What Size Gravel Under Concrete Slab

Importance of Gravel and Sand for Concrete | Hunker

Importance of Gravel and Sand for Concrete By Deborah Ng| April 12, 2018 A typical concrete mix contains 60 to 80 percent sand and gravel, also known as an "aggregate" This aggregate compound is more than filler It plays an important part in the concrete's composition

Choosing Best Gravel For Concrete Pad - Concrete & Paving

Jan 06, 2008 · Re: Choosing Best Gravel For Concrete Pad does 3/4 mean 3/4" and 57 (or 5/7?) mean 5 to 7 cm stone? I compact it all the same, but doesn't seem to do a whole lot except aroudn the edges

Gravel under Concrete Slab | Pilots of America

Jun 28, 2016 · Seems to me its better to put my money into thicker concrete and rebar (to span cracks and keep them from becoming "steps") but I dunno for sure My concrete conctractor wants to put 2" of gravel under there and I dont see any reason to spend the money when we have the filldirt onsite

Gravel Size Under Concrete Slab– Rock Crusher Mill-Rock

Gravel Size Under Concrete Slab XSM is a leading global manufacturer of crushing and milling equipment (Gravel Size Under Concrete Slab),XSM also supply individual (Gravel Size Under Concrete Slab) crushers and mills as well as spare parts of them

compacting gravel under a slab - JLC-Online Forums

Dec 07, 2004 · Re: compacting gravel under a slab Dick Siebert The reason that a graded granular material compacts better than a uniform material such as stone is that with a graded material the different sized particles interlock with each other so if you compact it to 100% proctor density it has no where to go, it locks in solid

gravel under concrete slab? is it absolutely required

gravel under concrete slab? is it absolutely required? Ask Question 4 and it will be a thinner slab I could put gravel in, say 2" and 35" of concrete over that or just full 55" of crete or I could do lot of gravel and a 2" top coat over that with a bunch of steel and fibers, but I dont think its enough At the end of the day, it is

Gravel under concrete footing - GreenBuildingAdvisor

Gravel under concrete footing Timothy Denny | Posted in Energy Efficiency and Durability on April 1, 2015 12:08pm I am trying to finalize several aspects of the foundation design for the high-performance house we’ll be building in central Vermont starting in May

The Recommended Gravel Base for a Concrete Driveway

A layer of gravel placed between the soil and the concrete slab prevents damage from shifting and heaving and increases the weight-bearing capacity of the driveway

Compact Fill Under Slab - Ask the Builder

Compact Fill Under Slab - Concrete bends and breaks Use self-compacting fill Water helps compact Concrete block ledges on footer This gravel is the size of small green peas and it naturally compacts as it's put into a void space Visit a few local gravel pits in your area to see if they have this small rounded gravel

Ask the Builder | Concrete slab needs quality self

It will ensure the slab will not separate, with one part being higher or lower than another part Steel is concrete’s best friend, as it add enormous tensile strength to concrete slabs

Compact Fill Under Slab - Ask the Builder

One option is to lay concrete block up off the interior ledge of the footers to just below where the concrete slab will be These can be spaced at 4-foot intervals around the interior foundation walls The concrete slab will rest on these and provide solid support down to the footer

Subgrades & Subbases for Concrete Slabs - The Concrete Network

If the subgrade settles under the middle of the slab or at the edges, the unsupported portion can lead to cracks or slab failure So if we aren't counting on the steel to carry any load, then the concrete has to be strong enough to carry the bending

compacting gravel under a slab - JLC-Online Forums

Jan 10, 2005 · Re: compacting gravel under a slab yeah, I was thinking about that too But #4's are about 70 cents a foot around here so if add that ( at 12 inches on center) to the cost of fill and a six inch slab (as was recommended and probably a good idea) than I'm looking at …

Proper Subgrade Prep| Concrete Construction Magazine

The top 6 to 12 inches of the backfill under the slab should be filled and compacted with well-graded gravel or crushed material “Walls are typically backfilled with the removed earth or with a granular, open-graded material,” says Tull

Shed Base: Concrete Slab or Gravel? | DoItYourself

The gravel is easier to remove and move than tearing up a concrete slab What do local zoning and building ordinances say? Some locales consider any building, no matter how small or large, to be a permanent structure if it is erected on a concrete slab

why is it important to have gravel under a concrete slab

Mar 24, 2010 · If you are just pouring a Slab without footings it is very important that you have firmly packed gravel, 4-6" and then about 6" of 3/4 stone, the 3/4 stone will allow the slab to float, and move, rather than crack when the gravel shifts Loading

gravel or crushed stone under concrete | Mobile Crushers

» gravel or crushed stone under concrete 3/8" Pea Gravel Used for landscaping, trim areas, radon rock under foundations and fine granding under concrete slabs

How much gravel under a slab? - tractorbynet

Sep 10, 2002 · On the concrete, are you saying that ordering concrete by the yard on the truck will compact down 20% as well I did not realize that or really think that I don't think I'd use compacted gravel under a slab Maybe for a base, but then I'd put 4" of compacted sand on that Sand has more particles of the same relative size than gravel does

Deep Fill Under Garage Slab - Masonry - Contractor Talk

Aug 03, 2014 · One reason that comes to my mind,the concrete coverage of the steel placed in the slab The steel should have a minimum of 2" of coverage however …

Pea gravel for interior floor slab support - Geotechnical

Jun 06, 2006 · Pea gravel is still commonly used under floor slabs and tight places Floor contractors don't like working with it because it displaces so easily under foot and while placing concrete Many contractors in the Puget Sound region have opted for clean, crushed rock such as 5/8"

