You need a new liner for your swimming pool but are told you'll have to "AB measure" your pool and now you're wondering how in the world you even do AB Measuring. Getting accurate measurements for a new liner is critical for the liner being made to correctly fit your pool so while this may not seem like a good time to learn a new skill, with our help and a little patience, you'll be AB Measuring like a pro (the first time around)!
Below are the important steps needed to AB measure your swimming pool for a new liner. The good news is that none of it is difficult, but it will take some time. Know that going in so you stay patient. Slow and steady wins this race, my friends.
To get scale and measurements correct, you need to establish two points for your AB line. An AB line is a straight line you mark on your deck about 4-5 feet out from the edge of your pool.
When facing your pool, point A must always be on the left of point B.
Point A and point B should be on a flat surface and the line, if it were to extend out, should not cross the pool at any point. See the example below.
Point A should be a minimum of 10 feet apart form point B however, a good rule to follow is the AB line should be about two-thirds the length of the pool. So for example, if your pool is 40 feet long, the distance between point A and point B should be roughly 26 feet.
Once you have the ideal AB line location, mark the line on your deck. We recommend a chalk line as this is more accurate than a hand-drawn line.
A chalk line is a tool that spools out chalk-covered string. The string is used to draw a straight line from point to point by using the tight line of string. Snap the string against your deck to create the line.
Measure the distance between point A and point B, as well as each point's distance to the pool. Notate these measurements in the proper fields on your measurement form.
Halfway between the A and B points, walk to the edge of your pool. This will be point location 1. Mark it as "1" with chalk on the inside edge of the pool. While you can either measure the distances from A & B to the this point now, we find that folks have an easier time with this process when they plot the entire pool first and then do your measurements.
From there, move clockwise, and mark a "2" approximately 2-3 feet away from point "1". The distance between points can vary and do not have to be exact. If you are marking points within a sharp curve or corner, your points will want to be closer to 1-2 feet. If you are marking points along a straight section you can make them further apart. Always make any corners or obvious bends a point.
Continue clockwise, marking the next number every 3 feet out. You want to use numbers instead of tick marks. You will need to reference numbers later down the line and will not want to have to count 70+ something tick marks to know which point you're referencing. Trust us, use numbers.
You can measure from A & B two different ways. Either use two different color tape measures (one fixed to each A & B stake) and measure from both A & B at the same time (just make sure you have an easy way to remember which color goes with each stake). If you go this route you'll want to pull both tape measures to point one on your pool's perimeter at the same time. You'll record the measurement you find from tape measure A (attached to the A Stake) in the A column on your measuring form and repeat for B.
If you only have one tap measure, you can measure from Stake A first and then go back to do B, as shown below. Secure the end to point A on your AB line and measure the distance to point #1. Note the distance in the "A" column on the chart provided within the form. Continue around the pool until you have recorded all your points with an "A" measurement.
Then secure your measuring tape to point B and repeat the process.
PRO TIP: Go back and spot check a couple of measurements again to make sure they are as accurate as possible.
Finally, take 3-4 diagonal measurements randomly from numbered points across the pool. This allows the cover manufacturer to have cross dimensions to reference. Note the numbers used and the distance between in the spaces provided on the form.
Once you have all your measurements, make your art teacher proud by creating a sketch of the pool, as close to scale as you can. A scale drawing means that the dimensions are the same but the size is smaller. For example, one-centimeter on your drawing might equal one-foot for the pool. Use graph paper for the best results. There's space provided on the liner replacement measurement form form for this.
You'll want to clearly show the locations of the hopper (Deepest part of your pool) and the break points for your slopes.
The AB line has to be in the same location on your drawing as it is physically with respect to your pool. Make your drawing match as much as you can.
Draw your pool's shape, the numbered marks, and the special features/obstructions into a scale-image drawing of your pool. DO NOT FORGET TO INCLUDE WHERE YOUR AB LINE IS AND IT'S DISTANCE FROM THE POOL. This will give us enough reference measurements to create the correct cutout for your pool cover.
It is very helpful to also have corresponding photos of your pool. This will help us how to translate your drawings into a real-world cover. Snap multiple photos of your pool from various angles with the AB stakes and chalk plot points still in place. If you have a balcony, second story, or even a drone (finally an excuse to use it), an overhead photo of the pool is also very useful.
Finally, collect all your measurements, notes, and drawings and fill out the custom pool cover measurement form entirely. Then send the form to support@royalswimmingpools.com along with your attached photos letting us know that you'd like a new liner. We'll take it from there! (if you have a preferred liner type, brand, style, pattern, etc. let us know in your email).
We hope that you've found this article helpful. If you have suggestions for how it can be improved or if you have a question, feel free to leave us a comment below.