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Pouring new concrete slab next to old concrete slab

A. You can join the new concrete right to the old concrete, this is called a concrete construction joint. The edge of the existing concrete that was sawed should be drilled and doweled so the new concrete won't separate, lift, or settle from the old concrete You can add new concrete to an existing concrete slab if the old concrete is in good condition. You will need to thoroughly clean the old concrete surface and use a suitable concrete bonding agent before pouring the new concrete to satisfy all structural requirements By foundation, do you mean just a concrete slab? I would try to tie the two together by drilling holes horizontally into the existing slab and inserting some rebar into the holes. How much effort to spend depends on the soils below and what you're going to do with the shed A well-poured concrete slab with a deep, sturdy foundation can last for 30 to 40 years. Pouring concrete over old concrete instead of directly over a new gravel foundation limits your ability to maximize the slab's lifespan. The condition of the existing slab is the primary factor that determines how long the new concrete will last Adding fresh concrete is a common way to level out old slabs and patch damage. If you plan on pouring a lot of concrete, build a wood and mesh barrier first to ensure your new slab is strong. Finish the work by priming the surface and pouring a mix over it, giving your concrete foundation a fresh, new coat. Part

How do you join new concrete to old concrete

  1. Another option is to use a shelf angle to support the edge of the garage slab (B). We usually recommend a continuous 3x3x3/8-inch steel angle, bolted to the concrete foundation wall every 16 inches with 1/2-inch-diameter bolts. However, this will support only the slab edge, and will not prevent distress cracking that may occur as the soil under.
  2. I will need to pour concrete against the existing structure above the top of existing concrete, mostly for the porch. The top of the new concrete would have to be a max of about 5-6 inches above..
  3. Then mix the concrete and fill the hole. Use a 2x4 to screed the top even with the existing slab. The tricky part in then floating the top so it's smooth. After it sets so it's firm, cover it over with plastic so it dries slowly. You can dampen it down the next day to slow the curing process and recover
  4. Re: Concrete slab next to concrete slab? If you want to ensure the slabs say on the same plane over time epoxy smooth 3/4 dowels into the edge of the existing slab, make sure you have at least 1-1/2 cover (2 or more is better, aim for the center or slightly below), then grease the exposed ends of the dowels so the concrete won't bond to them
  5. Run a bead of concrete epoxy on the face of the edge of the first concrete slab, above and below the dowels. Cut your expansion joint material with a box cutter so you can press two strips onto the concrete (above and below the dowels) the entire length of the edge. You are now ready to pour your slab
  6. es the condition of the new concrete
  7. We have a 10 year old patio that was poured up against our brick facade. Since the slab settled, and our house didn't, there are huge cracks all along the points where they meet. Apparently, this was the second attempt by the PHOs to make a patio. Nothing like tearing up a mistake made of thick concrete. ;o

The resources required to remove a slab of concrete can include a sledgehammer, shovels, wheelbarrow, lots of safety equipment, and of course, working hours. If possible, it would be ideal to avoid this hassle altogether by pouring the new concrete slab right on top of an old one Clean the old concrete First - pressure wash it, vacuum it, remove any dirt, debris, or loose concrete. If you're new concrete is under 3 thick, apply Weld-Crete, let it dry at least 1 hour, then you're ready to pour your new concrete Immediately before placing new concrete apply a cream consistency made up of Portland cement and water. Brush it in with a broom. Apply the new surface concrete and cure properly. I've cut cores from the completed job and with a cold chisel try to break at the bond, Never have had the break there It is a difficult process but you are basically stitching the old slab together and also to the new slab. However most contractor will simply come out and place a rebar mesh on small pedestals above the existing floor and then pour enough concrete to level the area and cover the rebar mesh

Pouring concrete over old concrete instead of directly over a new gravel foundation limits your ability to maximize the slab's lifespan. The condition of the existing slab is the primary factor that determines how long the new concrete will last. If the foundation beneath the slab is not sound, the new concrete could sink or develop deep potholes The existing slab on grade slopes to drains and owner wants to level the floor by pouring an additional 5+ concrete slab on top of the existing slab on grade. The literature that I found regarding reinforcing of slab on grades states that the amount of reinforcing is directly proportional to the friction between the concrete and the soil 1-drill for rebar2-epoxy 63- insert Ur rebar4- new concrete i How I poured a concrete slab over an existing concrete porch slab. This is video #3 of my porch to room addition series. My objective was to create a new lev..

