Rebar into existing foundation. Dec 1, 1997 · Q.

Rebar into existing foundation. Mar 7, 2016 · Every once in a while I get to learn something new and share one of those tips with you. After blowing the holes clean, we injected SET 22 High-Strength Epoxy-Tie adhesive (800/999-5099, simpsonanchors. I would not recommend this approach, and always work to retain original bars where possible. Delve into the benefits of traditional steel, fiberglass, and composite rebar options, ensuring your project Reinforcing bars installed into hardened concrete using an adhesive product are called “post-installed” reinforcing bars. Perfect for DIY I would definitely recommend pinning the new slab into the existing foundation. Jun 17, 2020 · I've done some internet searches, and it seems to be a 75%-25% split with most people saying not to tie the rebar into the house, with the idea that when the new slab settles, it will add tension to the existing foundation wall and possibly cause cracks and problems down the road. I have looked for a similar post on several Mar 10, 2019 · The most common modification that we encountered during site construction is the addition of structural members to the existing one. I was thinkin about connecting it with rebar (in the middle of the thickness of existing slab). Alternating full-length re-bar for doweling into existing concmore Dowels are critical for tying an existing foundation to a new one. Discover the importance of rebar in concrete footings, its installation, sizing, and placement for a strong and stable foundation. I drilled 1/2" into it (3" deep) and got 1/2" rebar but it fits loosely. Apr 22, 2023 · In general, Drill &! dowel into existing and lap rein to dowels if you intend to rein the new foundation / slab. Carry the dowels either one development length, or in your case, the full height of the wall. Jan 15, 2005 · Does anyone have suggestions on details relating to tying a new foundation into an existing concrete foundation to optimize structural and watertight integrity? We are considering the typical rebar pin in epoxy filled hole and are looking for tried and true ideas to block water infiltration. Jan 18, 2010 · When joining new concrete work to old concrete work, the joint will always develop a crack and will be a point of expansion and contraction. Add 3/4 crush rock and tamp it to take some volume out . I asked one company if the new patio would tied into existing foundation with dowels or rebar etc. These are commonly referred to as post-installed reinforcing bars. Jul 13, 2019 · Has anyone thought about using steel rebar on the inside of a concrete basement block wall to reinforce it and prevent further bowing and cracking? What I am suggesting is cutting vertical v-shaped grooves in the inside face of the block wall, floor to ceiling at regular intervals maybe every 2 Jan 13, 2010 · Existing house with 48" crawlspace, 8" CMU on 8h x 16w continuous footing, will get an addition. Better would be to create an interface zone where you chip to expose existing bars and lap these with new, casting both into a joint zone. Here’s a step-by-step guide on how to do Dec 6, 2024 · This process involves preparing the existing concrete, digging a new footing area, adding rebar, and pouring new concrete. Attached an image of it, there is no bearing Dec 1, 1992 · Q. how does the code fit in the picture here? ence of existing reinforcing must be taken into account. Drill holes into the existing slab edge and insert smooth steel dowels coated with bond breaker or grease to allow horizontal movement but prevent vertical displacement. A crew member started by drilling holes at the top of the adjacent foundation walls. For this, the proper and step by step procedure should be followed by the engineers in order to attain a safe and sound execution. Rebar should be placed at intervals of 4 to 6 feet along the length of the wall as well as on each end, with one end of the rebar inserted The patio is going to settle on the free end, meaning that it will not be remotely level as the end doweled into the existing foundation is not going to move. Learn essential techniques to prevent structural issues and ensure a durable, long-lasting result. 