First of all I am going to assume that they are using removable cantilever coping forms on the pool. This type of coping will allow you to have a formed concrete look around the inside perimeter your pool rather than a one piece coping that would result in an aluminum inside edge to your concrete. So assuming that is in place they will then make sure that the ground around your pool where the concrete will be is free of sod (the top few inches including the grass) loose dirt and is down to virgin soil. This will prevent the concrete from settling. If there was loose dirt in the area where they are planning to pour concrete than they would most likely run into an issue where the concrete decking around the pool settles resulting in it ending up lower than you want it.
The concrete should also fall about 1/8″ per foot. That means that for every foot away from the inside edge of the pool they will want the top of the concrete to be 1/8″ lower than the top of the coping. So for example if on one side of the pool you want the concrete deck to be 4′ wide then the outside edge of the concrete should be 1/2″ lower than the top of the coping. The reason for this is to ensure that any rain water that lands on the deck will flow away from the pool rather than into it. You also want to keep in mind that they will pour the concrete at a minimum of 4″ thick all the way around the pool.
That being said they will also typically want to lay a layer of stone in the area where the concrete will be poured as a base for the concrete to sit on. So with that layer there they will need to make sure that they have 4″ available and still have the fall you need away from the pool. The easiest way to do this is to use a transit. If at this point the pool is still empty and without a liner, they may put the tripod for the transit in the shallow end of the pool, and set it so that it is just higher than the coping. This will enable them to use only one stick of the story pole rather than two. It doesn’t sound like a big deal but the longer that pole is the more difficult it is to keep it straight up and down.
Once they get all that set up they will probably use the coping measurement as a reference point. You might see them put the story pole on the top of the coping and adjust the eye so that they get a solid tone. This means that the eye is perfectly level with the laser on the tripod. Next you will see them adjust for the amount of concrete which is four inches. To do this they will move the eye up on the pole four inches. From there they can adjust for the fall. Keep in mind that up is down. So in an area of the decking that is four feet away from the inside edge of the pool they will move the eye 1/2″ up on the pole. The level of the ground including the layer of stone will give them a solid tone when setting the story pole on it. Doing it this way you will easily be able to determine the height of the stone in any given spot.
Next they will form up the concrete deck. There are a number of ways this is done. They may use either 2×4’s or forms specifically made for forming concrete. Once all of these are in place you will see them secure the forms in place and set the height using stakes and nails or screws. To set the height of the forms they will again use the top of the coping as a reference. This time however they will not compensate for the thickness of the concrete. Instead once they get the solid tone on the coping you will see them just adjust for the fall of the concrete at any given point and set the height of the forms at that point to give them a solid tone with the transit. Once they get it all formed up and set to height they will add rebar to give the concrete additional strength.
They could in fact do this before forming if they wanted, it doesn’t make difference. It is a good idea and in most places enforced to lay the rebar forming a grid type system creating squares about 2 feet by 2 feet while cutting off the excess that may stick out passed the forms. When they have the grid system in place they will start tying it all together using specific rebar ties and tiers. At this point they are ready to pour. Just before the concrete truck arrives it is a good idea for them to put oil on both the cantilever and concrete forms. This will make it easier to remove the forms and clean them later. Depending on how big of an area they are pouring it may require two concrete trucks to do the job. If this is the case they will determine where they want the cold joint.
There are special tools that are used when pouring concrete including a magnesium float, a steel trowel, and an edger. these all serve specific purposes that aid in making the concrete look nice. In addition to those tools you might see them using a bull
float and broom to get to areas that cannot be reached from the outside of the poured area and to give it a nice textured look when They are all said and done. Another handy tool to have is what we refer to as a concrete vibrator. This is used to help remove any air pockets in the concrete which is ideal for around the cantilever forms. Because these forms will be removed they will want to make sure that there are no voids in the concrete behind them. If any voids remain then you will definitely be able to see them when they remove the cantilever forms. When they have the concrete poured out they will go around the edges with the edger to give it a more rounded edge rather than a sharp angle. You will also see them go around with the magnesium float and smooth out the top of the concrete filling in any voids or really rough patches. At this time they will have someone using the bull float to get the center of the concrete area that cannot be reached with a regular float. When they are all finished with the floats it is time to move on to the steel trowel. This tool gives the concrete a really smooth finish and gets even the tiniest little voids out that they may have missed. When that is complete they will let it set up a little then go over it with the broom to give it a more textured look and feel.
They will let the concrete set up overnight and by the next day they should be able to remove the forms for cleaning. They will also want to saw the concrete into sections to control where it will crack.
When it is all sawed up you might see them pressure spraying it to remove left over dust from the cracks and surface. When doing this they are careful no to get to close to the surface. The pressure sprayer is powerful enough to remove the surface of the concrete if they get too close. When that is finished you are all set to enjoy your new deck.
I realize that there is a lot of technical mumbo jumbo in this post and that some people may do things a little differently but the point remains the same and you will end up with similar results. If there are any questions regarding this post please feel free to ask.