Can You Pour New Concrete Over Old Concrete

Pouring new concrete next to old - Houz

If you are pouring 4 have them break it 5 high. As you install the metal, shoot some silicone caulking behind it. Just nail it with roofing tacks enough to hold it until the concrete is poured. I always wait until the last thing, just before I pour the concrete because the weight of it will spread out the silicone a lot better than any other way You are planning to place a 4 inch thick slab. American Concrete Institute (ACI) recommends a minimum clearance of 2 inches between the edge of a bar and soil, and 1-1/2 inches between the face of concrete and the bar. So in a four inch thick slab, the bars are forced to go essentially at the center

Being the old slab is in pretty good condition you can pour directly over the old slab with 4-5 of new concrete. Use a 6x6 10x10 welded reinforcing wire in the new concrete to help prevent. They poured a monolithic slab then cut in the joint, there is now a hairline crack just past where they cut, that's the purpose of the cut, to direct the cracking. However the large chunk missing at the downspout is shoddy. Looks like there should have been more concrete around the downspout or it shouldn't have been in the concrete at all Slab beim führenden Marktplatz für Gebrauchtmaschinen kaufen. Nr 1: Mehr als 7 Millionen monatliche Besucher und 8.100 Verkäufer vertrauen uns bereit The new slab would raise the main floor elevation 12 to allow for new ground works and hydronic heating and would have a 12 x 12 footing on the perimeter with 1/2 rebar dowelled in on 16 centers and be backfilled to allow for a 4 slab on top. The question that is coming up is in regards to the new/old concrete bond and potential moisture. You must form on top of the existing slab and drill in anchors to join the new concrete to the old this is called a cap How many yards of concrete it will take to pour a concrete slab that is 24ft.

Pouring Concrete Next to Existing Concrete. You may choose to enlarge an existing pad, or cut out weakened concrete from structurally sound, and pour new material. Pouring concrete so it joins the old and forms a strong bond can be done in different ways Most of the time a slab would be 4 inches, so you would pour the same 4 inches over the old slab as you would install on a new base. You would have to pour more than 4 inches for the rest to come to the same level, since the base will likely be lower than that of the old slab. So this is already more concrete than an new slab Pouring interior concrete slab over existing, cracked concrete slab [ 4 Answers ] I am turning part of my carport into a new living room. I am going to pour a concrete slab about 4 inches thick over the existing carport floor which is a concrete slab. The existing slab has a few cracks, the largest of which is about an 1/8in The waterproofing layer between is most likely to stop moisture from the new pour being sucked out into the existing concrete and weakening the new slab. The worst that could happen would be if the new slab ever lifted due to soil swelling under the new section and created a gap underneath between new and old

The Disadvantages of Pouring Concrete Over Existing

  1. The masonry foundation or the slab should also contain structural steel. Dual horizontal steel bars 12 to 16 inches from the top and bottom of poured concrete foundations help to create a stiff concrete beam. Concrete block foundations can incorporate steel truss fabric that is installed in every other row of the concrete block units
  2. Much like stamped concrete, stamped overlays are an efficient and sharp way to resurface exterior spaces, adding a new layer atop old, damaged, or weathered surfaces. Stamped overlays make it easy to mimic the surface (slate, stone, brick, wood) already planted in the ground
  3. Also, two weeks after pouring, use a masonry saw to make cuts one-third of the way through the thickness of your concrete slab. Make these cuts in a 10-ft. x 10-ft. grid pattern. Make these cuts in a 10-ft. x 10-ft. grid pattern
  4. imum clearance of 2 inches between the edge of a bar and soil, and 1-1/2 inches between the face of concrete and the bar. So in a four inch thick slab, the bars are forced to go essentially at the center

Video: How to Add Concrete to Existing Concrete (with Pictures

Fiber reinforced toppers go from 1/8″ for non-wear to 3/4″-1″ for wear surfaces. Lightweight and regular concrete toppers tend to be about 1.5″ and do contain wire mesh reinforcement. So, back to the question, how thin can I pour concrete over existing? Depends on your criteria, but if you don't know, go with 1.5″ lightweight with a. Depends if your pouring a veneer or a new slab. not specific enough so I'll just give you a general answer, when pour new over old. The old surface must be cleaned and scarified. If it were a slab you would treat the old concrete as the foundation and simply pour over it. If it were grade beams and structural work , your going to have to.