6 inch doesn’t do any harm. A couple thoughts came to Sure when we’re doing commercial construction we’ll dowel sidewalks into the foundation below doorways, but that sub grade has been compacted, tested, and we poured the concrete and know what the rebar is like in the foundation walls. Jul 17, 2025 · When working on a foundation strengthening, modification, or retrofit, one needs to realize that attaching rebar vertically to an existing concrete beam is a task of precision and experience. Aug 29, 2011 · The most common way of doing this is to drill into the supporting structure, and install deformed rebar dowels using adhesive. Jan 3, 2024 · SCOPE This IR applies to the design of new foundation elements, including both shallow and deep foundation systems. At the concrete interface I am planning on drilling and epoxying rebar into the existing concrete and extending it into the new concrete and provide a class “B” lap length. For renovation projects, this helps facilitate the expansion of floor space or address other function changes in a structure. These include controlling surface water and subsurface drainage E) and reinforcing steel detailer in showing reinforcing steel details. Nothing fancy, it's just a regular 4 inches thick 3/8 rebar, 3000PSI concrete Jun 22, 2025 · Connecting a new concrete slab to an existing one is a straightforward process that can be done by drilling horizontal holes in both slabs and epoxying rebar into them. Im wondering about modeling supports for a new slab at the edge of the slab Dec 1, 2008 · Doweling the Slab Edges To create a stable cold joint, we doweled the new slab into the old one. Jul 29, 2003 · I’m about to build a small (4′ by 6′) addition. Discover tips on spacing, common mistakes to avoid, and how rebar can significantly increase the lifespan of your concrete structures. In this area, some munici-palities allow a new home built as part of a teardown to be permitted as a remodel rather than as new construction, provided it’s built on the existing I've seen engineer videos explaining the concept, but no videos of the actual process. Also as far as the rebar goes, the spacing looks good but I would probably put two layers instead of one or if I used one I Learn how to stabilize a crack in a concrete basement foundation wall and prevent further damage using wood and epoxy. In any means, the only way to connect an additional structure from an existing is though drill and fix method. Simply demolishing the garage and starting from scratch would have made more sense but wasn’t an option: Since the garage sidewall was in Learn how to reinforce concrete with rebar to enhance strength and durability in your projects. rebar pounded into holes drilled in the existing footing. Learn how rebar enhances the strength and durability of slabs, prevents cracking, and extends lifespan. Evaluating and Reusing Existing Foundations: Insights from Matt Risinger and Jake Bruton In this episode, builders Matt Risinger and Jake Bruton delve into the considerations and best practices when reusing an existing foundation for new construction or remodeling projects. Sep 18, 2025 · Install rebar dowels: To ensure a strong bond between the old and new concrete, rebar dowels should be installed into the existing slab. Then the crew used high-strength epoxy to attach two lengths of rebar at one end of the wall. Common methods include adding steel reinforcement bars (or rebar) into existing concrete foundations or installing helical piers which anchor the house’s foundation into the ground. This steel gets the name “reinforcing” when used in conjunction with concrete to reduce cracking and movement. The number and type of bars will depend on the load of the new structure. Discover essential preparation tips, necessary tools, and step-by-step instructions that simplify the process. What do you recommend for the structural tie of new walls to existing, where they tee into them? I thought of a couple. No. Mar 9, 2021 · One of the things I’m struggling with is how to tie the addition’s foundation into the existing foundation. The most important part is drilling into the old concrete and attaching some reinforcing bars, the second part is to prep the old concrete by painting on a cement and water mix. 4 rebar, 1/2” (13 mm) in diameter, is the minimum size recommended for use with epoxy grout. The best way to tie in a new slab is to drill into the edge of the existing slab at least four inches, and grout in short lengths of rebar, which will extend into the new slab. Brent Anderson responds: There are many ways to support a garage slab next to a basement wall. Foundation layout is set in concrete. Holes go in existing slab. I'm pouring concrete and to tie it to the old floor I've opted for rebar. The installation consists of drilling a hole into a concrete member, injecting adhesive into the hole, and inserting the reinforcing bar into the hole so that the adhesive, when cured, will bond to the concrete and the bar. These dowels should be spaced about 12 inches apart and should extend about 6 inches into the existing slab. May 4, 2023 · Do the plans call for rebar in the footings and wall? Most of the time what ever rebar we are installing is drilled into the old concrete as laid out by the engineer or discussed with the inspector, who ever will be inspecting the forms before you pour concrete. The contractor would have to side drill into the foundation and epoxy in rebar stubs or something. What’s the best way to support a new garage slab next to an existing foundation wall? A. Feb 21, 2007 · I have been asked by a client to design a foundation for a building which will cover an existing structure (a concrete aggregate bin). It is divided into three parts: one addressed to the A/E, on for the detailer, and a third providing a reference table an Reinforcing Bar Installation in Epoxy Grouts The use of reinforcement bars is recommended in deep pours to minimize cracking and help transfer stress if cracks do occur. Assume that load transfer between new and existing rebar is required. 