How to lay a perfect concrete floor in your home
Concrete is the most versatile of all construction materials. A process called hydration makes concrete plastic and pliable when newly mixed, strong and durable when hardened. Because of these characteristics, concrete can be used for building bridges, skyscrapers, dams, highways, pavements, swimming pools, houses and the backyard barbeque pit.
Concrete is essentially a mixture of paste and aggregates. The paste composed of water and Portland cement coats both the fine and coarse aggregates. Through hydration the paste hardens and achieves strength and hardness like rock. The key factor in having a strong and durable concrete lies in correct proportioning and mixing.
Generally a concrete mix is about 10 to 15 percent cement, 15 to 20 percent water and 60 to 75 percent aggregate. Sand and gravel are the fine and coarse aggregates and its proportion in the mix also determines the strength of a concrete batch. Typically, the more cement a concrete mix has the more durable, hard and smooth the concrete will be.
Laying a concrete floor is major construction. Big areas that need to be cemented are prep big time before the pouring of the concrete. For big areas that need to be cemented, ready-mixed concrete from batching plants are preferred because this type of concrete is precise. An even and better quality of concrete is produced all through the construction. For the most part, hand mixed concrete would suffice for a floor area that is less than 1 cubic meter. In case you plan on pouring concrete in an area that is greater than 1 cubic meter, you can easily rent a cement mixer and do your concrete pouring in batches of 1 cubic meter per.
It is easy enough to lay a concrete floor. If the floor area is rather large and you think batching the work will not do you good either, go hire a professional to do the job for you. There is no use doing a job that you are not qualified to do in order to save some money. You might double or even triple the cost of your concrete floor due to your inexperience.
However, if you have the aptitude to do basic masonry and carpentry, you can actually lay a concrete floor without much hassle. The steps are simple enough. You just need to have the right tools and "attitude".
Prepare the Concrete Floor Site
Make sure that you have precisely measured the area to be concreted. Prepare the ground by making the soil compact. Rent a jumping jack for ease in the process. If the soil is too soft you might need an official soil test to determine the relative compaction by a qualified professional. See to it that the soil is evenly tampered. You can tell this is so by the smooth and level line of the ground. To achieve an evenly compacted ground, make sure you move the jumping jack slowly square foot by square foot until the soil is firm and smooth looking. Do not minimize this work as this is the core of a "crack-less" flooring.
Lay the Base Course
The next step is for you lay the recommended amount of gravel. This base course is usually two to four inches in depth. The base course's depth depends on the kind of soil you have and the type of structure you will put up. After the gravel, put down the necessary amount of sand. Two inches of it will do. If you want you can also lay down a vapour barrier to prevent damp course. If you choose to waterproof, a 6 -mil polyethylene plastic sheet is highly recommended.
Putting Reinforcement Bars
If you are doing the flooring of an area that has light load, then concrete flooring without rebars might do. However, for your own good and safety better lay out standard reinforcement bars on the floor. Big structures are required to have their structural components computed by qualified structural firms. However, for your house, a standard #10 rebars spaced at 600 mm both ways will suffice. This reinforcement is good for slabs on fill. For second floors (and up), a different kind of design for reinforcement is called for.
If you are going to use ready-mixed concrete make sure the perimeter is established and that interior screeds or flat boards are already in place. A 2"x4" interior screed will do. Don't forget to prop the rebars with dobies.
Pour the Concrete
You can do these two ways: use ready-mix concrete or use hand mixed or mixer mixed concrete. Whichever one you choose, make sure the concrete is still pliable when you pour the concrete mix. Ready-mixed concrete has to be used two hours after it has left the batching plant. On the other hand, hand mixed or a batch mixed by a mixer has not guarantee of a precise mix. Each type of concrete has its pros and cons and only you can say which one will work best for you.
If you are using ready-mix, you might need an extra pump truck to deliver the concrete to the area. A concrete pump hose is not easy to handle. It takes a lot or practice to be able to operate one. Your best bet is to have the ready-mixed concrete fill a wheel borrow and for you to dump the concrete into the construction area. Start from a corner and slowly spread the concrete into the rest of the area.
Make sure the concrete poured and raked are even out. Two people can use the screed to move it back and forth (much like a saw) to push the concrete. Bull float the concrete after you "screed" it. Wait for the concrete's moisture to rise up the surface then evaporate before you final float.
Wait at least 10 days for the concrete to cure. Keep the new concrete wet and cool to prevent heat from prematurely cracking the surface.
"great article , its got all the elements you need, don't forget concrete is a great medium to work with but its hard to remove if you get it wrong... so get yourself a good jack-hammer"