We bought a foreclosured house in Houston area. It's our first house, a 12 yr old house. The house is on a slab foundation. One thing we noticed that the corner next to the front entrance is like a little pond when it rains. At that corner, the inside wood trim shows decay Spraying water on your new concrete is one of the best and oldest ways to cure your concrete. After new concrete is poured and finished the concrete begins its curing process. The best cured concrete is concrete that is cured slowly, uniformly, and evenly from top to bottom. During the summer months, the outside temperature can become hot

Q&A: Supporting a New Slab Next to Existing Foundation

Depends if your pouring a veneer or a new slab. not specific enough so I'll just give you a general answer, when pour new over old. The old surface must be cleaned and scarified. If it were a slab you would treat the old concrete as the foundation.. Typically when I pour concrete against a house foundation, (never pour concrete against any siding IMHO, it invites trouble later) I have an expansion joint set to the house. It can be cork, 1/2 thick by 4 tall set to the wall with short pins to hold it while pouring Concrete control joints should be no less than ¼ of the total thickness of the slab (1 deep for a 4 thick pour) and placed no less than 2-3 times (in feet) the thickness (in inches) of the slab (8-12 feet apart for a 4 thick pour). Control joints can be created while the concrete is being poured by using a tool to make the joint Q. I am renovating a barn where the existing concrete floor slopes approximately 6 inches in 30 feet. The architect wants me to build a level floor using wood sleepers with foam insulation in between, then pour a minimum 1 1/2-inch-thick radiant slab between the sleepers. The finish floor will be slate.Instead, I recommended pouring a new level slab over the existing slab and installing the.

In order to keep your new slab of concrete at an acceptable temperature, usually between 50 and 85 degrees F, and at an acceptable moisture level, which varies, you'll need to use the three phases of curing. Starting immediately after pouring the slab, watch the bleed water that rises to the top of your concrete The next critical part is the placing of control joints (the notched grooves in concrete). You need to place them at a maximum of 10′ apart in the pour in both directions. You should just have 1 in the center running from the street to the garage slab, and the perpendicular ones not exceeding 10′ Slab Demolition and Pouring the New Slab. April 24, 2013 · by mattbyers777 · in Foundation . ·. I am confident that I am able to form and pour a small concrete pathway or patio without too much concern. Accurately placing nearly eleven cubic yards of concrete, however, is a rather daunting proposition. With concrete, unlike framing, if one. When pouring a new walkway or small patio that abuts a house or other structure's foundation, always consult local building codes for guidelines on pinning or knitting the new pour to the existing foundation. In most cases, the new slab should be left separate from the foundation to allow slab movement My new house, built on a concrete slab, is about 60% done, framing and drywall are in. My concern is I have several hairline cracks throughout the slab. I purposely had the slab made thicker (6 inches) with heavier rebar and a fiber- type additive to hopefully minimize this from happening

I want to increase the size of the concrete slab floor from my old shed for my new sauna , the existing floor slab is aprox 2.4 x 1.8mtrs. and I wish to increase the size to 2.4 x 2.4 mtrs.It will not have any thing heavy on it but will have to deal with water and heat from the sauna Pouring concrete if the weather is too cold: poor chemical reaction in the formation of the concrete will mean weak concrete. Freezing, not a problem in your Texas concrete pour, also causes weak concrete. On 2020-08-23 by EricDoty. New 32x36 slab poured in Texas heat, [Photo above] concrete poured at 0900 and work finished and forms removed by. Pouring Concrete Slab in Existing Garage w/DIRT FLOOR - Cost??? Hello everyone! I've been hunting around trying to wrap my brains around a way to get a floor into my 100 year old garage. Its a 18.5'x18.5' (inside dimension) garage with a dirt floor. There is a fieldstone/mortar foundation around the perimeter with 6x6 beams on top of the.

New concrete next to existing foundation - Forum - Bob Vil

Concrete slab, build on less than 48 hours of pour. jhaynes (Jeffery L. Haynes) January 7, 2011, 11:58pm #1. Doing a phase inspection, my client specifically instructed the builder to contact me prior to pouring concrete (he was suppose to provide me his flow schedule)needless to say that didn't happen. As they were pouring I was. When laying new concrete over an existing slab, it's important to separate the two layers. This is because if the new layer is poured directly onto the existing slab, the two slabs will bond together. If the slabs bond together, any cracks or damage in the old surface will spread to the new surface. Concrete slabs will also shrink and expand.

