Fo r decades ACI 318 has re q u i r ed high- Concrete slab-on-ground floors shall be designed and constructed in accordance with the provisions of ACI 332 and this section. Draw also the typical beam detail showing the main. 1. There are many variables that influence the decision of how much space to leave, including the maximum load the slab is likely to. Tie the rebar together. ) is going to be 5'-6' for 4 ksi concrete anyways. Wood blocks should never be used for this purpose. #Lonbicooltv Using the search function should turn up a lot of info. Specify the spacings: rebar-rebar spacing = 40 cm, edge-grid spacing = 8 cm. 9836 m 2 Area of openings (lift and staircase) = 18. 1 Spacing s of transverse reinforcement in cast-in-place walls shall not exceed the lesser of 3h and 18 inches. Map rebar and rebar patterns. 6 of the International Building Code. e. long-term deflections of the slabs. Commonly called “rebar,” these 1/2-inch-diameter steel rods are embedded in the center of the slab to create a grid that extends lengthwise and crosswise to help the concrete better resist pulling and bending forces. x 20 in. Development length = 40d. Post-tension cables. I recommend use of M20 grade of concrete. Often, concrete contractors don’t have solid runs of rebar anyway. Thank ForSubscribeLikesShare. The support for reinforcing steel in floor slabs is shown in figure 7-24. A good compacted base below the concrete is equally important. 10) Deflection and end-slip behavior. Mesh is set on chairs and placed over the entire floor area 1 to 2 inches above the top of the forms. SLAB BOLSTER—Continuous bar support used to support bottom slab bars. 73 per square foot, with an average cost of $6. When arranging joints, skilled contractors will often use them to create an attractive diamond pattern. Corner angle. After pouring concrete walls, they are anywhere from 8 to 10 inches thick. Use f’c = 28 MPa and fy = 414 MPa for main rebars and fy = 276 MPa for shear reinforcement. Next, you put steel rebar every 2 feet to strengthen the bond between the foundation and the footings. 5 round bars, respectively, while. A residential post-tensioned concrete slab will typically be 8 inches thick and use 3000 psi concrete. Most homeowners can expect to pay between $4. Reinforcing bars that are spaced too far apart could result in relatively large flexural crack widths. 3 For long, narrow panels, place rebar at 0. vapor retarders - some times referred to as vapor barriers, insulation, etc. Such applications usually involve the placement of large numbers of bars with close spacing. This is illustrated in Figure 1, where #5 bars are used in both the top (T) and bottom (B) layers in T wo-way slabs are generally defined as suspended slabs where the ratio of the long to the short side of a slab panel is 2 or less. Rebar Grid Calculator. For the purpose of analysis and design, a unit of the slab is cut out at right angles to the supporting beams, shown in Figure-2, which may be considered as a rectangular beam. rebar spacing o. 50 m span joist, beams, & girder soffit under 3. There are two types of Grade slabs: Usually after casting Plinth beams. For multi sided slab, first draw the shape: 1: Hit Clear + Start and enter Side Length of first side to draw, then hit appropriate direction (Arrow) button to draw. The spacing of the main steel in a slab should not exceed the following:First, the American Concrete Institute (ACI) Residential Code Requirements for Structural Concrete (ACI 332-14) requires contraction joints and provides a table to determine joint spacing for plain and reinforced concrete containing up to 0. 5” long, are typically dosed at the rate of 60-68 pounds per cubic yard. Rebar, or reinforced steel poles, are a vital structural element of a pool. 120 m Length of shorter side of building = 12. Floor slabs can range from a simple residential basement slab to a heavy-duty industrial floor. First, Get The Number Of Required Bars. For corrosion protection, however, most specifications require a minimum depth of concrete cover that usually ranges from 1 inch to 2 inches. I’m on the second floor and the floor is 6 inch concrete slab with I think at least 1 inch steel rebar as reinforcement. To se-lect the appropriate steel area (As), use theFor example, if both slabs have rebar mats that are spaced at 18 inches and use No. 1 -The no. D bar or 10 mm if you are using Plain bars. If two or more courts are constru c t e d , expansion joints should be prov i d e d midway between court s. Design Rules - Footing/Pile Cap Rebar. 4. Because of this, the Building Code places limitations on the size and spacing of rebar in gunite & shotcrete. Generally, for a standard residential foundation, the minimum spacing between rebar should be at least 4 inches. 2): where f s is the calculated stress in the flexural reinforcement closest to the tension face of the section. INSTRUCTIONS: Choose units and enter the following: ( L) Length of the slab. 3. Joints are commonly spaced at distances equal to 24 to 30 times the slab thickness. It says that floor slabs were patent designs back in the 1920's. Purpose. You'd really need to know how much steel was in it to get solid data. rebar strength is in tension, so by adding rebar to BOTTOM of foundation, it counter acts the load of compression. 23 Total factored load = 6. The design of slabs for imposed loads and live loads is based on the type of the building. for 500 MPa reinforcement it must be either 500PLUS® Rebar (Class N) or OneMesh500™ (Class L). 8. Compressible floor-covering materials that compress more than 1/ 32 inch (0. Minimum clear cover to reinforcements in slab depends on the. The typical depth for rebar placement for slabs is 2-4 inches. Compressible floor-covering materials that compress more than 1 / 32 inch (0. . The no. 9836 – 18. If the floor is designed as a reinforced-concrete slab requiring rebar in the tension zone, the designer should specify the correct rebar position. Slab may be supported on walls or beams or columns. x 20 in. Spacing of mechanical shear transferring devices, s, where variable from one profile to another; and . Fabrication of rebars consists of cutting to length and required bending. 5, which correspond to diameters of 3/8-inch, 1/2-inch, and 5/8-inch, respectively. Fill in the price and single rebar length that you will buy at your supplier: rebar price = €2/m single rebar length = 6 m. e. Step 1. Place these positioners at a spacing that will not allow the rebar to bend or deflect enough to reduce the coverage you wish to obtain with the concrete you place in you forms. The first step in getting reinforcement design for an elevated slab floor is defining design strip rules. diameter) for a house construction are not that many. The splices should have at least 2 ft overlap into the new pour. ICF Foundation and One ICF Story – The sequencing here is to build the foundation walls first, place concrete, and then build the above-grade walls second. The top of the wall will need "hooks" in the rebar in order to fasten the wall to the garage slab. The elevation to the top of the decking (bottom of the concrete waffle slab) for forming of the second floor above-grade slab is ___. 5 kPa), column spacing typicallyRepeat this process until you’ve laid all the necessary rebar. Part of the building is 2 storeys high. In inches the diameter of a #5 rebar is 5/8″ and that of a #4 rebar is 1/2″. 2. 1. ASCE, SECB COURSE CONTENT Slab on Grades Construction: Introduction Concrete slabs on grade are a very common type of concrete construction. extension of existing reinforced concrete (R/C) structural elements such as slabs, walls, and columns (Figure 3), either to facilitate expansion of floor space or to address other functional changes in the use of the structure. on center, but this will depend on the structural design. Construction joints also have this spacing for strip placement of the concrete. . For slabs of septic tanks, you usually use #3 and #4 bars. 7. 2. 87 d Spacing of bar = Design of Continuous Slab Suppose a slab is supported at the ends and also at intermediate points on beams, the maximum sagging and hogging moments to which the slab is subjected to due to uniformly distributed load, can be computed as follows: Let = intensity of dead load per square metre. 5 meters and the support beams are basically 18 x 18 inch reinforced concrete beams that are really strong. e. 15 mm) polyethylene vapor retarder with joints lapped not less than 6 inches (152 mm) shall be placed between the base course or subgrade and the concrete. The height of the slab bolster is determined by the required concrete protective cover. For example, one-way slab thickness. As ready-mix trucks arrive. g. Placing the rebar at the bottom of the slab will provide no benefit to the concrete. With some limitations, reinforcement for slabs can be sized using the Subgrade Drag Theory in order to increase the spacing of control or construction joints. It has Spanish language descriptions, labels and diagrams and it also has default units in the metric system (SI). This how-to guide will show you how a. 00 m to 6. For 2,000 LBV soil or greater, two-story buildings may have 12-inch minimum wide footings. Nail one end to the braced form and use the calculated length of the diagonal to set the form at 90 degrees. 4. For this case, the lift should not be. 5 cm) thick footing, the rebar mat is usually placed about 4 inches (10. Detail B: “Wrap and Snap Tie” (diagram upper right) is normally used when tying vertical wall reinforcement to hold the bars securely into. However, there is no need to tie the garage slab to the new foundation, and in fact a strong case against doing so. The second marker expresses the bar size and is demonstrated by a number. Rebar size and spacing is dependent on the strength required. The steel rods help reinforce the strength of the concrete slabs giving the structure a strong form. The architect's instructions on the plan are: “New conc slab with #3 transverse bars at 12” O. Much of your need for reinforcement will be dictated by how well your site was prepared. This new slab design does not account for second floor installations or installations in a ground floor with a basement beneath. ) slabs are plate elements used to form the floors of buildings. Content intended for mature audiences. g. b) Slab depth does not exceed 200 mm when the steel grade is 460. Generally, rebar has an immense impact on concrete. In this article, we will examine the importance of reinforcing concrete with rebar and the proper steps. I'm in the process of designing a elevated composite concrete and metal deck floor slab for a warehouse. My main building is 6" concrete with #4 rebar on a 6X6 grid. These slabs require more load-bearing capacity than other slabs. Also, a small hole in the concrete will be totally fine, given the fact that there is a rebar grid. The design of one-way slab is simple and can be carried out easily. 8 inches. c) Slab reinforcement percentage less than 0. mk . Step 2 - Prepare the Floor. This steel runs vertically and should lap the same size reinforcing steel out of the footing. The design and spacing of expan-sion and control joints is genera l l ysee table 3 for spacing. 7. NOTE: Section 1907. Input the number of mesh in slab rebar. most of the time). Rebar in patios, basement floors, footings and driveways may vary from size 3 to 6. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. 10. If your concrete will be stamped, ask about the best ways to avoid interrupting the pattern. area elements and go to Assign > Shell/Area > Opening to create holes in the slab. Most residential slabs contain. 1 Introduction: A structural member used for covering spaces in the form of roof or floor is called a slab. This is one of the types of concrete slabs. Rebar spacing in a slab footer will depend on the size of the slab, the load it will support, and local codes. Minimum aging of new concrete slab: 28 days (cure time) Minimum width and length of slab: See new slab table & figures below MIN W L R S1 & S2 D I LIFT MODELS SLAB MIN. 5h ≤ 450mm (in areas of concentrated loads 3h ≤ 400mm) Where h is the thickness of. For example, if the first slab is at 12 inches and the second is spaced at 18 inches then measure and place your first mark at 9 inches and then continue spacing the marks at. Spacing (Rebar) A-7 4-1/2” 4000 psi with 28 day aging #6 rebar 12 in. For slabs reinforced with rebar or wire mesh, this is considered fairly routine. If too much water was. Figure 1 shows an example of a floor plan with a composite slab including supple - mental reinforcing bars. Detail B: “Wrap and Snap Tie” (diagram upper right) is normally used when tying vertical wall reinforcement to hold the bars securely into. Our calculator will instantly calculate the quantity of rebar required. ( W) Width of the slab. If the floor is. 73 per square foot for concrete installation. The pri m a r y differe n c e s b e t w een each type are re i n f o rc e m e n t details and joint spacing. Input all the dimensions in the input section of the above calculator. And rebar is sized by eights of an inch. 4 bar at the top and the bottom of the footing or one No. Floor slabs can range from a simple residential basement slab to a heavy-duty industrial floor. 2. 73 Therefore, use 12 mm bars @ 0. In the case of the RCC slab, the maximum spacing between the two parallel main reinforcement bars should be 3D or 300 mm or whatever. a weak concrete has a compression. Generally, #4 rebar (1/2 inch in diameter) is the most common size used for slab on grade applications. European, which is a carbon/steel/manganese alloy. SLAB REINFORCEMENT SIZE REINFORCEMENT SPACING ANCHOR ANCHOR Cutting that rebar ain’t going to do shit, despite all the “engineers” comments to the contrary. 2—Slabs-on-ground 5. , interior beam dimensions = 14 in. No, you do not need rebar for a 4-inch slab of concrete on grade. 4 welded wire reinforcement fabric located in the middle to the upper one-third of the slab. For example, at Column I-4 between the basement and first floor, building plans required four pieces of horizontal rebar through the column in both directions to connect it to the slab. Install tie down 'J' bolts into the slab using a template of the base of the. In the case of the RCC slab, the maximum spacing between the two parallel main reinforcement bars should be 3D or 300 mm or whatever. Vertical rebar every 16 inches. slab opening det. 2. 5 kPa), column spacing typically ranges from 15 to 25 ft (4. With our rebar calculator, you can eliminate. 2130605 2 = second floor B = beam member 06 = 6/8- or 3/4-inch (1. 60 per square foot. 1) provides the code basis. Contractors sometimes use the “1/8 Rule,” meaning the size of the rebar is 1/8 the thickness of the slab. The formula is, Number of bars = (length ÷ spacing) + 1. Crazing is a result of poor surface curing and only visible in hard troweled slabs. By Theodore Neff. Subject: Re: Rebar in shop floor? Kingston,Mi. square poured concrete beams and columns. To se-lect the appropriate steel area (As), use the For example, if both slabs have rebar mats that are spaced at 18 inches and use No. Maximum spacing of bars for slabs • Main bars: 3h ≤ 400mm. MAX and #5 top placed at center of slab" I installed the #3 dowels 12" apart and 6" into the existing surrounding floor. The three different sizes of rebar used for home projects are usually #3, #4, and #5. MotorCity (Structural) 22 May 17 13:44. HOUSE BUILDING IN THE PHILIPPINES - EPISODE 56: REBAR LAYOUT FOR C-JOIST SLAB Message us:Facebook: retir. I have some question regarding the placement of the expansion joints. (as in example diagram) First, enter the concrete slab sizes: length = 6 m, width = 4 m. Reinforcing steel should be properly tied with wire to rigidly support it in its proper. I have 3" x 6" X 16ft treated wood beams @ 3ft on center between. 1 shows the design detail for a secondary containment floor slab with two layers of reinforcing. 5. Theoretically, so long as the horizontal spacing is sufficient, the number of layers shouldn't be much of a problem, but the more layers you have, the greater the odds that the vibrator will accidentally touch the rebar (which it shouldn't). 3: Two-way slabs supported on four sides; Clause 6. Make sure it is in the very center of the slab as if it is too close to the top or bottom it is also useless. If the slab is poured against an existing foundation wall or another slab, you would use the #4 or #5 rebar to dowel it to the which ever you are butting too. The following guidelines given below according to BS 7973-2:2001. It is not hurting anything by putting it in a floor slab, but unless it is in the bottom third of the slab, it is providing zero strength, just keeping the pieces together if it cracks. 2L at the intermediate support. In a typical reinforced concrete building, reinforcement bars arranged as mats are incorporated into a concrete plate of minimum thickness 125 mm to form a reinforced concrete solid slab. Normally, it is assumedchanges in deck slabs, and sloped slabs over beams. UB 610 x 179_BP_Pinned. One Way Slab Bar Bending Schedule Calculation. So, pathway slabs go under heavy loads continuously. In low- to. Exposed rebar will rust, compromising the concrete's strength. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is. The installation of the rebar is critical for the success of the overall project. Some brands of forms have preformed chases that run the length of each. The slab will be 3" thick with 2. 4. 42d. Rebar. Check ACI 360R-10 Guide to design or slabs on ground. Minimum RCC beam size should not be less than 9″x 9″ (225MM X 225MM), with an additional slab thickness of 125 MM. REBAR SPACING: GP‐7 SERIES MODELS: 4‐1/ 4" 3000 PSI / 28 Day Aging #6 Rebar: 12 in: XPR‐9 SERIES MODELS: 4‐1/ 4" 3000 PSI / 28 Day Aging #6 Rebar:. , edge beam dimensions = 14 in. For example in a slab of 6-inch depth, a rebar of 6/8 inch will be used. Parking Structure Fuctional Design Parking Structures:Recommended Practice For Design and Construction Table of Contents 2. L. The suspended reinforced concrete slab is tied into the external capping beam. 6mm. 5% reinforcement (reproduced here as Table 1). , and unfactored live load = 100 psf. 15 1-1 CHAPTER 1 INTRODUCTION 1-1. When concrete is first mixed and poured, it has excess water in it and in the hardening process, the concrete loses its excess water which causes shrinkage cracks. Low-carbon st eel is mostly iron and ferrit e with 0. ACI 302. 78 kg/m 3) in accordance with the manufacturer’s recommendations. The specified compressive strength of concrete shall be as set forth in Section R402. For example, if you’re calculating rebar for a slab, input the slab dimensions, reinforcement spacing, and desired rebar size. If the concrete slab in question is meant to be the footing of a house, then #5 rebar with a. Specify the spacings: rebar-rebar spacing = 40 cm, edge-grid spacing = 8 cm. Ch. It may be desirable to tie and reinforce the new slab to the pre‐existing surrounding floor. It also provides worked examples,. 8 of the Florida Building Code,. PSI means per square inch. 2 – Contraction joints, states the following: “ (d) Joint depth shall be a minimum of ¼ the slab thickness for formed or tooled joints, or dry-cut sawed joints in hardened concrete (e) Joint depth shall be a minimum of 1 in. Here:Bar Tying Requirements. 5. The most commonly used rebar sizes for slabs up to six inches thick are #5 and #4. Measure the cover depth of embedments. Rebar (short for reinforcing bar ), known when massed as reinforcing steel or reinforcement steel, [1] is a steel bar used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and aid the concrete under tension. See full list on everything-about-concrete. Tie the slab rebar into the footing. 5% of the cross sectional area of a slab. a) Slab depth does not exceed 250mm when the steel grade is 250. 00 m 21 reinforced concrete slab 3 mm for every 3. #4 Rebar ; The #4 rebar is often used in residential and commercial projects to add strength in slabs and columns. 50 m span joist, beams, & girder soffit under 3. )(100)/(6 in. Cut a second board to the width of the slab. The spacing of the rebar should increase to between 18 and 24 inches apart for slabs between four and six inches thick. Labor Costs. E. 2ND FLOOR CRACKING WIDTH. Calculation Method For Find Out The Overlapping Length Of Beam, Column And Slab; Bar Bending Schedule For Slab And Estimation Of Steel Reinforcement In Slab; Calculation steps. 6) Calculation of top rebar Please refer to the method in construction site as follows because it is very difficult to explain in theory. For general purpose concrete slabs with 2,500 pounds compression strength, like patios, use a 1:2:4 concrete mix ratio. Industry Practitioners. A flat plate floor with a live load of 100 psf is only about 8% more expensive than one with a live load of 50 psf, primarily due to the minimum thick-ness requirements for. Pool construction crews must place each steel bar and drop of concrete with precision to avoid future structural problems. (a) A flat plate which is a two-way slab supported on a column grid without the use of beams. These cracks have little impact on durability. 376 lbs/ft or 0. Joint spacing normally ranges between 12 to 18 feet depending on the amount of reinforcement the slab has. After placed the (B1) R/F then placed the (B2) R/F and bound both R/F layers together by using binding wire. There should be a minimum of 3 inches of clear cover from the fi nished surface of the slab. a core down to the top of the rebar would confirm its size. So, there exist guidelines for spacing rebar inside a concrete slab. Figure 1a: Joint Spacing in Meters. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright. By Concrete Construction Staff. However, this is the absolute minimum and applies only when there is no load on the concrete slab at all. Matthew Stuart, P. The existing rebar spacing is @ 16 in. ( rS) Rebar Size (2,3,4,5,6,7,8,9,10,11,12,14,16,18,20) Use Size "0" for. 1(a)(5) of ACI 318-19 states that the size limitations on aggregates are provided to facilitate placement of concrete around the reinforcement without. Minimum width and length of slab: See new slab table & figures below. Also, a small hole in the concrete will be totally fine, given the fact that there is a rebar grid. unless otherwise noted, all slabs on grade are to be reinforced with 10mm bars at 400mm o. Advertise Here. Rebar SizesOn studying the drawing, Length of longer side of building = 16. 9 cm)-round bar 05 = part of second floor plan designated by the number 5. The minimum spacing between two reinforcement bars should be at least equal to the maximum coarse aggregate dimension plus a margin of 5 mm. 1. Ilang Araw Ang Pagbuhos Ng Simento? In this video, I'm sharing you the process of concrete pouring and sizes/spacing of rebars for the beams and slab concrete for the. 83-6. A. Concrete reinforcement can be either wire mesh or ½-inch (#4) steel rebar. Average: Rebar in Concrete Slab Estimator. Rebar comes in several types: Steel mesh, made up of steel wires that provide support to the concrete. 20 Plant-applied External Fusion Bond Epoxy Coating [Abrasion-Resistant Overcoat] for Steel Pipe (CSA Group, formerly the Canadian Standards1) Except as provided in Sentences (2) and (3) and in Articles 9. The ACI 318-19 provides a number of requirements regarding slab thickness, concrete cover, and reinforcement ratio which facilitate the design process. 2. It is possible to pour a concrete garage floor without installing rebar for reinforcement. The main reinforcement of the slab panel “A” is marked as (1). 4. Minimum aging of new concrete slab: 28 days (cure time) Minimum thickness of concrete slab: See new slab table & figures below. Kim Min-Koo et al. Generally speaking, a 4-inch slab should include some form of reinforcement such as rebar or wire mesh. In this video, I'm sharing you the process of concrete pouring and sizes/spacing of rebars for the beams and slab concrete for the 2nd floor of this project. 84 m; grid. These slabs are supported directly by the columns and have a completely flat soffit. 3 bars may be used, for constructability and handling reasons it is common practice to use no. ) 400 dowel 400 250 %$56 $6 6+2:1 %277 %$56 # 2 & slab occurs mid-depth of slab [ /21* $7 723 bott. How far apart should rebar be spaced? approximately 12 inches Place rebar in a grid pattern with a spacing between bars of approximately 12 inches. Then use USDA NRCS. A slab with this joint spacing may be reinforced with bars (ASTM A 615, A 616, A 617, or A 706) or WWF (ASTM A 185 or A 497). Top Bars for Slab Continuity Properly designed top reinforcing bars installed above. On average are required, for 10 square meter with 12cm thick slab, 19 strips of 3/8” rods (9ml each one), are 171 ml. or slab change soffit typical detail for beam 400 dowel 250 300 (typ. Sand is filled at a height of 0. Column spacings are 48 feet center to center. Finally, you pour the concrete into the molds. 3% (100As/bd < 0. 64 mm) between longitudinal rebar 2 and 3, which is the same as the rebar construction and traditional tape measurement results. 1. For this case, the lift should not be installed without written authorization from theIt has stood up to some really heavy equipment for 25 years. Multiple layers of c r ossing bars cause these pro b - l e m s . Figure B-10: Alternative Floor Slab Detail. 1: Calculate The Main bars. Step-4: Rebar Calculation Process Of The Slab Panel-A 4. If shear reinforcement is required for in-plane strength, spacing of longitudinal reinforcement shall not exceed l w /5. 3 Slabs-on-ground with turned-down footings. Total Volume of concrete in cubic yards. Generally, rebar spacing in slab footings ranges from 12 to 24 inches, both for horizontal and vertical bars. Thank ForSubscribeLikesShare. Matt, You need to tie the new footing and foundation wall into the existing structure's footing and foundation wall, so yes drill and epoxy the rebar in. 15% for mild steel bars. 🕑 Reading time: 1 minute The design of reinforced concrete (RC) column is carried out by following certain procedures. ACI 318-11. As can be seen from the figure-2 below, the tension reinforcement are 100% at the mid-span of the beam and slab, while it is curtailed at the distance of 0. Unfortunately, rebar can cause extensive damage to construction tools if you are performing coring or concrete cutting work. For beams, these distances are 300 mm, 180 mm and 150 mm for grades of main reinforcement of Fe 250, Fe 415 and Fe 500, respectively. Because our accuracy while scanning with GPR is so high, we. Here, ∅ is the bar diameter. The spacing of such shrinkage-temperature steel cannot exceed 18 in. Calculate how much rebar you need to reinforce a concrete slab. AS3600-2009 P P Lsy. Understanding the Importance of 2nd Floor Slab Thickness for Building Safety and Stability in the Philippines The safety and stability of a building depend on various factors, and one of the most crucial is the thickness of the second-floor slab. of main bars – One = [Lx ÷ bar. The Building Structural Standard defines a two-way slab system as a concrete slab system in which two rebars are arranged in two directions regardless of the presence or absence of a beam that transmits a load to. Then insert 6-foot-long vertical rebars in the cores, properly positioning them in the rebar chairs. If the slab in question is just for a patio or a similar purpose, #3 rebar with a diameter of 3/8-inch will do just fine. 1 of EC2, the recommended minimum spacing of reinforcing bars is 75 mm and 100 mm for laps. For instance, the ACI 318-19 specifies minimum slab thickness that satisfies deflection. and the clear spacing between the bottom bars a = 60 mm. Overlap joints by a minimum of 12” for #3 and 15” for #4, bind with wire ties, and keep the steel 3” back from the. (150 to 250 mm). Step 1.