vehicle on top of will do, it cracks at the bottom whre the flexing becomes tension. ... Mesh will help mitigate the chances of cracking of the slab due to differential settlement.

nemo
ProfessionalHow do you lift a sunken concrete slab?
Mud Jacking is a common term for lifting sunken or settled concrete. Mud jacking can lift a settled concrete slab by pumping a grout through the concrete and pushing it up from below. The process is sometimes called “slab jacking” or “pressure grouting”.

Eng.Fouad
ProfessionalHow do you make concrete hydrophobic?
Hydrophobic cement is obtained by grinding portland cement clinker with a film-forming substance such as oleic acid in order to reduce the rate of deterioration when the cement is stored under unfavourable conditions.

Paul D. Waite
UserHow 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...

AminGolmahalle
UserCan you cement around copper pipes?
According to the Portland Cement Association the interaction of copper with both dry and wet concrete should not cause a corrosion concern. ... A screened soil/pulverized limestone mixture is recommended as a selective backfill for copper tube to help eliminate corrosion concerns.

sudo bangbang
UserCan you use spray foam under concrete slab?
Insulating under foundation and basement slabs using SPF (spray polyurethane foam) offers certain advantages over the more common method of using rigid foam board. ... Two-pound foam. Only closed-cell SPF can be used in a subslab installation; the open-cell foam does not have adequate compressive strength.

Jakuje
UserDo you put cement board under bathtub?
You don't need any cement board under the tub. It is far more important to have a sturdy layer of ply under the tub.

paradocslover
UserHow do you break concrete slab?
With small slabs of concrete, such as patio squares or air conditioner pads, you can also have one person pry up the slab a few inches, using a demolition bar, while another person strikes the slab with the hammer. Prying up the slab has the same effect as digging underneath it.

Set
GuestHow 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.

Anonymous
GuestCan 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.

leerssej
GuestCan 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.

Tony Suffolk 66
GuestHow much insulation do I need under a concrete floor?
A 50mm thick layer of proprietary floor slab insulation is usually enough to reach and maintain the target U value but this should be checked with an architect first. Insulation sheets should be laid tightly together with the joints staggered to avoid movement.

Tom
GuestWhat 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.

sawa
GuestWill 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.

Roophie
GuestWhat is the primary purpose of the plastic membrane placed under a concrete slab on ground?
The main purpose of under-floor waterproofing membrane is to prevent rising damp from entering concrete or other floor surfaces. In addition it prevents contamination of concrete during the pouring process.

Alien
GuestHow do you break concrete slab by hand?
InstructionsDig Under the Concrete. Dig out the soil, gravel, or other material from under the concrete, using a shovel and a pickax. ... Strike the Concrete. Lightly sprinkle the concrete with water to minimize dust. ... Pry Off Stubborn Pieces. ... Move the Concrete Chunks With a Hand Truck.Feb 19, 2020

Jim Puls
GuestDo I need concrete reinforcing mesh?
And yes, mesh is important: Concrete is strong in compression, but not under tension. So, if it flexes, like a slab with a vehicle on top of will do, it cracks at the bottom whre the flexing becomes tension. Steel mesh will prevent this to a large degree and hold it all together.

DK.
GuestCan concrete cure underwater?
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.

Kyle
GuestCan 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.

Utshaw
GuestCan 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.

emmby
GuestCan 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.

Justin Ethier
GuestDo 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.

Kuberchaun
GuestDo you need gravel under a concrete patio?
Yes! A strong gravel base is required when building a concrete patio in order to prevent the concrete from shifting or cracking. Adding gravel under the concrete also provides a level surface for your foundation and adds proper drainage when there is pooling water.

Adriano Repetti
GuestDo 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).

breq
GuestHow do you destroy a concrete septic tank?
Remove and dispose of the tank at an approved site (normally a landfill). Crush the tank completely and backfill. The bottom must be broken to ensure it will drain water. Fill the tank with granular material or some other inert, flowable material such as concrete.