Pouring Concrete Slab Next To House FoundationHOW TO DOWEL INTO CONCRETE - YouTube

new concrete floor next to old concrete floor DIY Home

Pouring concrete over an existing concrete slab - How to bond them together They always say Rome was not built in one day, and this was the place that changed the looks of architectural structures that we see today. Hydraulic cement-based concrete.. The Concretene was used in an initial pour of a concrete floor slab for the new Southern Quarter gym near Stonehenge in England in early May, with a second pouring completing the foundation on. These structural cracks in concrete slabs occur due to a combination of natural and artificial factors that are described below. 1. Settlement Cracks. Settlement cracks develop when the loosely aggregated soil beneath a concrete slab gets eroded or settles. Since the soil has settled some areas of the concrete slab are unsupported and can crack. Q.: Two similar questions have been raised regarding placement of concrete on top of recently completed slabs and footings. In one case the contractor wanted to form and place his basement walls the day after completing the footings, but was being required by the architect to wait 7 days

Concrete slab next to concrete slab? - JLC-Online Forum

Next was to screed the surface. This means to go across the surface of the slab with a 2×4, using a sawing motion. This removes the extra concrete while also filling in the voids. We had to do multiple passes (about 4) to get all the areas filled in. Now let the slab dry some Good strong and high-quality concrete is achieved by using the right amount of water in the mix and an experienced team that has right amount of manpower to be able to use a slightly dryer stiffer concrete mix .more expensive I guess but a that's the price of getting a great concrete slab and one you wish you ripped up and redone When to Saw-Cut Concrete . In addition to the concrete mix and the weather conditions, determining when to saw concrete is based on the concrete's hardness as well as the type of cutting equipment used to make the saw cuts. Cutting too early causes raveling, an effect created by the saw blade pulling the aggregate out of position, leaving a messy, weakened edge along the cut Answer 1 of 2: The old quip about the only things certain in life are death and taxes could be added to: and concrete will crack! Concrete cracks for a variety of reasons, but the most common one is normal and not a durability or structural problem: shrinkage. Water is necessary for concrete to cure (it does NOT dry, it is a chemical reaction called hydration), but we will add more water than.

How to Join Two Concrete Slabs Hunke

The next thing to do is to make sure that the concrete floor surface is thoroughly wet and paint the whole surface with a bonding adhesive. Pour the concrete onto the existing damaged concrete in the same way and trowel to a smooth finish and hopefully there is no more rain to cause any damage. The new slab can be walked on in about 12 hours. If done properly, new concrete can often be poured right over an existing slab. For this to be feasible, the contractor needs to pour at least 2 inches thick, use smaller aggregate, and incorporate reinforcement such as welded wire mesh or fiber mixed into the concrete. Steel rebar is also a good idea if the slab is thick enough to allow it Method Statement for Pouring Concrete on Slab on Grade. After backfilling works the next is casting slab on grade (ground), make sure that all the area beneath grade slab have been properly backfilled and compacted. Approval must be obtained from the Engineer for waterproofing and backfilling works prior to start slab on grade casting A tree expert came out and recomended NOT cutting any roots (the tree destroyed the old footing, and the new slab will be within six inches of the trunk of the tree, as was the old building). My guess is that if the tree recieved water from its roots in that direction it was in spite of the old shed and thus a new one would be O. K Concrete is poured with expansion joints that allow room for the pavement to expand in hot weather. These joints can turn into cracks in the asphalt, which will necessitate expensive and time-consuming repairs. Your best bet is going to be to tear up the old concrete before pouring the asphalt. Call Tucker Paving for Your New Driveway

Can you put new concrete over old concrete? All Pro

Placing New Concrete Over Old. For this to be feasible, the contractor needs to pour at least 2 inches thick, use smaller aggregate, and incorporate reinforcement such as welded wire mesh or fiber mixed into the concrete. Steel rebar is also a good idea if the slab is thick enough to allow it If you don't need to move the drain location in the concrete slab, then all you have to do is use the KBRS prefab foam shower pan drain kit. Either the standard type drain or a trench drain. If you need to move the location of the drain in the concrete slab, you will have to chisel out the old one and open up the path to the new location

concrete being poured against the house - Fine Homebuildin

Next, we covered the insulation sheets with polyethylene foil, so the concrete doesn't get between the sheets and thus compromise the thermal efficiency. On top of that we set rebar mesh to make the concrete slab really rigid and prevent it from sagging. The last step before pouring the garage floor is to check if it's level A slab foundation is made of concrete that is typically 4-6 thick in the center. The concrete slab is often placed on a layer of sand for drainage or to act as a cushion After completing over 150 concrete slabs in the last 30 years, below are our recommendations for the best practices when constructing a new concrete slab. A. Preparation and documentation. Study the soil report and review the soil / ground conditions with your builder. Specifically discuss any potential cost variations due to site. Pour this mixture in a small 1-foot by 1-foot form and finish it where the top texture matches the existing concrete as close as possible. Cover the test patch with a new plastic garbage bag and secure it so it doesn't blow off. Wait for two weeks. At the end of the waiting period, mix one part of muriatic acid to ten parts water Because its the easiest quickest way to do the form work. Just lay a 2X4 on the ground with the 3 1/2 side vertical and boom instant form. Do remove the grass first. And I'm about 99.9% (unless it is off the ground) sure your house isn't on piles. Don't tie your new slab into the house foundation

