Tips for Success
Preparation FAQs Placing Orders On-the-job Product Safety Quality Control
Concrete has been a basic building element since Egyptian times which makes it difficult to think where we would be without it. Every major construction project uses concrete in one form or another because of its superior lifespan. It keeps us safe and warm, allows us to get to work safely, and adds beauty to our homes and yards.
Concrete is produced from some of the world's most abundant resources and without toxic byproducts. This environmentally friendly, inert material can be recycled and reclaimed throughout its manufacturing process. Its thermal mass and ability to reflect light play a role in energy efficiency by keeping our urban areas cooler, which in turn, conserves energy. From the homeowner to the largest urban areas, concrete is playing a major role in protecting and maintaining our environment
Preparation Tips - DIY & Contractor FAQs
How do I build the forms?
Walks, patios, shed bases, and similar flat work are usually formed with
2x4s set on edge and nailed to stakes placed about four feet apart. Set forms so that finished work will have a slight slope for drainage.
How thick should the concrete be?
Ordinary sidewalks, patios etc. should be 4” thick. The recommended thickness for driveways is 6”.
Is it necessary to put a sub-base under the concrete?
No, unless the soil drains poorly or is soft or mucky. If this is the case, place
4” – 6” of sand, gravel, or crushed stone in the prepared area.
What mix do I use?
It depends on the job. The most popular mix is a 4000 psi, which should be used on any project exposed to freeze/thaw conditions.
What is the proper procedure for placing concrete?
Place the concrete in the forms to the full depth, spading along the sides to ensure complete filling. Strike off the concrete with the length of a 2x4 in a saw-like motion. Repeat this method twice to remove any bumps.
Low spots should be filled before the second pass to provide a uniform surface.
Immediately after striking off, work a Magnesium Float, a.k.a., “mag float” back and forth across the slab to smooth it and remove irregularities. Work a slight amount of cement paste to the surface. Don't overwork concrete as it will result in a less durable surface.
Where do I use expansion joints?
At all points where the new concrete abuts curbs or other fixed objects. Expansion joints should be of 1/2” thick molded strips extending the full depth of the slab. Walks should be divided into sections about 4’ long, by cutting a 3/8” groove with a trowel.
How long do I wait before finishing the concrete?
Rough Texture With Float Marks: The rough texture produced by the mag float can be your final finish. The appearance can be improved by using the wood hand float in a swirl pattern. This is done after the concrete has begun to stiffen. Get out on the slab by walking and kneeling on pieces of wide, flat board laid on the surface of the concrete. Work the hand float in wide, sweeping arcs across the slab and back off the slab as you work.
Rough Texture Without Float Marks: If you prefer a roughened texture without float marks, draw a fiber brush across the surface. The concrete should be hard enough to retain the grooves or mark made by the brush. The roughness of the brushing can be varied by using a stiff broom or a very soft brush.
Smooth Surface: If you desire a very smooth surface, the final finishing is done with a steel trowel. Delay steel toweling until the concrete is quite stiff, otherwise excessive water will be worked to the surface. Too much water on the surface would weaken the slab. Work the trowel in sweeping arcs in the same manner as mag floating. For the final finish, use the steel trowel again when the concrete is almost hard. The trowel should make a ringing noise as it is worked over the slab and little or no mortar should cling to the trowel in this final operation.
What about curing concrete?
Concrete must be cured so that it will be strong and have a durable surface. Curing can be done by keeping the concrete continuously wet for at least three days in warm weather and 7 days in cool weather. This can be done in a number of ways.
When the concrete is hard, moisten with a hose and cover with a plastic sheet weighted down around the edges. This will prevent rapid evaporation of the moisture. You can also cure by keeping the slab wet with a sprinkler or by covering the slab with wet burlap or other material making sure to keep the material burlap moist by occasionally spraying with water.
How do I know the amount of concrete to order?
Concrete is sold by the cubic yard. It is not necessary to know the exact amount. Our concrete calculator will do it for you. Click here
Placing Orders
- Place your order as far in advance as possible (minimum 24 hours). The more lead time you allow our dispatchers, the better we will be able to handle your needs. Communicate with our dispatchers to give them an idea of what you’re planning for the week. Last minute orders and “I’ll call you later with details” type of phone calls only lead to mistakes.
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Will call orders are fine but must be released at least two hours in advance.
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If there is a change in your order, please contact our office no less than one hour before your scheduled delivery time as we need to calculate for truck loading times and travel.
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If you know your labor is going to be late or the jobsite is not ready at the requested delivery time, call dispatch immediately so they may adjust the schedule accordingly. No one wants to worry about concrete trucks sitting on the job site for too long.
