The Science of Concrete

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The Science of Concrete

While concrete has been around for thousands of years – the building material of choice for ancient Egyptians and Romans – the quest to make concrete stronger, more resilient and longer lasting continues.

Providing the highest quality concrete for our commercial and residential construction projects is paramount to Custom Concrete. We work with reputable, long-standing ready-mix concrete companies like Shelby Materials to provide us with the best product for our foundations.

Chris Wolf, director of technical support for Shelby Materials, weighs in on “The Science of Concrete” this month.

Think of concrete as a very slow setting, two-part epoxy … and by “very slow,” I mean close to four weeks. The sand and stone are just fillers; the action is all about the water. When we make concrete, we add water and cement in the correct proportions. If the job requires more fluidity, we add water, but we don’t always add cement. Adding water is like adding more hardener than the epoxy needs for balance. The qualities are reduced.

The same thing is true when we fail to take steps to keep the water in place during curing. The cement is bound by gravity and never leaves, but the water can evaporate. Some days are cloudy or humid so the water leaves very slowly. Other days are dry, sunny and windy. On those days, the crews are adding water as fast as they can. In my position, I hear owners ask, “Why is my concrete different than everyone else’s?” Water is the “why.”

There is one more problem. The two-part epoxy of cement and water is a chemical reaction. Like all chemical reactions, it is dependent on temperature. So colder is slower, and hotter is faster. In summer, hydration is very fast. We often have full design strength in a few days. However, crews struggle to keep up with the setting of the concrete. A good foreman has extra man power to keep up with demands of the concrete. When we make summer concrete, we add ingredients to help them like fly ash and admixtures. We cannot reduce the cement content or that would upset the balance of the “epoxy.” Fly ash is a very effective retarder. It is also very cementitious. Fly ash is a waste product of our coal fired power stations. Power stations are very efficient, so the fly ash we receive is very consistent. Using fly ash is environmentally friendly and beneficial.

The big problem is in the winter. In winter, the hydration is very slow, and thus, strength gain is slow. Set time is slow. The need for curing and protection is critical. The concrete is “green” longer. It is more likely to lose water to dry winter air. Furthermore, winter includes freezing rain, ice, and snow. All of these damage concrete that is not yet strong. As a producer, we have sand heaters, we remove fly ash, we add more cement, and we have accelerators. All of these tools help the crews give the concrete a head start.

The thing to remember is that water is part of the strength of the concrete. We must take steps to keep water in the concrete so that it can hydrate with the cement to give us the strength and durability we paid for. Curing is critical.

Healthiest Employer 2015

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Custom Concrete Named Healthiest Employer

Westfield, Ind.-based Custom Concrete recently received recognition with the Healthiest Employer award for all Central Indiana companies with 100 – 499 employees. The award honors companies and organizations that take employee health seriously by offering wellness programs that are thorough, innovative and make a difference in the lives of employees and their families.

Custom Concrete’s nomination was in direct correlation to the company’s philosophy that wellness is a marathon, not a sprint. Their wellness program touts a very high participation rate and seeks to inform, educate and facilitate a healthier lifestyle both at work and at home for their employees.

According to Custom Concrete’s Chief Operating Officer Doug Staebler, being a healthy employer is a win-win proposition. “Less than three short years ago, we were just beginning the journey and trying to determine how we could help our employees achieve meaningful improvements in their health as well as for their entire family.  The notion of corporate wellness was not at all common for contractors, but we were convinced that we could help our employees through a combination of education that was both fun and effective, as well as offering financial incentives connected to our group medical insurance plan,” he said. “We have had outstanding guidance and support from American Health and Wellness along the way.  Our employees have embraced the wellness program which is now a big part of the culture at Custom Concrete, and we look forward to new wellness initiatives as we move forward.”

The company is currently creating a “path to wellness” in conjunction with the city of Westfield. Custom Concrete is located adjacent to the Monon Trail in Hamilton County and the location offers a healthy commuting alternative to driving.

It’s Not Your Dad’s Apartment

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Multi-Family Housing Boom

Upscale, multi-family housing has grown into a hot commodity in Central Indiana, and Custom Concrete’s commercial division has been busy meeting the needs of demand.

According to DTZ (formerly Cassidy Turley), the Indianapolis multi-family market registered 405 units of net absorption during the first quarter of 2015, an increase of 63% over the prior year’s first-quarter absorption tally of 246 units. That figures into more than five years of uninterrupted occupancy gains in Central Indiana.

