may be some one will give you a post ,but i would stay with the 45 mil pond liner.that is what it is made for.you are going to spend a lot of money to build a pond that big dont screw around on the main part

hi Joe

thanks for your comment, actually, what my nieghbor proposed is much cheaper than EPDM 45 mm liner. Yes sir, that is why I am here asking the pro before break the bank!

I have never heard of GAF-TPO. Looked at a few websites and they certainly use it the same way EPDM is used on Roofing....but I am not sure how flexible it is. EPDM could be 100 ml thick and still be flexible. It is also puncture proof to a great degree.

Can't say GAF TPO is not a good material but know that EPDM is.

HI Mike,

thanks for your input. my nieghbor is expert roofer who have been in business for 25 years. He said EPDM is nolonger used in comercail flat roof instead they use the GAF-TPO. he said, the later one can be welded using robot and not matter what shape or size you want, it can be custmized. I am not expert in the matrials nor in pond building, but I think (based on touching the (GAF-TIP) I felt it will be problem when used in pond that have many curves and steps due to its thickness.

GAF-TPO come as 10x 100 or 8 x 100 and can be easily make it 100x 100 as one piece using the robot! the roll cost about $500, therefore, based on my calculation I need 3 to 4 rolls to do 50 by 30 ft pond. EPDM will cost over $4000. again, I never seen or touch EPDM or bill board canvas to see the diffrent.

Is this safe for fish? The 45mm from Firestone, I think, is safe for fish and plants. I installed that last year.

Also, think about how this pond is going to fit In your life in the near future and even 5 years.

Large ponds are alot of work for at least the first year or until established.

Equipment costs, water treatments costs and maintenance (could be significant) are all important, expensive, time consuming factors.

Are you planning on staying in this house for years?

Home Depot carries a small pond liner if you want to go touch and feel.

Also does the robot seaming last a long time. I wonder what happens if you need a repair to a seam? Tree roots, heaving rocks and tunneling critters can damage a liner.

That liner will be hard to work with just in sheer size and weight. You will need practically a crew. It will be hard to make it conform to steps and the overlap for the edge. There will be bulky folds. You will need really big rocks for the edges to hold it up. How deep? Any waterfall? Excavation? You also need to consider padding. That could be a bed of leveling sand.

We opened our liner and let it sit in the sun to ake it more pliable and then of course it was so hot to handle. Ahhhh, sweet memories!

Do you really want to start this big?

EPDM is the kind of rubber inner tubes are made of, if ever rode one of those in water. In fact, I would guess the the thickness of an inner tube is probably a little less than 45 mils. what is nice about EPDM is that it "gives" and bounces back. I sat in on a pond building workshop at a home and garden show several years ago and the guy said that EPDM ponds he built in the country survived having cows walk into them and not puncture....that is strong! Also, EPDM is less likely to puncture.

Hello Meyerk9

Thanks
for your well said concerns. I am thinking of these concerns every day!
I live on 3.5 acres. 1.7 acres is cleared and still in the planning
phase. Small pond will not look good in this huge lot. Therefore, I
like to have larger pond to give the space some look and not put too much of
SOD! The Excavation expert in the
area will dig the pond for $1500 only, he have done many pond here.

You brought a good point whether this GAF-TPO
safe for the fish, and the bulkiness of it. I think I will stick
with EPDM martial or use the Canvas PVC instead.

I will go to HomeDepo and check out the liner
there as you suggested.

Yeah the project will be costly, but I am
sure it will worth the cost.

is the padding and leveling use sand of
something else?

thanks

Mike,

In
term of Puncture, the GAF-TPO is much stronger, yet I think it is not flexible
as mentioned by meyerk9.

One of my neighbors
who made half acre pond used Canvas:

https://billboardtarps.com/custom-large-sizes/

He have for five years
now and no problem at all. This is cheap, fish friendly and reliable.
I am not sure if anybody have experience with it.

http://www.pond.com/calculator.

I was driving after posting all that I thought about "attractive nuisance".

One has to be careful these days.

I have read about homeowners getting into a tiff with their local govt over ponds. Some had problems with potential runoff from the pond. You might want to ask around about that. Or you could subscribe to the " it's easier to beg forgiveness than ask permission".

Your excavator will see the soil composition and then you can decide about padding. I think I would put it down because of the weight and volume of water. I put down 3 inches plus a layer of felt. Some don't add any. You can imagine how frustrating finding a slow leak would be. You will have to deal with evaporation issues. Where is the water to fill the pond coming from? Hopefully it's close by for water changes and top off.

If its a well, have you tested the water?

Using the above tool, 40X50 and I allowed for 3 feet deep is around 44 thousand gallons. I think you may be able to stock it with Bass and have a tournament, lol

The depth number will affect the width and length.

As far as the extra dirt goes. If you completely dig out the pond then at times you could have flooding if there were heavy rains or runoff.

Or use some of the extra dirt to build the bog. Bogs are a wonderful way to clean your water naturally. I had a nitrite issue. 2 water iris fixed it. Highly recommended!!

If you dig it out part way then you can use the dirt to build up the sides so the whole pond is slightly raised and protected from water running into the pond during a storm.

Also, it's more visible so harder for some one or something to inadvertently fall into. This may not be an issue if your property is fenced.

My husband is also a roofer and we used TPO. Like mentioned above it is bulky but the welding can curve it to your desired fit. I love my pond. I currently have two baby koi testing out its "fish safety" can report back when i know if they make it. So far in my experience its cheaper and does a great job. Holds plant life well and ph and other levels are good. Ill let you know fish results.

Fish have made it the first 24hrs perfectly. I see no problems arrising. Just your normal watch on leveks and temp.

Tpo seams are welded together check the seam thoroughly and you will never have a problem