Place rebar in a grid pattern with a spacing between bars of approximately 12 inches. However, if the slab is subject to heavy load or if it’s used as a structural support, you may need to go larger, such as #6 (3/4-inch diameter) or even #7 (7/8-inch diameter). No, you do not need rebar for a 4-inch slab of concrete on grade. Concrete slabs-on-ground shall contain micro- or macro-synthetic fiber reinforcement. An 8-inch slab or thicker is required for CJ’s spaced up to 20 feet. Wood sole plates at all exterior walls on monolithic slabs, wood sole plates of braced wall panels at building interiors on monolithic slabs and all wood sill plates shall be anchored to the foundation with minimum 1 / 2-inch-diameter (12. 4/1. Wood sole plates at all exterior walls on monolithic slabs, wood sole plates of braced wall panels at building interiors on monolithic slabs and all wood sill plates shall be anchored to the foundation with minimum 1 / 2-inch-diameter (12. It has a foot print of four tires about 10 inches by 10 inches time 4. The splices should have at least 2 ft overlap into the new pour. I'd go #4 rebar at 18-inch max spacing. 2-inch midspan c a m b e r, the beam delive r ed to the jobsite might have a 13⁄ 4-inch cam-b e r. 78. Position and placement of RebarsMin reinforcement is 0. 3. Similarly, rebar with a size 15 will be 15/8. 375 inches, which is equivalent to 9. Rebar Spacing. For slab thicknesses 12 inches or less, the concrete cover tolerance is - 3/8 inch. 45 cubic feet. Step-4: Rebar Calculation Process Of The Slab Panel-A 4. In inches the diameter of a #5 rebar is 5/8″ and that of a #4 rebar is 1/2″. 11 in. 4 m) 6 inches (15. To get the rebar in the bottom 1/3rd of the slab, a 1" chair would been perfect for a 4" slab, a 2" would be good for a 6" Slab, and a 3" for something crazy thick like 8"+. Have a helper add or remove concrete in. diameter. A 4 – inch -thick slab cast on the ground and in permanent contact with it will float and rebar is not required. Here:The size of rebar needed for a 4-inch slab depends on several factors, such as the type of material used for the slab, the type of project, and the size and weight of the load it will be required to carry. The length of the lap varies depend on concrete strength, the rebar grade, size, and spacing. The Rebar calculator for slab is best to find the Rebar size. First, find the area of the slab. 5% reinforcing steel in the top 2 inches of the slab in both directions can allow you to eliminate joints. The gauge, or diameter, of the rebar is selected based on the purpose and the load-bearing requirements of the structure: For standard residential concrete slabs, #3 (3/8 inch diameter) to #5 (5/8 inch diameter) rebar is typically used. 60 per square foot for materials and labor. 5 inches of spacing (18" + 1/2" diameter of the rebar). The national average cost of a concrete slab is $6. For driveways and patios, #4 (1/2 inch diameter) rebar is a common choice. Its rebar size in inches is 0. Pour footings and wall. 74 sq feet 5000/2. Generally, rebar is Grade 32 and utilized for 3-inch slabs. 7 mm) anchor bolts spaced not greater than 6 feet (1829 mm) on center or approved anchors or anchor straps. Generally speaking, when pouring a 6 inch slab, #4 or #5 rebar is used. area = 25′ × 25′. #4 Rebar ; The #4 rebar is often used in residential and commercial projects to add strength in slabs and columns. Space the joints no more than 2-3 times (in feet) of the slab’s thickness (in inches). 45 to 1. It is not necessary to use rebar for a 4 inch slab, as concrete’s compression strength alone is enough to hold a 4 inch slab in most cases. 8" - 3/4" (top cover) - 2" (4-#4 bars) - 3" (bottom. The compacted aggregate base is first, followed by a 6 mil polyethylene vapor barrier, then insulation, then rebar or wire mesh, or both. The ribs aren’t included in the measurement and the diameter is expressed in eighths of an inch. For example, a size 4 rebar will have a diameter of 4/8” or ½ inches. Sub-slab details (i. Drive 12-in. Talk to your local building inspector or hot tub retailer for more specific guidance on slab thickness for your situation. Step 4: To determine the number of crossing bars you will need, divide the length of the driveway by the rebar grid spacing. approximately the bar diameter in eighths of an inch [whole millimeters], used to designate the reinforcing bar size. 1 Type A - The dowel structure shall comprise a single metallic material meeting the requirements of AASHTO M 255M/M 255, AASHTO M 334, ASTM A276, ASTM A312, or ASTM A1035 (CS, CM and CL). This means 2x 3/8 inch rebar makes 3/4 inch of steel. Add one more length to allow for that extra, giving you a total of 18. 