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Cancel orders as soon as you know you can’t pour.
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Order at least 10% more concrete then your calculation. This will allow for batching tolerances, spreading forms, uneven sub grade, settlement of sub-base, residual materials in mixer, spilling, etc. Also remember that it could get costly if we have to send an additional mixer to deliver what could have been delivered in one.
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Make sure directions are correct. Street names and addresses are vital. The more information we have to direct our mixer drivers saves time and ultimately money.
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If you’re not sure the mixer truck will be able to maneuver or fit on the jobsite, request for a salesman to come out prior to delivery.
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Be sure to order what you are actually going to need. Ordering 10+ or even 200+ is fine. However, we account for one more load with every “+”. For example, if you order 10+, we allow for 2 trucks. Each additional “+” after your original order effects our ability to fill your order in a timely fashion.
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If you have a job that is different than your normal type of work, let the dispatcher know so they can adjust your mix accordingly.
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Be honest in your dealings with our dispatchers. Let them know of potential slowdowns that may affect the anticipated return time of the mixer. Remember this will affect our ability to service another order. With proper communication, we can assure in the future the rolls aren’t reversed.
- Remember to take into account about 20 minutes for a mixer to prep before leaving the plant and any travel time to the job site.
On-the-job Communication & Safety
- Make sure you are ready to pour prior to the mixer arriving at the scheduled delivery time. Not being ready when the first truck arrives will affect our ability to service your remaining loads.
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If you request the mixer leave the road and onto your jobsite property, you must sign the delivery slip taking responsibility for all damage that could occur to both our truck and any property on the jobsite. If you unsure about the site, the builder should be there!
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Help guide the truck onto your jobsite. Know what is under ground and overhead. Watch for wires, tree branches, mail boxes, etc. Our trucks are heavy, tall, and wide.
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When guiding a mixer, only one person should be giving directions or instructions to the driver.
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We do not carry any extra chutes, but carry the maximum the manufacturer suggests.
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If you add additional chutes, you are responsible for bracing them and any damage to existing chutes.
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A mixer truck has blind spots so be very careful working around the truck.
- Never walk or work under a mixer’s chutes.
Product Safety
Freshly mixed concrete, mortar, grout and cement slurry are irritating and corrosive to the eyes and skin and may cause irritation including alkaline burning and dermatitis. Avoid contact with the skin by wearing suitable clothing and gloves (clothing recommended gives full cover but minimizes perspiration, i.e., cotton overalls or long sleeve shirts and trousers, gloves, face shields or goggles and dust mask). In the event of contact, wash skin immediately with clean water to minimize possible irritation. If any material gets into the eyes, avoid rubbing, wash immediately and repeatedly with clean water or eyewash solution. If irritation persists, seek medical attention.
Do not breathe cement dust or the dust created from cutting or abrading hardened concrete, mortar, grout or slurry as it contains various quantities of crystalline silica which could irritate the respiratory system and may cause bronchitis, silicosis or lung cancer (Quartz or crystalline silica has been classified by the International Agency for Research on Cancer IARC as Group 2A, a probably human carcinogen RTECS 1989). When cutting or abrading hardened concrete and mortar, keep it wet to avoid creation of dust.
Wash clothes regularly and separately from other clothes.
Quality Control
- Know what slump you want to pour. There is standard equipment and a standard test to determine slump. If you’re unsure of which slump is needed for your pour, please contact our quality control department for assistance.
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Do not add water for slumps above 6 inches. If you need to place concrete at higher (looser) slumps, you should do so with mid or high-range water reducers such as Super-P. Pouring at high slumps creates segregation of the mix (stones piling-up and cream flowing away).
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Adding one gallon of water to one cubic yard of concrete will:
- Increase slump by one inch
- Decrease strength 200-300 psi
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Increase shrinkage potential by 10%
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Do not finish concrete until all the bleed water has disappeared from the surface. Weather is very influential on concrete’s ability to be ready to finish. When there is low humidity, winds, direct sunlight, high temperatures or worse a combination of the above, the concrete may appear to be ready to finish even though only the surface has dried out. On days like this you must protect the drying surface with the use of a vapor retarder.
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Never sprinkle water on to the surface of drying concrete during finishing.
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Do not steel trowel air-entrained exterior concrete.
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Always use 4000 psi concrete where it will be exposed to freezing and thawing conditions. This is the minimum recommendation by ACI.
- Cut joints in slabs as square as possible and not more than 2½ feet apart for every one inch of thickness.