Likewise, the vacancy rate holds steady at six percent, and the development pipeline in greater Indianapolis remains full with nearly 4,000 units currently under construction, 3,263 of which will be delivered in 2015.

One of those first-quarter deliveries included The Hamilton Luxury Apartment Homes, a 233-unit development owned and managed by the J.C. Hart Company, one of Central Indiana’s leaders in the upscale multi-family market since 1985. Custom Concrete has worked with the company for the last half-dozen years, first with basements and foundations and most recently with flatwork and multi-tenant commercial slabs, earning them status as a preferred provider according to company president John Hart.

“Today’s apartment dwellers are seeking something that lives more like a condominium with more detail door and window treatments, larger bathrooms with over-sized tubs,” says Hart. “Of late, we’ve concentrated on hard surface counter tops and laminate flooring.” One thing he notes has remained popular with those leasing J.C. Hart properties since 1985: direct access garages.

Despite the last five years’ growth, Hart maintains the market has not reached a saturation point. “We strive to design a product that crosses over a number of demographics from the entry level renter to the baby boomer,” he says. “While there is a spike of permits over the last year or two, the last five years’ permits has underserved the market by about 2,000 a year – so we are really catching up to get supply back in line with demand.”

This philosophy and reputation for a quality product have enabled J.C. Hart to weather times of economic uncertainty. “We have historically tried to keep moving forward … when times are good and not as good. Our business is cyclical; it takes so long to build a community from inception to zoning to construction. It’s three year cycle at minimum,” says Hart. “It was hard to predict three years ago what it would be today. With great locations, one-of-a-kind design and outstanding people providing excellent service, we feel like we can thrive in any market.”

 

Commercial Slab Projects

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All Commercial Slabs Not Created Equal

Those in the business of concrete know the importance of a flat and level slab. Especially in industrial warehouse settings, where unmanned forklifts rule the floor and goods may be stacked on shelves 20 feet or higher, flatness and level specifications are a key indicator of project success.

But other businesses are catching on. Flatter and more level floors have been shown to be lower maintenance and provide an improved operational surface for many types of businesses. As a result, the demand for flatter floors is being seen in many different types of projects, from warehouses to retail store operations.

The degree of a slab’s flatness is expressed by two numbers, the FF (which describes the concrete slab’s flatness) and the FL (which refers to the slab’s levelness). Flatness is how close to geometric planarity a slab approaches. Flatness numbers run on a scale from 10 to 150, and most slabs fall into the range of 15 to 100. The higher the FF number, the flatter the slab.

Levelness is the amount of slope (or pitch or tilt) in a slab.  This is the degree to which the surface of the slab approaches true horizontal perfection.

These numbers aren’t only telling of the flatness and levelness; they are also indicative of the quality of work. Floor flatness and levelness are determined by the skill of the concrete forming, placement and finishing crews, as well as the quality of their equipment. The floor levelness is most affected by form quality and the method of strike-off. Forms should be straight and sturdy to resist bowing and warping. Placement is affected by the manner of screeding (leveling) selected. Wet screeding without rails, is typically capable of producing FL values no higher than 18. Screed rails and vibratory screeds can achieve FL ‘s in the mid to high 20s. Laser screeds – as used by Custom Concrete — can reach as high as 100.

Commercial projects specify the desired FF and FL values within the project contract. The average retail floor is FF 25 and FL 15; a general purpose industrial warehouse is typically from FF 50 / FL 35 to FF 60 / FL 40. Custom Concrete’s commercial division consistently exceeds expectations and delivers well beyond the required FF and FL values. Some notable projects include:

  • Subaru warehouse in Lebanon, required FF 50 / FL 35 and Custom Concrete achieved FF 80 / FL 54
  • Project Steel in Greenwood required FF 50 / FL 35  and Custom Concrete achieved FF 91 / FL 49
  • Fastenal in Indianapolis required FF 50 / FL 35 and Custom Concrete achieved FF 69 / FL 45.

We are proud to utilize our nearly 50 years of concrete experience to deliver these high-quality projects.

For more information about our commercial division, contact us here.

Awards from the Indiana Ready Mixed Concrete Association

Suburu Project Description:

Subaru Award

Award-winning Subaru project team

The project is located in Lebanon Indiana about 25 miles north of Indianapolis Indiana on I-65. The project scope requirements were 3,500 lf of building footing, 280 structural column pads, 715,000 sf of 7” and 8” slab on grade, 135,000 sf concrete dock aprons, 1,000 lf of dolly pads, and 8,000 sf of sidewalks. This project schedule was to pour 23,000 cubic yards in 5 months with 50% to be completed during the winter.