5. transverse wire spacing with smooth No. For example, a slab that is 6 inches thick might have rebar marked as size 6 or 3/4-inch. Never put a shop on a slab less than 6" thick. Slabs, walls, and joists: #11 bars and smaller: ¾ inch. #6 bars and larger – 2 inches #5 bars or smaller – 1½ inches. Beams and columns: 1½ inches. Contractors sometimes use the “1/8 Rule,” meaning the size of the rebar is 1/8 the thickness of the slab. There are three different sizes of rebar typically used for home construction projects. I like to use a #3 (3/8 inch) piece of deformed rebar, 18 inches long. aggregate, you'd need 1. Rebar spacing in a slab footer will depend on the size of the slab, the load it will support, and local codes. For larger slabs, cut control joints into the surface to accommodate shrinkage and changes in temperature. 08 x 50 = 4 total cubic yards of concrete for 50 tubes4. For a standard 6-inch thick concrete slab, you will need between 6 and 7 pounds of rebar per square foot. The ACI 318-19 provides a number of requirements regarding slab thickness, concrete cover, and reinforcement ratio which facilitate the design process. The important part is the use of support to achieve proper placement within the slab. A 4-inch concrete slab with a 2-inch road base and #3 rebar at 16-inch spacing can provide a reasonably strong foundation for a patio structure such as a patio cover or gazebo. 4m2. If the wall exceeds four feet in height, footings should be poured. Before beginning a concrete project, consult a professional engineer to determine the code requirements and what size and spacing of rebar will best meet. 33 inches. Concrete volume calculator plan view diagram. Rebar spacing in a slab footer will depend on the size of the slab, the load it will support, and local codes. For thin slabs, such as those less than 4 inches thick, the most common size of rebar used is 5/8 inch. 5x the maximum aggregate size. 6 for the recommended CJ spacing for unreinforced concrete slabs-on-ground as follows: Note that CJ spacing in a 4-inch slab should be between 8 feet and 13 feet. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright. 5 range tops, and control joints are formed either with preformed joint material or sawcut within the first 24 hours and be sure that the curing conditions are good, at least 50 F. To reinforce a 4” concrete slab or driveway with steel rebar, determine the grid spacing and rebar size – #3 or #4 in a 12” to 18” grid. 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). 376 lbs/ft or 0. 17 inches (18" controls) #3 bar = 10. Fiber and welded wire are only used for shrinks cracks, non structure cracks, cosmetic cracks. 75-in x 1. 4/1. Reading time: 4 minutes. Reinforcing concrete slabs with rebar is an excellent way to prevent slab failure, as long as the slab is not over 4 inches thick. If you have a 5 inch slab and multiply it by 24 to 32 you will find that your joints should be placed every 120 to 180 inches or 10 to 15 feet; Or another way to figure this out is to times it by 2 or 3 in feet. Drag a straight 2×4 (screed board) across the top of the concrete forms to level the concrete. Workmanship and jobsite conditions. thick slab, the maximum joint spacing should be. Using rebar in a 4-inch slab provides a multitude of benefits, enhancing the structure’s strength, stability, and durability. For flat slabs like driveways, a grid spacing of 18 inches is recommended, with the edge rebar placed at the same distance from each side. 8 mm) ±1/2 inch (±12. As per the present market rates, the average cost of concrete for a 400-square foot slab, the typical size for a two-car garage, ranges between $583 and $637 or between $1. For ½“ rebar the inside of the bend should have a diameter of at least 3 inches. If the concrete thickness is greater than 8 inches, the spacing of the rebar may be increased in order to prevent lateral buckling of the rebar. CRSI’s Reinforcement Anchorage and Splices includes tables of required lap splice lengths based on these variables. We followed all of those and 2 years later we're glad we did!1. Contact splices. The #3 rebar has a weight per length of 0. See STRIPS. If your footings are 16 inches wide, you will need to add two sticks of rebar along the width of the footing; however, if your footings are 24 inches wide, you will need three sticks. Rebar in patios, basement floors, footings and driveways may vary from size 3 to 6. Generally, one stick of rebar per 8 inches of footing width will suffice. Above 12 1/4” they have a single cover height per chair. Some, even, go so far as to recommend NO reinforcing, allowing the deck to actually arch across the span to the supporting girders. This is done by inserting #4 rebar dowels a minimum of 6 inches into the center of the footing’s wet concrete, spaced typically at 4 feet on center. Main reinforcement which is based on the maximum bending moment shall not be less than 0. They're compatible with rebar sizes #3 to #5 and can elevate your rebar either 1 1/2 inch or 2 inches off the ground. 