Can Concrete Be Poured Over Old Concrete

But, for many patio slabs that have settled, tearing out the old slab and pouring new concrete is not the best approach. Full concrete slab replacement is more expensive - sometimes significantly more - than other repair methods. It's also much more disruptive and time-consuming One concrete guy told me he could just pour new concrete over it. Another guy (a real company, not just a guy) says it should be dug up and done completely new. The first guy wants about $1000, the second one $3000. I know with the second one part of the expense is demoing the old walkway, then bringing in the pounding machine and concrete truck Re: Tying In Ajacent Concrete Floor Slabs. Even with footings at the perimeter of the new slab, slabs on grade often settle. Rebar dowels is a good idea. Regarding the joint between the two, the new concrete will shrink and there is also some expansion/contraction of concrete due to changes in moisture or temperature

Concrete Basement Flooring and Repair in Bangor, Portland

Can You Pour Concrete Over Concrete - How To Pour New Over Ol

Joints are used in areas where two slabs of concrete meet, when a slab meets another concrete structure like a wall or when a span of concrete is overly long. For example, a 100 ft. concrete sidewalk wouldn't be poured in one long slab. You'd get lots of cracks. Rather, we cut expansion joints which breaks the sidewalk into smaller pieces Building New Slab Over Foundation Rubble. Kevin writes: In 2013 we decided to demolish our existing home (build in 1941) and build a new home in the same place. Because our neighborhood is built on 85-foot-deep clay over a glacial lake, the old cinder block foundation had failed in the basement and we had serious moisture problems as a result Why Would Holes Appear on a Brand New Concrete Driveway?. Concrete is a mixture of sand, crushed stone or gravel, and a paste consisting of water and portland cement. It becomes stronger and.

Pouring new concrete over exisitng - Structural

New concrete can look dry well before it is ready to be coated. Additionally, as a result of how the concrete was mixed and/or differences in site conditions, different areas of the slab may have vary in their moisture levels. Therefore, testing several areas for moisture/moisture vapor is the only valid way to tell if the slab is ready for. When working with cement-based products, always wear eye protection and waterproof gloves. Step 1. Prior to placing concrete forms: Construct the form with 2x4 or 2x6 lumber and secure in place by wood stakes and deck screws. Excavate the slab area to a depth of about 7 inches, allowing 3 inches for a gravel base and 4 inches for concrete. Step 2 Joined Dec 5, 2008. ·. 1,205 Posts. #2 · Jul 6, 2011. the concrete in the ground anchors the post evenly. the concrete around the post at the top (slab or patio) will cause two problems, 1 it makes a weak spot that will crack or 2 as the cocrete expands and contracts with the weather it could shear the post and cause the structure to fail This project involves most types of transitions that consist of a variety of joint combinations and slab configurations. In many instances, the performance of the transition areas may become the focal area for maintenanc

Step 7: Concrete Slab

Large concrete slabs are typically divided into sections by expansion joints, which help control cracking. The ½- to ½-inch-wide joints are usually filled with asphalt-saturated felt, a wood 1x4 or plastic channel. These joints must remain exposed to allow the slab to expand and contract; don't cover them with the cement top dressing 1. Pour concrete when the temperature will be above 50 °F (10 °C) for at least 7 days. Concrete cures best in temperatures above 50 °F (10 °C), so check the forecast for the next week. If you can expect warm temperatures, then now is the right time to pour the concrete 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 crushed stone under the concrete. The crushed stone provides a capillary break that reduces the amount of moisture flowing upward from the damp soil to the permeable concrete. Since the crushed stone layer. Once the concrete has been poured, it needs to be leveled and smoothed. Expansion grooves should be cut into the wet concrete to provide additional crack resistance. Then, the new slab needs to be left alone. Concrete doesn't dry out; it undergoes a chemical curing process that creates a dry, solid mass