1 day ago · Learn how to successfully join a new concrete slab to an existing one with our comprehensive guide. or perhaps no epoxy and just form oil/grease 4) How deep should the hole in the existing concrete be and how much should the rebar stick out. It might sound complex, but following the right steps ensures a strong and stable foundation for years to come. Discover best practices for spacing and tying rebar to Nov 3, 2014 · I wouldn't dowel in, there's too much risk of cracking the existing slab and it really won't help stabilize the new slab. I'm wondering if I should somehow tie the new walls I'm going to put in to the existing poured foundation. The carport has very good foundations all around, and I'd like to reenforce my concrete slab by tying the rebar into the existing foundation. I would love your insights and advice. Based on a conversation with the inspector, I will put two rebar in both the footing and the stemwall. Use epoxy to set rebar stubs into the existing slab, and tie them to the rebar grid of the new slab. However, there is no need to tie the garage slab to the new foundation, and in fact a strong case against doing so. This is often a need for new construction with a preferred construction sequence. . You are trying for it not to move. What is the best way to tie a new block addition into an existing block building? A. Another consideration is whether or not you have to put a grounding bond on the rebar underneath Feb 9, 2017 · A CFA member asks for an interpretation of the cover requirements for dowels in a footing used to provide connection between the concrete footing and the foundation wall. I found some articles on Fine Homebuilding about drilling holes into the existing foundation and putting rebar into them. It is common in restoring old buildings, “pop-top” renovations (adding stories to a property), and condo conversion (subdividing a property into multiple units Jun 26, 2025 · There are several ways to extend a concrete slab to an existing slab. Dec 1, 1997 · Q. In addition to the issues of settlement and frost-heave as noted above, there is also the issue of the connecting rebar rusting and that rust traveling into both slabs and the foundation wall. This article provides a comprehensive overview of rebar's crucial role, types, and selection criteria, along with step-by-step guidance for installation. This article covers everything you need to know about adding a footing to an existing concrete slab. Aug 29, 2023 · Post-installed rebar development design In this article, we have addressed the important and challenging issue of designing and developing the length of concrete structure rebars after the … Feb 9, 2014 · Is the existing foundation block? If it is you can line up the new wall with the cells and tooth them together by knocking out some of the old foundation block. In addition to a foundation's ability to support the required design loads, this chapter addresses several other factors that can affect foundation performance. We cover key techniques, including mechanical and chemical methods, and emphasize the importance of proper curing and mixing. Apr 29, 2013 · The problem you are going to encounter is that the existing rebar and your new rebar will be creating a plane of weakness in your existing concrete. Basically, I am planning to increase the height of a 3. Jan 6, 2016 · 2) Should I drill the holes just 1/8" larger than the rebar? 3) What type of epoxy (or whatever) should be used to hold the rebar? . Sep 18, 2025 · Learn how to reinforce concrete with rebar. If it helps at all, I live in KS and the soil is a dense clay. The most commonly used method for reinforcing concrete block walls is to use metal rebar, or steel rods, to reinforce the integrity of the blocks. This, obviously Oct 27, 2016 · Hi All, Its been a while since I posted here so I am glad to be back, My topic is this, do you guys who do block foundations have any reservations about drilling into concrete footings? We just completed a block job that called for the 15m rebar with a 2" bend at the end to be set into the May 5, 2021 · I want to pour a 16 x 22 patio from my house foundation (slab) and encasing 3/4 sides of the storm shelter. We first drilled 1/2-inch-diameter holes 8 inches deep every 16 inches along the existing slab edge. You don’t need a form between the existing slab. All Oct 22, 2008 · Then you can pour the slab into the webs of