7. Common practice is to place supports 2 to 3 feet apart. 4 x Modulus of Rupture fs = allowable working stress of the reinforcement (psi) T =range of temperature the slab is expected to be subjected to (F o)Stretch a string between two screws installed at the edge of both ends of the form boards. 33 inches. Step 1: – Calculate numbers of distribution rods. The details of slab reinforcement are given below. New concrete slabs must conform to the above. This translates to roughly 5/8 inch rebar and must be spaced equally along the slab to create a proper grid. Rebar is used t o help improve concrete’s resistance to loads andThe maximum diameter of bar used in slab should not exceed 1/8 of the total thickness of slab. ) In metric the bar size is approximately its diameter in millimeters: a 25 bar is 25. And the rebar. 1. 1% reinforcement in a 4-inch thick slab is #3 bars in both directions at 24-inches. Leave a few inches of space between the mesh and the edges of the forms to prevent rust. Furthermore, if the concrete. 668 pounds; Applications: Residential foundations, thin concrete structures, and masonry walls. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is. I will drill with a hammer drill and a 3/8 bit through the expansion material and into the existing slab about 6 inches. Here’s a complete chart of different rebar sizes, their diameters, and weight: Rebar markings. For example: A #5 [#16] bar is approximately 5/8 inch [16 millimeters] in diameter: a #9 [#29] bar is approximately 9/8 inches [29. Generally speaking, a 4-inch slab of normal weight concrete (145-165 pounds per cubic foot) with a 28-day compressive strength of at least. 24-foot joint spacing. If you prefer to calculate the number of bags of concrete needed, you can use the weight of the bags as a reference. Conclusion. Generally speaking, a. Slabs, walls/dividers, and joists – 11 bars and littler – ¾ inch. Where: As = cross-sectional area in square inches of steel per lineal foot of slab width t= thickness of slab in inches fr = tensile strength of concrete (psi) = 0. A few rules of thumb for control joints: Space them 2 to 3 times in feet the thickness of the slab in inches (4" slab = 8' to 12' max); Joints should create nearly square sections; joints should be struck or sawn to a depth of 1/4 the slab thickness; Sawn joints need to be cut before shrinkage cracks occur, no more than 12 hours. 33_6_0. The spacing will depend upon the wire size and the wire spacing. For slabs and pads, the distance between rebar is normally 4-6 inches apart. Suppose you have a concrete slab with dimensions 10 feet by 8 feet by 6 inches, and you plan to use #4 rebars with a spacing of 12 inches. You can't get that in a four inch slab. Rule of thumb is to have the minimum clear spacing between bars be 1. 9_sqrt (Pt), with P representing the percentage of steel required and t representing the thickness of the slab. Rebar Spacing. Use 2” rebar chairs to support the rebar in the center strata of the pad. Suggested applications - concrete slabs, precast, tilt-up, bridge deck, and other heavy applications. If the slab is expected to bear heavier loads, such as from. Positioning a single layer of reinforcement in the center or at mid-depth of the slab is not recommended (except for 4-inch-thick slabs). That's 144 square inches. Generally speaking, it’s recommended to use #5 rebar if the slab is 4 to 6 inches thick and is being used for residential construction. INSTRUCTIONS: Choose units and enter the following: ( L) Length of the slab. 5 to determine you will need 120 feet of rebar. 7 mm) anchor bolts spaced a maximum of 6 feet (1829 mm) on center or approved anchors or anchor straps. For slab thicknesses 12 inches or less, the concrete cover tolerance is - 3/8 inch. 73 per square foot for concrete installation. If the concrete thickness is greater than 8 inches, the spacing of the rebar may be increased in order to prevent lateral buckling of the rebar. The top surface needs to remain wet while the curing process takes place. A little more cash now is worth no cracks later but I always overkill. For M15 concrete, lever arm = 0. Acorn International 2. Joint distance (D) or tank diameter in feet based on Steel Schedule Minimum end area (As) of steel (in2) for slab thickness, t= 5 inch * Anchor bolts are located a minimum of 1 3 / 4 inches (45 mm) from the edge of the concrete parallel to the length of the wood sill plate. Use a metal-cutting blade or disc in a reciprocating saw, circular saw or grinder to cut the rebar. However, if the slab is subject to heavy load or if it’s used as a structural support, you may need to go larger, such as #6 (3/4-inch diameter) or even #7 (7/8-inch diameter). Convert the weight of the bag to the volume. 