How to Calculate Concrete Needed To Pour a Slab | Hunker

Hence, a little conversion table is a useful thing to have on hand Remember: 1 cubic yard equals 27 cubic feet, which equals 46,656 cubic inches That means a 80-pound bag of concrete mix will yield 06 cubic feet of concrete, a 60-pound bag will yield 045 cubic feet and a 40-pound bag yields 03 cubic feet

Polyethylene Under Concrete Slabs - GreenBuildingAdvisor

What goes under the concrete in a slab-on-grade home? In the old days, not much — just dirt Eventually, contractors discovered that it made sense to include a 4-inch-thick layer of …

How important is gravel under a concrete sidewalk? (Home

Ask Your Question Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers How important is gravel under a concrete sidewalk? 3-4 inches excavation (so top of slab is still just above ground level) and graded to drain water to edges and

Placing a Small Concrete Slab - Fine Homebuilding

7) Screed the slab Flatten the concrete using a straight 2×4 that’s about 1 ft longer than the form width Move the board forward with a back-and-forth sawing motion while keeping it on the form 8) Tamp the surface with a rake Gently tamp the entire surface of the slab The rake pushes down the gravel that’s part of the concrete mix

What Size Gravel To Use Under Concrete Pad - Building

May 09, 2011 · Approx numbers: 340 cubic feet 21,760 lbs 1813 pounds/sqr ft I think you'd be safe w/ a steel reinforced 4" slab, and if you go to 6" with only one layer of steel, you may be wasting 2" of concrete

How important is gravel under a concrete sidewalk? (Home

2 Answers Should typically (for sidewalk NOT being driven on by cars or large yard tractor) 3-4 inches excavation (so top of slab is still just above ground level) and graded to drain water to edges and downslope to an exit point (or several) so water can't get trapped underneath, well compacted

Do you need to put gravel under a concrete pad? | Yahoo

May 12, 2008 · Answers It helps with the drainage, and also with the settling of the concrete, so the cracks are minimal You want 4 inches of gravel under 4 inches of concrete Any less concrete and you will have problems in the near future Dig down 8 inches in your backyard the size of the pad you are pouring Put 4 inches of gravel in and smooth

Gravel under Concrete Slab - Turtlesoft

add for gravel under Concrete estimating unit cost for installation of gravel under a concrete slab One square foot We figure one unskilled hour per 33 square feet of area, plus one skilled or supervisor hour per 250 square feet The time includes placement, leveling and compacting with a power tamper

Do I need gravel under concrete patio and sidewalks? Do I

Gravel is bombproof when used properly what your going to want to do is mark with spray paint were you concerte is going to be, dig a trench 150 mm deep were your concrete is going to be next fill the open trench with roughly 150 mm of 20 mm gravel, soak the gravel …

Placing a Small Concrete Slab - Fine Homebuilding

Choosing concrete For a slab that’s 40 sq ft or more (about 1/2 cu yd of concrete for a typical 4-in-thick slab), it’s easiest to order truck-mixed concrete This 3-ft-sq slab was small enough that mixing bagged concrete by hand made sense At 9 sq ft and 4 in thick, the project called for 3 cu ft of concrete An 80-lb

best size stone for under concrete slab - educationcare

Whether you pour concrete for a walkway or patio, a strong gravel base is well, which results in water pooling under the concrete slab and slowly eroding the soil as it finally drains The gravel should contain gravel dust, which binds the stones further

Why Put gravel under concrete? - Google Groups

May 06, 2010 · Coarse gravel, like 57 stone, under a slab is used as a capillary break to prevent ground moisture wicking up through the concrete All good concrete needs the bottom almost as flat as the top, creating a uniform thickness to maximize strength

Stone, Gravel, or Aggregate?| Concrete Construction

Question: I have a specification calling for #89 gravel in the concrete mix and #57 stone for the subbase What do these numbers mean? Answer: This all comes from ASTM C 33, “Standard Specification for Concrete Aggregates” First, there's really no difference in …

Concrete slab for water tank - Renovate Forum

Jun 04, 2007 · Slab size about 1500 x 1000 Tank size 1000L Since water is about 1kg to the litre, would a crushed rock base of 50mm, and 50mm concrete do? Or should I increase concrete to 100mm? Area can be ocassionally wet (under eaves but receives a hammer of rain now and then) Lastly, what point/size/thickness (forgotton the term) reo should I be using?

Sand under slab instead of gravel - GreenBuildingTalk

Mar 04, 2013 · Sand under slab instead of gravel Last Post 04 Mar 2013 08:14 PM by jessie 7 Replies Sort: Prev Next: You are not authorized to post a reply Just to be clear, a layer of plastic solves the issues with sand under the slab Ie, sand, plastic, concrete is OK except that it doesn't provide for radon removal (which may not be a problem in

How To Pour A Concrete Slab For A Shed - Zacs Garden

This is how to pour a concrete slab for a shed, taken from my recent slab pour - with pictures ordering concrete from a mini-mix comes in a minimum of 1 cubic meter The size of my slab is approx 34m x 23m and the easiest way to do this is ‘bar chairs' You could also get some old bricks or something else concrete and put them

Quality Concrete Slab Design - gpsinformationorg

This checklist will help you get the quality concrete slab floor you are looking for A good motto to remember is: A well INSPECTED job is necessary to get the job you EXPECT (gravel) under the concrete and on top of the footing lip However, some crews may dig down 4 inches below the footing lip, and put in four inches of aggregate to

Concrete Slab Insulation - reflectixinc

Under a Concrete Slab: 1) Unroll Reflectix ® Concrete Slab Insulation over the sand or gravel, (white poly side up) 2) Butt the seams 3) Seal the seams with 3” wide poly tape All tape should be applied using a flat edge taping tool to assure good adhesion