the block after stuffing in some rebar and lock the wall to the slab. Jan 13, 2010 · Existing house with 48″ crawlspace, 8″ CMU on 8h x 16w continuous footing, will get addition. Connect new foundation to existing: Those two pieces of vertical rebar help lock two different pours of concrete together. com) and inserted #4 rebar. Mar 16, 2012 · The sister walls will be reinforced with rebar, but how to tie them into the existing stone foundation?? I really don't want to send any vibrations through the existing walls by drilling holes, so would a bonding agent be better for this?? When pouring a new 10'x15' patio slab next to an existing 6'x15' slab, smooth dowels embedded into the existing slab help align and transfer loads. One way is to drill into the edges of the existing slab and chemset rebar into it to form a strong tie-in point between the two slabs. Addition will have crawlspace foundation of formed and poured 'crete, 8" walls on footing same size as existing. Nov 17, 2011 · Hi friends, I am about to have my concrete patio built in my backyard. I'm getting bids on having a concrete patio poured (approx 600-700sq ft). Learn how to pour and cure your concrete, ensuring long-lasting stability. 5) 16" OC or 24" OC? Thanks! concrete repair Brisbane Click to expand Mar 1, 2002 · If the footings meet the existing foundation, I tie them together with 1/2-in. An engineered schedule of epoxied rebar pins reinforces the joints Irun a design-build company in Chatsworth, a neighborhood in greater Los Angeles. With careful planning and our expert advice, anyone can In this episode of Concrete Edge on Deco-Crete TV, Jeff dives into the age-old question: when should you dowel concrete slabs together? With insights and pra Oct 3, 2001 · what is your take on the use of epoxy to anchor rebars in concrete. It is important to add a layer of 3 days ago · Master the art of placing rebar in concrete walls with our comprehensive guide! This article covers everything from selecting the right rebar type and cutting techniques to essential tools and safety measures. I haven't found any recommendations for capping an existing wall. What the best way to tie the new walls into the old? Is rebar driven into the block to connect the footers enough? Understand the options, design requirements, and common pitfalls to spec the right footings to keep your foundation strong for a long time. Dec 8, 2022 · What is the best connection technique for pouring a new poured concrete foundation addition onto an existing 8" CMU block foundation? I have an 30'x30' addition 8' deep onto the end of a 30' deep home that has an 8' CMU hollow block foundation. Are there tables in the IRC 2012 that give a prescriptive method for doing this? 2 days ago · Learn how to effectively incorporate rebar into your concrete footings to create a strong, durable foundation. It addresses minimum reinforcement and detailing requirements, some of which apply generally to foundation elements and others that are specific to foundation elements supporting the seismic force resisting system (SFRS). Jul 3, 2002 · I am looking for some guidance on determining the bar size, bar spacing, hole diameter and depth for doweling a new concrete section onto an existing concrete section. I've been searching around the Web trying to find recommendations for how to properly tie the new wall into the existing one, but most of what I'm finding is tying new pours vertically into foundation walls or tying new slabs into existing ones. User note: About this chapter: Chapter 4 provides requirements for constructing footings and walls for foundations of wood, masonry, concrete and precast concrete. Discover the right software, tools, and anchors. Ensure your Attaching rebar to existing concrete can be essential for strengthening structures or for new construction projects. Learn how to install rebar with an epoxy anchor into concrete using Hilti’s standard cleaning method. Before I had known that the existing What is Rebar? Rebar is short for “reinforcing bar”. Rebar is most commonly found as either a steel bar or steel mesh inserted into concrete to increase its tensile strength. Standing on a site with a 1970s slab they’re reusing, they share valuable advice on assessing an existing foundation Post-installed rebar is shorthand for reinforcement bars that are installed after concrete has been poured and cured. Install chairs: Chairs can be used to hold the rebar in place while the new concrete is poured. Think of it as giving concrete a backbone—without it, the concrete might look impressive but would fold under pressure like a house of cards in a windstorm. Where applicable, such as in a column, slab, or wall extension, it is generally preferable to place the post-installed reinforcing bars inside of the existing reinforcing bar cage, both to minimi e spalling during drilling and to ensure adequate cover. Dowel the new footing to the original building with at least two #4 rebars. To compensate for concrete's poor tensile performance, steel reinforcement bars (rebar) are integrated into the foundation system. Avoidance of xisting reinforcing is fac 3 days ago · Unlock the secrets to building a durable concrete slab by mastering the use of rebar! This comprehensive guide explores its role in crack prevention, tensile strength, and load-bearing capacity. 