Project Summary:

Primarily, Custom Concrete is known in the Indianapolis market as a residential foundation and wall contractor. Custom Concrete was awarded the 715,000 square foot warehouse on the basis of professional referrals, team experience, and budget. The highest slab on grade tolerance specification was to be an FF 60 / FL 40. The tolerance was exceeded and reported as an overall value of FF 80 / FL 54. The largest single pour was over 60,000 sf and more than 1,400 cubic yards. This project was the first large scale commercial project for Custom Concrete in over 40 years of business. On time and on budget! 

Fastenal Project (166,500 sf)

 Significance

This project was started on 12/19/2014 and went through a record winter with regards to temperatures and snowfall.

Fastenal Award

The award-winning Fastenal team

During construction is was found that the precast supplier was unable to deliver the wall panels on schedule so Custom Concrete was asked if they could cast in place the exterior 18’ tall wall.  Custom Concrete accepted the challenge and poured 500 lf of 18’ tall exterior building wall when temperatures ranged from 10 degrees to 35 degrees.  We used self consolidating concrete to achieve the exceeded strengths.

The floor slab was poured from Jan 20th to April 15th all in open air conditions.  Ground heaters and blankets were used to defrost the sub grade during this time frame.  We had over 38” of snowfall that was removed from the building pad during this timeframe to keep the project on schedule.  We achieved an overall FF 69 / FL 45 from the required FF 50 / FL 35.

The exterior was poured in concrete paving for a total of 98,000 sf.

Highlights

  1. CIP wall pour when originally was to be precast
  2. 38”+/- of snow removal by Custom Concrete during construction
  3. FF 69 / FL 45 achieved (open air pours in record winter)
  4. Temperatures from
    1. Working temps from -13 degrees to 65 degrees
    2. Pouring concrete from 18 degrees to 65 degrees
  5. Weather days lost of 22 days
    1. Made all but 6 days up from overall schedule
  6. Numerous design changes throughout the project with no loss of production/schedule days
  7. 7,175 cyds poured in winter

This project was very challenging for everyone involved do to the record low temps and snowfall amounts during construction.  Custom Concrete worked through some of the most challenging worksite conditions and was still able to bring the project in on only 6 days after the original schedules end date.

Project Steel (100,000 sf)

Significance

This project was Custom Concrete’s first project with The Peterson Company.

The floor slab was poured in (3) pours averaging 33,000 sf at 7” thick  We achieved an overall FF 91 / FL 49 from the required FF 50 / FL 35.

Highlights

  1. FF 91 / FL 49 achieved
  2. 2,960 cyds poured

 

Custom Concrete | Commercial Market

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Custom Concrete Expands into Commercial Market

For more than 50 years, Custom Concrete has been exceeding the expectations of its customers by creating top-quality, reliable foundations and forming solid professional relationships through our attentiveness and punctuality. In recent years, we’ve taken those high standards of quality, skilled employees and specialized equipment, to the commercial market. In the past 24 months, Custom Concrete has employed a Team with more than 100-plus years of combined service that specialize in numerous areas of commercial projects.  We have completed a number of large-scale distribution facilities that total more than 1.4 million square feet and currently have more than one million square feet in current projects.

Throughout these projects, we’ve employed our tried and true processes and procedures to handily meet any challenge presented to us and worked tirelessly to ensure our customers’ satisfaction — not only with the finished product, but also with the process of planning and coordination. Our success is no accident – it requires a combination of the right equipment, specialized and skilled employees, proficiency in oversight that employs internal quality control for every job. Perhaps our greatest strength is the adaptability of Custom Concrete that allows us to deliver an unparalleled finished result.

Our customers are quick to agree. “It was a pleasant surprise to find that safety was a non-issue; all our milestone dates were met and the rather tight tolerance on slab flatness were exceeded. Instead of Custom Concrete being a risky hire they turned out to be one of the strongest members of our construction team!” says Craig Hetzer, Senior Project Manager for Gordian Design & Construction, “The Custom Concrete team of Jason Kiser as project manager and Casey Harvey as site superintendent was diligent and accountable through the entire project.”