440 3. No, you do not need rebar for a 4-inch slab of concrete on grade. 5. Prices for your concrete slab will vary significantly depending on many factors, including the slab’s thickness, concrete type, and size. 5 inch line of your patio slab to keep the dowels in the upper portion of the slab. For flat slabs, grid spacing of 18 inches for driveways and 24 inches for patios is recommended. #5 bars are 5/8”. If you have a 5 inch slab and multiply it by 24 to 32 you will find that your joints should be placed every 120 to 180 inches or 10 to 15 feet; Or another way to figure this out is to times it by 2 or 3 in feet. The cover required is 2 inches for foundation walls, or walls exposed to. 1. The reinforcing steel sagged during placement between the support chairs, causing the 3/4-inch spacing to be infringed upon. 5-inch cover to the beam stirrups, dagg = 3⁄4 inch, #3 stirrups used with #4, #5, and #6 longitudinal bars, and #4 stirrups used for #7 and larger longitudinal bars. 34 and $7. a car weight about 5000lb. spacings: #4 bar = 18. 525 mm. In general, you’ll want a slab that is at least 4 inches thick, but 6-8 inches is even better. The tools you need to build a concrete slab. Rebar should be placed evenly throughout the project. 60 per square foot for materials and labor. I used no. View More. The reason is because the lower part of the slab (from the center of the thickness down) is in tension when the load is on the top of the slab. Dosage amounts shall be from 0. In that case, a layer of rebar near the bottom or at. October 9, 2021. 65 and the thickness of the slab is 6 inches, M = 0. I was thinking of going with the same spacing. They cannot hold a load factor. For example, a size 3 rod has a diameter of 3/8-inch. e. 59 per square foot. PROWORX 3-in x 60-in x 3-in Steel Slab Bolster. Tractor. That means placing the wire on chairs to hold it at the correct height (see below). For a patio you can use a grid spacing of 24 inches. 5. 4 wire mesh in a 4-inch slab, P = 8. By understanding these basic. The spacing and quantity of the rebar will depend on factors such as the load the slab needs to support and local building codes. The concrete contractors said that these rebar chairs were a great idea, but the execution and labeling of the product was very poorly thought out. The 2021 IRC® contains many important changes such as: Braced wall lines must be placed on a physical wall or placed between multiple walls. For a 4-inch slab, #3 rebar should be spaced 12 inches apart on center. Rebar should be placed evenly throughout the project. All thick slabs can be categorized into:. For garage slabs, two rows of #4 rebar are recommended around the perimeter, one above the other. Here: Multiply the measurements together to calculate the square footage of the area. d. Video of the Day Step 2: Dig Out the Area Excavate the concrete pad area 6 inches deep to prepare the ground for the concrete. 5 mm) for concrete slab depth ≤12 inch (304. Control joints can be added to your concrete slab extension in two ways: Create a control joint when the concrete is still wet using a grooving toolRebar is best used in a driveway for which 5-6 inches of concrete can be poured. Do you need rebar for 4 inch slab? No, you do not need rebar for a 4 – inch slab of concrete on grade. It's not a problem to get two layers in on an interior 8" elevated slab where the bottom cover is 3/4". The string will act as a guide to keep the form boards straight. If the floor is designed as a reinforced-concrete slab requiring rebar in the tension zone, the designer should specify the correct rebar position. 33_2_0. 