4. This application can be characterized This example does not address adding reinforcing bars for shear transfer, if required, between the section enlargement and existing concrete. The slab will be 20'x20', and I plan to skimp on gravel under the slab by relying on the foundation. more I have read mixed things about needing to dowel into the foundation to prevent the pad from sinking and I wasn’t clear on, what the right method is. Rebar epoxied into holes then tied to rebar in the new pour area. This will prevent differential movement between the slabs. Our expert guide explains footing rebar details, sizing, and slab reinforcement tips. Oct 17, 2009 · I'm add an addition to an existing house and need to provide rebar dowels from new foundation and footings into existing. It eliminates or reduces the risk of differential movement between the adjacent’foundation’ sections (new and existing) that could result in cracks or other damage to the structure being supported or the slab structure. Feb 13, 2020 · What is Underpinning? When adding new stories to a property or repairing a faulty foundation, “underpinning” is the process used to improve and strengthen an existing foundation and allow for more load-bearing capabilities. May I ask why you are using block and not a poured wall especially a wall formed with ICF's. Learn step-by-step how to install rebar dowels to securely tie a new concrete slab to an existing one for a durable connection. 3. This step-by-step guide covers tools, techniques, and best practices for stronger, more durable foundations. Should New Patio Be Tied Into Existing Foundation? I'm in Dallas area in a pier & beam 50's ranch. Learn how proper placement enhances strength, load distribution, and durability, ensuring your DIY projects stand the test of time. What do you recommend for the structural tie of new walls to existing, at these tees? Oh, and the existing wall is 8" thick. The foundation walls will be concrete block veneered in brick, same as the existing foundation. Although this approach adds $200 or so to the construction cost, it provides excellent insurance against cracking. The plan was for a new bedroom suite in this added space to tie into a two-story addition that we would build in conjunction with the garage work. Mar 30, 2010 · Do I need to put some form of expansion joint up against the previously poured slab, and should I pin the two slabs together by drilling rebar into the existing slab?? I'm worried when the new slab contract/shrinks back I'm going to have a troublesome gap between the slabs which might create a problem in the area of the wash stall. The best approach is to provide compacted backfill to 95% Proctor density from the footing to the sub-base (see “Soil Compaction Basics,” 3/94). You start the foundation with a footer or footing. In accordance with section 25. Read our guide now! Jan 1, 2007 · As part of a recent renovation project, we added a second floor to an existing one-story attached garage. You’ll need to dig to the bottom of the existing footing, drill it horizontally, and grout in rebars that extend about a foot into the new footing. Not to mention any resulting cracking. When a slab is being poured and the mud is being pushed and prodded into place, standard welded-wire mesh often is trampled to the bottom of the With DEWALT's complete rebar doweling system, you can more easily connect new concrete to existing concrete. I did a similar repair several years ago, but the rebar was epoxied to a failed poured foundation wall and the garage slab was locked in to prevent the wall from moving again. Types of Rebar There are many different types of rebar, and you can find many different shapes and Jan 3, 2004 · 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. Normally a 4 inch reinforced slab is fine for residential hot tubs. Does anyone know how to insert the rebar into the blocks, and subsequently how to pour the cement? The foundation is currently holding two floors. Nov 26, 2024 · Discover expert tips for safely pouring a concrete slab next to your house foundation. Addition will have foundation of formed and poured ‘crete, 8″ walls on footing same size as existing. Oct 23, 2006 · They recommend the rebar protrude at least 3" into the existing foundation (epoxy glued) and about 10" into the new footing/stem. Mar 1, 2007 · Anchor the new slab to the old one. This increases the strength of the new slab and helps keep the two slabs coherent. If it is concrete drill and epoxy rebar is the best. Should the dowel bars be at the top of slab and then into the foundation wall or the dowel at the bottom of slab then into the foundation wall. Build Jul 23, 2011 · I've been doing some research on reinforcing existing unreinforced CMU walls. We cover various rebar sizes, optimal installation techniques, and common mistakes to avoid. Apr 9, 2025 · Learn how to choose the right rebar size and spacing for concrete footings. When you say "tied," you mean, with rebar or similar? That would be a lot of extra work. Discover the types of rebar—steel and fiberglass—and find essential prep and installation tips. These steel rods are inserted into the old foundation and extend into the new concrete pour, creating a solid bond between the Learn how to properly use anchoring epoxy for your concrete repair projects in this Sakrete Pro Tips guide. Is there some epoxy or something I can squirt in to lock the rebar into the concrete? Extending existing reinforced concrete slabs, walls, and columns is a common applications for post-installed rebar. What is the best way to tie the new slab floor of an addition to an existing slab-on-grade foundation? A. Also you don’t need that much concrete. Jan 11, 2023 · Reinforcing a foundation can be done in several different ways, depending on the damage type and materials available. New work, always settles a little bit, and this will help prevent it from ultimately sloping towards existing foundation. My initial thought was to lay cinderblock with rebar every other row that ties into the existing foundation. The contractor states he will drill and place rebar dowel every 2 feet into the foundati Mike’s Total Teardown to Save a Leaky Backyard Studio | Holmes on Homes 503 We're going to put rebar into the existing foundation 340 Dislike 3 Jun 13, 2023 · I'd like to remove these garage doors and fill in the gaps in the foundation, and then add one or two service doors in their place. Feb 14, 2017 · Hi, Id like to know how do you guys suggest to connect existing concrte slab (14 cm thick) with new slab (same thickness). Aug 21, 2018 · Hi all, In case we need to support a concrete slab (patio) and considered it to be a structural slab. We specialize in large-scale remod-els and custom luxury homes. Reply reply rucho • Sep 13, 2011 · The existing foundation has sufficient reinforcement for the modified stresses, and we can reinforce the extension as needed. Reinforcing an existing concrete block wall is an important way to ensure the longevity of the wall structure. Typically, a hole is drilled into existing concrete, and is then filled with an adhesive mortar before a length of rebar is inserted. Steel reinforcement or “rebar” is recommended where the total thickness of the grout is greater than 6” (152 mm). I can't imagine anyone doing that for a patio slab. Mark out the junction on the existing wall, drill away and hammer out Discover the essential role of rebar in concrete slab construction in our latest article. The splices should have at least 2 ft overlap into the new pour. Discover the benefits of various rebar types, including steel and fiberglass, as well as proper footing preparation and installation techniques. The bin sits on a large mat foundation and the dimensions of this new building are very tight to the existing structure. This comprehensive guide covers essential tools, step-by-step instructions, and crucial tips to prevent common mistakes. 1 Post-installed reinforcing bars and their application in construction A common and long-standing application of anchoring adhesives is the installation of deformed reinforcing bars (rebar) in holes drilled in concrete to emulate the behavior of cast-in-place reinforcing bars (Figure 2). The size of the rebar depends on the size of the concrete, with heavier concrete requiring heavier rebar. In this video I will show you how to make a new foundation by connecting the old one with the new one. At two places, we'll tee the new to the old. We’ll detail every step and provide tips to ensure the Placing dowel rebar into existing concrete requires knowing the basics of dowel rebar and a complete understanding of the process. Depending on what type of soul you have underneath the slab the idea that Fix had about adding to deep piers on each side wouldn't be a bad idea. In most cases slabs and foundations are isolated from each Jul 10, 2019 · Rebar was essential for tying the new bench wall to the existing foundation. 5 ft retaining by 1 ft, so will be providing dowels on top of the wall Sep 1, 1991 · Q. The general consensus seems to be that you pop out the face shells, drill and dowel into the footing and into the bond beam at the top, place the reinforcement and then grout the cells. 1. 1, the hooked rebar has sufficient development length in the new concrete. tovokrw hkjo6e rcuhllj j3e 9bqu rru1u et ml g7e o4xpo