As we expand our horizons in our commercial concrete division – including multi-family housing — we look forward to new challenges and triumphs. We are committed to continually improving our company and discovering new ways we can better serve our customers and partners. Thanks to our incredible team, we will no doubt continue to exceed expectations and set the bar for quality commercial concrete in Indiana and beyond.

Healthy Concrete

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Simple Maintenance Keeps Concrete Healthy

Every now and then, we receive a rather frantic call from a customer who has discovered a small crack in their basement floor or a drip of water running down the basement wall.

Ninety-nine percent of the time, we are able to assure them this is nothing with which they need to be concerned. Everyone together now: Whew!

A few, small shrinkage cracks in both walls and slab concrete are normal and even expected. We advise homeowners to monitor them just to make sure they are not getting wider or leaking.

That said, there are a few things homeowners can do as routine maintenance practices to keep concrete as happy and healthy as the day it was poured.

1)   Invest in a battery back-up for the sump pump if you live in flood-prone areas. And change out the sump pump every five-to-seven years. Few homeowners realize this and discover it only after it’s too late … and the basement contents are floating.

2)   A good dehumidifier is a must in ANY basement.

3)   Don’t shut off the heat/cooling exchanges in the basement! You need to maintain good circulation with your HVAC system or you will have stale, stagnant air. Yuck.

4)   We’ve said it before, we’ll say it again: Maintain a positive grade! That means that the grade falls away from the house. And while you’re at it, make sure those downspouts are draining a few feet out, away from your foundation.

5)   Mulch should NOT exceed four inches below the top of foundation wall. To do so is asking for water to spill over the foundation wall and come right into your basement.

6)    Concrete, especially in the drive way, needs to be sealed with high quality concrete sealer to prevent ice and salt damage and re-seal as needed. We believe the sealing work done by reputable companies like Midstate Sealing www.mid-statesealing.com provides the best results. Resist the temptation to run down to the nearest big box and buying a sealing kit. If you insist on doing it yourself, go to a concrete store or a company like Midstate Sealing to purchase the sealant.

7)   Snow and ice are no friends to concrete. (Who IS a friend to snow and ice? Never mind.) Try to keep the driveway and sidewalks clear of snow – especially under garage doors – to allow for freezing and thawing. NEVER use de-icers like salt or “melt” products as they are corrosive to concrete. If you need traction, use kitty litter or sand.

Following these simple maintenance tips will ensure your basement and other concrete will continue to bring you enjoyment for years to come.

 

Drainage Issues

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Now’s the Time to Correct Drainage Issues

With the recent onslaught of afternoon thunderstorms (we’ve gone from Michigan weather to Florida weather in the course of a few days!), you may have noticed a little water in your basement. This may be the result of an insufficient slope away from your foundation or a sump pump that’s not in good, working order.

Typically graded during the initial sod installation, your grass may develop low and high areas from hidden underground piping or decomposing tree stumps that can negatively affect your yard’s entire slope. As a result, your lawn mowing is uneven and standing water accumulates in the low areas … or, even worse, runs into your basement or crawlspace. Correcting the grade involves filling the low areas with soil so that your yard has a continuous slope. And, you’re in luck. Now is the PERFECT time to tackle this task – during those weeks when grass is still vigorously growing and the chances of successful weed seed germination within the newly added soil are reduced.

So, how much slope?

A good slope to aim for when grading land extending out from a house foundation is about six inches for the first 10 feet (that’s a slope of 5 percent). For details on how to determine this slope, click here!

Once you determine your needs, you should spread well-draining soil with a crumbly texture to sprinkle on the low areas. Work your way down the grade and then return to your first low area and carefully spread the soil out using a rake, so that the grass blades have an even one-half inch layer of earth across the entire low area. You should be able to see all the grass blades above the newly added soil. Spread the soil on each low area using the rake until you complete all of your filling. Wait six weeks to repeat the filling process if your lawn’s grade still requires alteration. This time period allows the grass to grow and acclimate to the first soil layer.

Now, what about that sump pump?

It is important to keep the discharge point of your sump pump as far from your foundation as possible. The minimum distance should be 10 feet. Most discharge pipes have a flexible hose tightly attached to the pipe coming from the basement. During non-freezing weather this works just fine.

Grab your umbrella and take a walk around your home during the next heavy rain. If you see pooling near the foundation, corrections are necessary. Correcting the slope (as recommended above) is going to give this water a place to go. In addition, make sure to periodically check your system during the winter months. A frozen sump pump will damage your home as when the water begins to thaw it has no place to go … except your basement or crawl space.

An added side note, many local water utilities are paying equal attention to sump pump issues. Lebanon Utilities recently launched a “No Flood Zone” campaign, reminding residents that sump pumps should NOT be connected to sanitary sewers – which creates an inflow issue for stormwater as well as increasing the risk of sewage back-ups in basements.

After making these corrections, if you are still experiencing a leaky basement, don’t hesitate to give us a call at 317.896.2885 or contact us at info@customconcrete.com.

Commercial Construction Broadens Footprint

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Meeting your Residential and Commercial Needs

From the time Custom Concrete poured its first foundation, the emphasis was largely residential work. From those roots, we’ve grown to be a well-known and trusted provider of residential concrete foundation work throughout Central Indiana.

That reputation and expertise in concrete lead us into a few small commercial projects that have ultimately become one of the fastest growing portions of our business.

In 2013, we completed a 715,000 sq. ft, concrete project for the Subaru Office/Distribution facility located in Lebanon, Ind. According to the Gordian Construction’s Senior Project Manager Craig Hetzer, the Custom Concrete commercial division wildly exceeded expectations. “Safety was a non-issue, all our milestone dates were met and the rather tight tolerance on slab flatness was exceeded,” he wrote to us after work was completed. “Instead of Custom Concrete being a risky hire, they turned out to be one of the strongest members of our construction team!” (You can read his entire letter here.)

Likewise, a 166,500 sq. ft. concrete project for Fastenal began Dec 13, 2013 and finished May 15, 2014, just seven days past the scheduled date (despite working through one of the worst winters in decades and losing 22 days to weather).

To see more of Custom Concrete’s commercial construction projects click here.

Increase Property Values

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The Benefits of a Basement

We all know that a good, well-built house begins with a good foundation. But what if you could gain some added value out of that foundation?

You can! It’s called a “basement.”

Yes, the basement … For some of us, the basement was the epicenter of our teen years; for others, it’s the designated home office space. For homes of high style and fashion, it’s where family and friends gather in the home theatre.

When I talk with future homeowners about building their house, the subject of a basement is often part of the conversation. And here’s what I advise: The basement is the most cost-effective addition of living space you can achieve.

Every house must have a foundation with which there is a minimum amount of associated cost. With a comparatively minimal additional investment (an average of $15 a square foot depending on basement layout, grade, etc.) you gain additional living space as well as a substantial increase in property value. An added perk: according to the U.S. Department of Energy, a well-insulated basement can gain the average homeowner between $200 and $400 a year in heating and cooling costs. Read more

Easy Fixes to Prevent Basement Dampness and Flooding

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Easy Fixes to Prevent Basement Dampness and Flooding

April showers might bring May flowers, but they can also bring on damp or flooding basements.

Every spring we receive a few calls from homeowners who are convinced that there’s an issue with their foundation … and almost always, that’s not the case.

Most damp or flooded basements are caused by things that are easily fixed … and even more easily prevented. Take a walk around your house and check out the following:

  • Downspouts – Clear them of leaves and other debris. If they are clogged, the water runs down the wall right into your basement. Likewise, downspouts should extend away from the house by several feet. Using the plastic “pleated” pipe you can find at any home improvement store is a great solution.
  • Make sure the grade of your lawn runs away from the house. Ideally, there should be at least 6 inches of slope within the first 10 feet away from the house. Also, it is very important to keep the grade at least 6 inches below the top of the wall or below the weep holes in the brick.  Elevating the grade (grass, mulch or hardscape) to high can cause water to run over the top of the foundation wall.
  • Sump pumps are one way to get rid of any extra moisture in your basement. Once installed, check periodically to ensure the pump fully functional and operating properly. Back up battery operated sump pumps are a great idea for those who experience frequent power outages – and remember, sump pumps should not be hooked into the sanitary sewer (allowing for sewer back ups in flooding conditions). Sump pumps should be installed to drain excess water into your yard or designated sub-surface drains.
  • During hot humid months, using a dehumidifier in the basement can reduce condensation on the walls, floors or any other cool smooth surface. This may work better after you’ve sealed air and duct leaks to reduce the amount of humid outdoor air you are bringing into the basement.

All of that said, our foundations are installed with an elaborate drainage and waterproofing system.  They are designed to prevent typical concrete shrinkage from leaking and to drain ground water.  By following these simple maintenance procedures, you significantly reduce your chance of dealing with a damp or wet basement.