John Millikin
GuestDo 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.

pveentjer
GuestHow do I remove concrete from my lawn?
Steps for Removing a Concrete SlabStep 1: Create a Void Under the Concrete. The best way to speed up concrete removal is to create a void underneath the section of slab you're working on. ... Step 2: It's Hammer Time. ... Step 3: Pull Apart and Remove the Broken Concrete. ... Step 4: Repeat Steps Until Concrete Is Demolished.Jan 16, 2019

doniyor
GuestHow do you break concrete at home?
InstructionsCover the concrete slab with 4 mil plastic sheeting if you're working near windows.Dig under the concrete if you're able to do so.Start to break the concrete, starting six inches from the edge and working your way in. ... Pry with a long bar or wrecking bar as you go. ... Cut any mesh wire with bolt cutters.More items...•Oct 14, 2019

thdoan
GuestHow do you remove concrete topping?
This is easily done by prying up the concrete from underneath and breaking it into smaller pieces.
Use a flat scraper with a long handle to drive under the overlay and lift up.
A small block of wood under the handle near the blade will act as a fulcrum for more leverage to lift up the concrete pieces..

Ben
GuestHow many inches of gravel do you need for a concrete slab?
Excavate the slab area to a depth of about 7 inches, allowing 3 inches for a gravel base and 4 inches for concrete.

Tom
GuestHow many bags of concrete do I need for a 12x12 slab?
Enter the size of the slab you want to build in square feet. The calculator will indicate the number of 60 or 80 pound bags of QUIKRETE® Concrete Mix you need to build a 4″ or a 6″ slab. (All yields are approximate and do not include allowance for uneven subgrade, waste, etc.)

Miq
GuestWhat 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.

xgqfrms
GuestDo 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..

ducin
GuestDo you have to cement chain link fence posts?
Traditionally, chain link fences are held in place by buried posts surrounded in concrete.
However, it is possible to install a chain link fence without concrete.
With a hole that is the proper size, either gravel or a polymer backfill can keep fence posts in place for many years..

Mads Hansen
GuestHow do you break concrete by hand?
InstructionsDig Under the Concrete. Dig out the soil, gravel, or other material from under the concrete, using a shovel and a pickax. ... Strike the Concrete. Lightly sprinkle the concrete with water to minimize dust. ... Pry Off Stubborn Pieces. ... Move the Concrete Chunks With a Hand Truck.

F_SO_K
GuestShould you caulk concrete expansion joints?
Even expansion joints in your concrete driveway should be caulked. They can be the biggest culprit of water under your slabs. Notice how the caulking is slightly lower than the concrete slab around it. This protects the caulk from wear and tear of people walking and driving over it.

James McMahon
GuestShould 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.

avdeluca
GuestHow much does a 24x30 concrete slab cost?
On average, the material alone costs anywhere between $5.38 to $6.19 per square foot. How do you calculate concrete for a slab?...How much does a 24x30 concrete slab cost?Concrete Slabs CostsZip CodeBasicBestConcrete Slabs – Total Average Cost per square foot$6.88$14.612 more rows•Apr 16, 2020

Pithikos
GuestWhat 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.

Veedrac
GuestHow thick should a concrete porch be?
4 inchesWe generally try to maintain a minimum thickness of any slab at 4 inches, if the patio will have heavy features added on it, you may want to thicken it to 6 or even 8 inches, at least under the area where the feature will be added..

daniel
GuestHow thick should concrete floor insulation be?
Designers generally insulate both directly under the slab and around the perimeter as well. In cold climates it is advisable to use a minimum of 2 inches of extruded polystyrene under the slab. Many increase the under-slab insulating foam board thickness to 3 or 4 inches at the outer 2 to 4 feet of the slab.

Alumno Cabreado
GuestWill concrete cure in 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.

Inbar Gazit
GuestHow do I get rid of snakes under my concrete porch?
Snake Under a Shed, or Under the House, Deck, or PorchCall a pro: The best way to get rid of snakes under a house or other building is to hire a professional, especially if it is large or poisonous. ... Trim plants: ... Instal a snake fence around the perimeter of the shed: ... Use repellents? ... A dog or cat: ... Rodent control under the house: