How do you apply poolcrete before measuring for a vinyl liner?

Answer 1

Working with PoolcretePoolcrete not be confused with pool-crete (pool plaster) is a extremely uncommon building material. Poolcrete is not a material that is stocked on the shelves of every Lowes and Home Depot. The only practical way to purchase poolcrete is from a swimming pool distributor of some type. As a thirty year veteran of swimming pool and water feature construction, poolcrete has been much of my lifes work. Poolcrete is a mysterious material to most who see it for the first time but in reality it is nothing more that vermiculite, cement, and a small portion of additives that tend to enhance workability. You can actually create a substitute for poolcrete by contacting a masonry based company that sells brick and block. The product that you should inquire about is typically known as "Zonolite" but any bagged form of vermiculite will work for you with good results if you get the fine grade. "Zonolite" is commonly used to insulate the cavities of precast block. Most times this material will come in four cubic foot bags. To make your on poolcrete mix 1- four cubic foot bag to 1/2 of a 90lb bag of type I portland cement (High Strength Masonry will also work) along with about 7-9 gallons of potable water in a paddle type gas powered mixer. Be sure to add most of the water in the mixer first followed by the half bag of cement. If desired you may add a couple of squirts of dishwashing liquid to the water and cement mixture to aid in troweling. DO NOT mix this material for more than four or five minutes as it will make it increasingly harder to deal with because it will become extremely tacky on your trowel. What you are looking for in the mixer is a material that does not completely cling to the paddles of the mixer as it turns. The mix should readily fall from the paddles but not to the point that it is almost like soup.

Enough about making your own poolcrete, now lets get down to business...

Mix your poolcrete in a gas powered masonry type mixture in the same method as discussed previously. Again, if you wish, you may add a few squirts of dishwashing liquid to the water content before adding the poolcrete. I would like to note that the use of the dishwashing liquid is a good practice for unskilled workers. Most professionals do not like to use it. Professional pool builders usually all have their own preferred method of appling the crete but what I am going to instruct you on here is the way we do it after 30 years of the practice. For this example I am going to set you up on a common 16 x 32 pool with 2' radius corners and a hopper depth of 8' that is a new construction. Most of the time we like to sugar coat the bottom of our pools with a couple of inches of crusher run from the stone company. This helps with having a neater workspace in the pool and also makes it easier to move to poolcrete around with a wheelbarrow. I am assuming that you have already installed any string lines that you will need on transitions that indicate where the finished surface should be. You should set up your mixer right at the edge of the pool wall in the shallow end and locate the poolcrete close to the mixer. We have fashioned a device out of 3/4" PVC pipe and a ball valve that connects to a common garden hose that hangs over and down into the mixer a few inches. This makes adding the water to the mixer more accurate and alot easier. You can make a 4' long shute from some scrape plywood and lumber screwed to the sides that can be wire tied to the bottom frame on the mixer. When you dump the poolcrete out of the mixer it will go down the shute and into a wheelbarrow. I have one worker that mixes the poolcrete and then gets into the pool and pushes the mix to where it is needed. Usually it is only me that is actually troweling the mix but sometimes I have one other troweling. As we build a high volume of pools, when I do the excavation I try and get it dug as fast as possible so the banks on the slope are usually over dug a bit. It is much faster to dig with a backhoe than with a pick. We always start on the banks at the transition from the shallow end and work the banks around the pool. When we are overdug (more than 2" of mix will have to be applied to the banks) we start with a roughin coat that will bring our mix to within a half inch or so of what the finish should be. The mixture for this should be fairly wet other than in places where gouges where taken out for rock or other things. If you have areas where it will take alot of poolcrete to fill in then go ahead and dump some mix into theses areas first and just bring them up a little at a time while you work on other areas. This roughin coat should be left "rough" so that the crete doesn't want to slide off the banks when you run the finish coat. Do not try to make this coat look good. The banks are what I think are the easiest to trowel but it is always the most time consuming part. Another good reason to use to roughin method is if you will not be able to complete the job that day for some reason like the possiblility of rain then you can go ahead and work on this because the banks a easy to cover with plastic. Poolcrete can be shaved of up till a couple of days later if necessary to get rid of a high spot. When you have the banks roughed in to maybe a half inch or so then you can run a finish coat. I like to run my finish on the wet side because it is only a half inch or so and it finishes better. When you are running any finished surface make your strokes as long as possible in a comfortable stance. Keep your body lose and just go with the flow and let your mind feel the trowel. While this is very much eye to hand coordination, you must remain in sync with the trowel and the material and let your senses take over. Troweling poolcrete is very similar to icing a cake. It is like Cool Whip mixed with peanut butter. What you are looking to acheve is a uniform surface. It is not supposed to be as slick as glass and you will have over troweled the material before you know it. Do not keep going over and over the mix as you would with conventional concrete. It is not concrete. You need only to slightly tilt the pool trowel maybe 1/16" of an inch to stroke in any direction. Make your pass good with the intention that the next pass will take out any trowel marks in the crete. If the first pass looks good then leave it alone or you may screw it up. The poolcrete should resemble gray asphalt and have a slight texture. It is common to work air into the mix during placement and this will cause bubbles to lump up on the surface. This is not that big of a deal so if you have this to happen just turn the trowel on edge and gouge the place to release the pocket of air. If you have to join wet poolcrete to a drier area then you can take a spray bottle filled with water and some dishwashing liquid and spray the drier edge first. This will help to blend the two areas together. The best method of appling poolcrete to the banks is to roll the wheelbarrow to the needed area and sling it on the banks with a square point shovel. Other areas can be dumped out and troweled down on spot. After we finish the banks then we usually bring the slope down and finish the bottom of the hopper. We leave a strip of the slope about 3' wide to come back up as we trowel this backward till we are back to the top (not so easy). At this point in time you are almost home free! Continue to trowel in the remaining shallow end and work toward the step as this is where you will exit.

I sincerly hope that this information will help some crazy sole that just really wants to do this for themself. I would also like to make a few other personal statements about this subject. I have built Swimming Pools for around thirty years and during this time I have often tried to train people to do this. I have only had one person that was ever able to trowel this material that met my approval and thank goodness this person is my wife and partner. If you do this and get results that please you then be satisfied... because most people just cant do it.

Thank you for reading this,Anthony Sloan / Sloan Construction Serviceshttp://www.sloanconstructionservices.com