058 percent, which is only enough for crack containment. Concrete subject to moderate or severe weathering as indicated in Table R301. Proper installation that provides maximum strength requires the mesh to be raised off the ground so that when the concrete sets, it’s in the lower third of the slab depth. Tractor. Most DOT's use double layers in their decks. apart. All 3/4 inch diameter anchors must be a minimum of 6 inches away from any expansion seams, control joints or other inconsistencies in the concrete. Divide your result by the spacing measurement: 180 / 14 = 12. rebar strength is in tension, so by adding rebar to BOTTOM of foundation, it counter acts the load of compression. This video series w. Advertise Here. The grade shall be as specified by the. 16 inches for a number three bar. We would like to show you a description here but the site won’t allow us. For columns and beams, the minimum spacing should be 6 inches. For a 4-inch RCC (Reinforced Concrete) slab, using #3 (3/8-inch diameter) or #4 (1/2-inch diameter) rebar is typical. A 6" slab is quite minimal for most bridge deck applications. They are 4 feet in height and 10 inches in width (diameter), or 4' x 10". Say your forklift has a contact area of 1 square foot. Main bar is also called as shortest span bar usually used at bottom of slab having spacing 4 inch between the two bar. to 8 in. of Main bars = (Width of Slab/Spacing) + 1. You can multiply the bar size by 1/8 to get the nominal diameter in inches. User note: About this chapter: Chapter 4 provides requirements for constructing footings and walls for foundations of wood, masonry, concrete and precast concrete. 5% of the slab cross-sectional area. _____ Bar Supports Bar supports are required in a number of locations on bridges. Ask Your Own Structural Engineering Question. This type of rebar is typically 6mm in diameter and can span up to 24. Having installed thousands of slab on grade foundations over some 26 years as an ironworker, I can say that if it was my driveway, I would probably do 5 inch thick concrete with #4 rebar at 18 to 24 inches each way at center of slab in other words 2" chairs or dobies at every intersection and deepened perimeter footings. #3 is most commonly used for patios and driveways, #4 for columns and walls, and #5 for foundations and footers. 65*6) = 1. Again, without mesh this drops to 34,300 lbs. 7 mm) anchor bolts spaced a maximum of 6 feet (1829 mm) on center or approved anchors or anchor straps. Step 5 – Place the Mesh. 7. The spacing of the rebar is typically 12” on center for most residential applications. area = 625. The thickness of rebar should be no more than 1/8 that of the slab, so a 4” slab shouldn’t have steel greater than #4 or 1/2″ bar. Do You Need Rebar For A 4 Inch Driveway Slab? A 4 inch concrete driveway slab is too thin for rebar. Common practice is to place supports 2 to 3 feet apart. 1. In slabs with an average thickness of less than 6 inches, the spacing should be at. For example, let’s find the number of 5′ x 50′ rolls of mesh required to reinforce a slab that is 25′ by 25′. (iii) three-fourths the minimum specified clear spacing between individual reinforcing bars or wires. Regardless of beam spacing, the top mat must be tied to the forms or the bottom reinforcing mat at 4 foot spacing. All 3/4 inch diameter anchors must be a minimum of 6 inches away from any expansion seams, control joints or other inconsistencies in the concrete. The exact size rebar you will need for a 4 inch slab will depend on several factors, including the application, the load being carried, and any seismic or other environmental considerations. 9 3 in. Read more on low-shrinkage concrete mixes in the Concrete Mix Design section. For a 400 square foot slab, the man hours required to finish a two-car concrete garage slab is about 13 hours. For a 4-inch slab, #3 rebar should be spaced 12 inches apart on center. For example, if both slabs have rebar mats that are spaced at 18 inches and use No. Calculates approximate Rebar Length from total slab area and perimeter. Additionally, it plays a crucial role in preventing cracking and shrinkage, ensuring long-term reliability. For beams and walls, the spacing should be closer and is usually 3-4 inches apart. 4 inch Joist Spacing SLAB MESH THICKNESS SIZE 3 in. Calculate Rebar Spacing, Layout and Weight in a Concrete Slab To calculate Concrete and Total Rebar in a multi sided slab see: Calculate Concrete and Rebar in Multi Sided Slabs 16 Bars @ 11'- 6" 10 Bars @ 19'- 6" Total Length 420 ft Includes 10% waste / lap Exact Spacing Length 16" mid 10" Width 16" mid 10" 21 x 20 ft Lengths $ (Enter Cost per Bar) See full list on everything-about-concrete. This doesn't really eliminate cracks, but results in very. Guidance for joint spacing to minimize out-of-joint. You can use regular fencing material with 2' x 4' or 2' x 6' mesh. Put the mesh on wire supports, sold separately, so it sits roughly in the middle of the slab’s thickness. 10. 1. Then, the new slab needs to be left alone. 12% for HYSD bars and 0. Typically, for residential construction, you might use #4 (1/2 inch) or #5 (5/8 inch) rebar spaced at 12 inches on center for a 4-inch thick slab and closer spacing for a 5-inch thick slab. Ridges in the surface of the rebar allow the concrete to adhere to it and create one solid structure. The #3 rebar has a weight per length of 0. For a flat slab, such as a driveway, consider placing the rebar in an 18 inch grid spacing, keeping the edge rebar at the same distance from each side. Available Heights: 3” to 12-1/4” in 1/4” increments. For a. (Rebar Calculation Formula) No. 8 wire transversely). Anchors are embedded into concrete a minimum of 7 inches (178 mm). For the slab's longer dimension, you'll need 360 inches divided by 14, which gives you 25 plus a bit left over. This spacing will provide the maximum reinforcement of the. but dig the edges deeper like a footer and use normal rebar spacing for the footer. In order to calculate this, you need to input the length and width. Most residential slabs contain reinforcement of less than 0. 34 inch (8. Methods used for finding slab thickness varies for different types of slabs. Moreover, chloride ions from marine salt. Stocked in half inch increments between 6. However, there is no need to tie the garage slab to the new foundation, and in fact a strong case against doing so. 2-inch midspan c a m b e r, the beam delive r ed to the jobsite might have a 13⁄ 4-inch cam-b e r. Horizontal rebar is. Rebar size is first number - 4,5 or 6, second number, in inches, is vertical on center spacing 2. Per ACI 332. For exam-ple, for a one-way solid slab, with #5 temperature-shrinkage bars, high chairs are used at 4 feet on center; for #4 bars, high chairs would be placed 3 feet on center to prevent sagging. For the short side, 240 inches divided by 14 inches gives you 17 lengths of 20-foot rebar plus a bit left over. Table 1-Minimum Shrinkage and Temperature Reinforcement steel for non-SES floors or SES floors with a secondary liner. This thicker rebar will improve the durability of a 4-inch slab and therefore its lifetime. B3030. 7 mm). If you’re making a slab 4 inches tall, use Grade 40 or Grade 50 rebar. Acorn International 2. Use 2” rebar chairs to support the rebar in the center strata of the pad. To calculate Total Area of a multi sided slab, first divide the shape into rectangles or squares. but what spacing do I use between the turned rebar and how far down the 18" turndown. construction projects. Joint distance (D) or tank diameter in feet based on Steel Schedule Minimum end area (As) of steel (in2) for slab thickness, t= 5 inch *1. The spacing of the rebar should increase to between 18 and 24 inches apart for slabs between four and six inches thick. Finally, take a look at the calculation results: grid length = 5. For most residential slabs, such as patio slabs and sidewalks, #4 rebar (1/2-inch diameter) spaced 12 inches apart is recommended. How do you calculate rebar for a slab? Layout of Rebar for Concrete Slabs. Wilkerson, PE. The percentage of reinforcing refers to the cross-sectional area of the steel for a given width of slab divided by the cross-sectional area of the slab area considered. Down here in gator country my architect would typically prescribe: drill and epoxy 36" #5s 24" o. 10%. 26 inches (18" controls) #3 bar = 15. Rebar is short form of reinforcing bar, it is steel bar or Steel wire provided as tension bar, used in. For concrete not presented to climate or in contact with the ground: chunks, dividers, and joists – #14 and #18 bars – ½ inch. Q: Can rebar rust in concrete? A: Rebar can rust in concrete if it is exposed due to cracking or delamination. Wood sole plates at all exterior walls on monolithic slabs, wood sole plates of braced wall panels at building interiors on monolithic slabs and all wood sill plates shall be anchored to the foundation with minimum 1 / 2-inch-diameter (12. . Rebar is typically calculated at a rate of 1 for every 8 inches of footing width. Anchorage shall be in accordance with Section R403. In conjunction with the bar callouts in Figure 1, minimum extensions for the top and bottom reinforcing bars in the column and middle strips must be provided. 5. 12. 46 and $1. 9. The evaluation of rebar spacing results shows that the maximum standard deviation for rebar spacing is 0. 5 rebar, then measure and mark for your dowels at a 18. PROWORX 3-in x 60-in x 3-in Steel Slab Bolster. 2. Generally I would go with the #4 rebar (1/2-inch diameter) since the difference is cost should be negligible and it provides better construction (there should not be any splices in the rebar on a slab this small). Joint spacing in the topping should be coordinated with joint spacing in the base slab.