Sometimes concrete ponds are constructed and virtually no thought is given to how the surface should be in regards to it being able to accept a waterproofing coating later.  Sometime the surface is either too smooth or too rough and needs to be corrected prior to applying the coating.

I have seen people use brick in the ponds also.  Now brick is a funny material.  It is either too porous or ultra smooth.  Porous brick is not usually an issue because the pore can be filled, but ultra smooth brick can cause future delaminating if it is not properly surfaced prior to coating.  The techniques to handle this type of brick would be the same as with concrete to be explained here.

I find that one of the easiest ways to make a smooth surface more rough is to sand blast it.  Of course sand blasting has its pros and cons.  For one thing, it most certainly will clean a surface pretty well and give a nice texture to accept a coating, but it also makes a serious mess.  You’ll end up with sand everywhere and it will be there until your surrounding yard assimilates that which couldn’t be cleaned up.

Also with sand blasting, you’ll have to hire someone to do it.  It’s not likely you own the equipment necessary and probably do not have the skills either.  That’s ok though, because there is at least one other way to accomplish this.

My favorite way is to use a large 8” angle grinder.  Suit up in protective eyewear and a face mask and you can go to town with a tool like this and either smooth out the concrete or rough it up as needed.  They work wonders.  Let me explain.

If you use a flexible sanding disc on an 8” angle grinder it allows you to cut away imperfections in the concrete while at the same time protects the concrete from you accidentally gouging to some degree.  This means you can float the grinder over the surface and follow the natural contours more closely without cutting away too much concrete.

You should use a 24 grit sanding disc for the process as it will leave a more desired surface afterwards.  Not to mention it will last longer since it is coarser.  Be sure to aim the spin of the grinder away from yourself.  There’s no sense in directing debris right at yourself.  It not only hinders your sight but the flying debris can injure you as well.

Take Gunite for instance.  Usually a Gunite installer will assume that you plan to apply a plaster coating to the new pool or pond and he or she will normally apply a broomed finish to the Gunite surface.  That’s fine and dandy for a plaster surface, but no good for applying a coating.  If you apply the coating to a surface like that, you’re likely to waste a bunch of material just trying to fill in-between the broomed gaps.

Finally, as I said before, this scenario works fine for smooth brick too.  If you can just give the brick a new surfacing, it will give the coating much more to grab hold of during the application process, which will give you a longer life with the coating.

Keep in mind that this process will also be helpful when smoothing out mortar joints too.  Sometimes masons can get a little slopping with their joints and there’s no reason to just coat over them as is.  Clean them up first.

*******************************

If you’re looking for a non toxic solution to water proofing your pond, fountain or water feature, please visit the Pond Armor site. If you have any questions regarding the products Pond Armor manufactures, please contact us at 800-716-1545 M-F 8:30am to 4:30pm PST

An ellipse?  What the heck is an ellipse?  Simple.  Ellipses are circles.  Ok, did that confuse you?  Think of ellipses as special instance of a circle, meaning if you have an oval shape, it’s still considered a circle, but a special case of a circle. 

If you have an oval shaped pond, you need to perform calculations for ellipses in order to figure out square footage and volume.  So, when we spoke about circles and some of your calculations were based off of the circle’s radius, it will be the same with an ellipse, but we’ll use the radius measurement just a little differently.

Major axis – The measurement that consists of the longest radius length from the center of the ellipse to the outer edge.

Minor axis -  The measurement that consists of the shortest radius length from the center of the ellipse to the outer edge.

Take a look at these pictures:

With an oval shaped ellipse, you’ll have two radius measurements.  One is longer and will be referred to as the major axis, while the other is shorter and will be referred to as the minor axis.  Remember when you calculated the area of a circle, you multiplied the radius by the radius and then by Pi?  This works the same. 

For an ellipse, you multiply the major axis by the minor axis and then by Pi.  So if the pond was a 20 feet long and 10 feet wide oval shape, you would calculate,
20 (major axis) x 10 (minor axis) x 3.14 (Pi) = 628

Don’t forget, you’ll have to measure the circumference (perimeter of the pond too in order to have the total square footage of the walls of the pond.  This is where it gets a little scary.  Because an oval is essentially a squashed circle, there are a lot of variables that would have to be taken into account in order to calculate the circumference.

First let me say that I will show you the varying calculations and you are free to follow along if math is your thing.  However, you may find that simply walking a tape measure around the perimeter of you pond is much easier.  Ok here we go for the mathematic enthusiast.

The first calculation you can do in order to find the circumference is an approximation only.  This means that you have to be sure that your major axis is no more than three times longer than the minor axis and your resulting calculation will be within 5% of being true.  That’s the approximation part.  Your calculation could be as much as 5% incorrect.  But hey, let’s look at it anyways.

You’re first going to multiply the major axis by itself and the minor axis by itself, and then add those two products together.  You then divide that answer by 2.  You take that total and divide it by the product of Pi multiplied by 2. 
20 (major axis) x 2 = 400
10 (minor axis) x 2 = 200
So now you have 600 /2 = 300
Now, 3.14 (Pi) x2 = 6.28
The divide 300 by 6.28
30 / 6.28 = 47.77 feet

Now again, I stress that this formula is an approximation and can be off, up to 5%.  So let’s just assume you wanted a formula that calculated the circumference of the oval shape almost exactly.  Well all I’m going to do is just show you the formula because it is nothing short of horrific!

Circumference = Pi(3.14) x (major axis + minor axis) / 4 x [ 3 x (1+L) + 1 / (1-L) ]
And that’s assuming L = h/4 = (major axis – minor axis) x 2 / [2 x (major axis + minor axis)] x 2
As well as assuming h = (major axis – minor axis) x 2 / (major axis + minor axis) x 2

Now do you see why I say it’s probably just easier to walk a tape measure around your pond?  There’s just no way I even care to calculate the circumference when it would take less time to physically measure it.  I certainly do not expect you to either.  So save yourself the time and headache and just tape measure the circumference.

Now that you have the circumference measurement, you need to multiply that by the height of the pond, like this (assuming the height or depth is 3 feet):
47.77 (circumference) x 3 (height) = 143.31 square feet

So the floor area square footage plus the wall square footage would be:
628 (floor area) + 143.31 (walls) = 771.31 total square feet

Again, to calculate how much Pond Shield epoxy you would need to coat this pond, you divide the total square footage by 60 square feet.  Remember 60 square feet is the amount of coverage a quart and a half kits gives you at a minimal thickness of 10 mils.
771.31 / 60 = 12.8 (rounded up to 13 total quart and a half kits)

To calculate volume of a oval (ellipse) shaped pond, you multiply Pi (3.14) by the major axis and multiply that by the minor axis and then multiply that by the height or depth and divide the total by 4.like this,
3.14 x 20 x 10 x 3 / 4 = 471 cubic feet

Then on to my obsession with water weight.  How much would that weigh?  3,956.4 pounds.  That’s quite a bit of water for a small elliptical shaped pond.  Oh, I almost forgot.  Not that we have talked about elliptical shaped ponds, remember Part 2’s question at the end?  Have you figured it out yet?

I’ll see you when we discuss triangular shaped ponds in part 4.

*******************************

If you’re looking for a non toxic solution to water proofing your pond, fountain or water feature, please visit the Pond Armor site. If you have any questions regarding the products Pond Armor manufactures, please contact us at 800-716-1545 M-F 8:30am to 4:30pm PST

Ok, here are moving on to rectangles.  FYI – all of these particular calculations will work for those of you with square ponds too.  As I said in part 1 of this series, you’re going to eventually need to know the total square footage of your pond as well as the volume.

The square footage will assist you in calculating how much of any construction material you’ll need to actually build the pond and the volume will allow you to calculate the needs of water that your pond holds.

Squares are pretty simple to calculate too.  Unlike circles, there are only three measurements you’ll need to take in order to get the information you need out of your calculations.  There is length, width and height.

• Length – This measurement is the longest extent of the pond, measured from end to end.
• Width – The measurement is the longest extent from side to side on the pond.
• Height – The measurement that is the longest extent from top to bottom of the pond.  You’d also refer to it as depth of the pond.

When we calculated the square footage of the walls of a circular pond, there was only one wall.  So keep this in mind when calculating the square footage of a rectangular pond.  It has four walls and all need to be accounted for.  Let’s assume that the length of the pond is 24 feet, the width is 14 feet and the depth is 4.5 feet.

To calculate the total square footage of the floor you would multiply the length by the width like this,
24 (length) x 14 (width) = 336

So the floor has 336 square feet.

For the walls, you would multiply the length by the height for each wall and then add them all together.  So,
24 (length) x 4.5 (height) x 2 (walls) = 216
14 (width) x 4.5 (height) x 2 (walls) = 126

So for this rectangular pond, you add the floor square footage to both wall square footage totals and you’ll end up with a total square footage for the entire pond.
336 (floor) + 216 (walls) + 126 (walls) = 678

Again, to calculate how much Pond Shield epoxy you would need to coat this pond, you divide the total square footage by 60 square feet.  Remember 60 square feet is the amount of coverage a quart and a half kits gives you at a minimal thickness of 10 mils.
678 / 60 = 11.3 (rounded up to 12 total quart and a half kits)

Now because we already know the length, width, and height, it will be very easy to calculate volume.  As a reminder, it is important to know the total volume of water your pond contains for purposes of water chemistry or how many fish you can safely house.  You know, that sort of thing.

To calculate volume of a rectangular shaped pond, you multiply the length by the width by the height of the pond like this,
24 (length) x 14 (width) x 4.5 (height) = 1512 cubic feet

Do you know how much all that water weighs?  12,700.8 pounds!  Yes, I make a big deal out of the total weight of the water.  I’ll tell you why.  If you are planning some sort of holding tank, something indoors, something on a pedestal of sort, weigh becomes a serious issue and you need to know what that will be in the end.

Next time we’ll talk about ellipse shaped ponds and how to calculate square footage and volume for those.  I’ll give you a hint.  They are similar in nature to a circular pond, but do you know what the difference is?  I’ll let you know in part 3.

*******************************

If you’re looking for a non toxic solution to water proofing your pond, fountain or water feature, please visit the Pond Armor site. If you have any questions regarding the products Pond Armor manufactures, please contact us at 800-716-1545 M-F 8:30am to 4:30pm PST