I've fought with my concrete pond for 10 years. I've tried everything:
hydraulic cement, waterproof concrete patches, epoxy paint, fiberglass. I'm
giving up and getting a liner.
Concrete ponds come with *many* problems. Here's a few:
1) You cannot find the holes & cracks. A very tiny hole will cause your
pond level to drop an inch every few days. Once there's water & algae &
bottom-gunk, you will not be able to find that tiny hole. I have tried
everything: dyetracers (they don't work in anything except crystal clear
water -- the murky grey of a watergarden obliviates the dye. Ultrasonic
leak detectors (small leaks don't make enough noise to detect). Hourly
level monitors (doesn't localize the hole, and completely fail when there's
multiple leaks -- as is common for concrete ponds).
2) Concrete ponds shift & crack. No matter how strong you make 'em (and
mine is made very strong), there's bound to be a little movement over the
years, as the earth settles, the temperature changes, roots grow underneath,
there's a frost heave, a minor earthquake, or the rebar/chickenwire rusts.
Even a slight movement will cause a crack. And then as your pond level
drops... Happened to me once when I was on vacation. Returned to a little
pool of slop and dead fish.
3) Concrete can't move. You cannot change the pond later on, to
accomodate your wishes 5 or 10 years later. When you sell your place, the
new owners might not like your water garden (for instance, they may have
young children and worry about drowning & liability). A shovel &
wheelbarrow will get rid of a liner-pond. Concrete wants a jackhammer and
backhoe.
4) There are lots of "concrete sealants" and "waterproof coatings" ...
none work very well. Most are sold for "not-below-waterline" use. All
require completely clean concrete in order to work. And you never really
know if you did a good patch job until you fill the pond and wait a week.
(Oh, the stories I can tell you about refilling a pond, putting the plants &
fish back in, only to watch the level drop...)
4) Any piercings will leak ... I advised my kids' school not to make a
concrete pond for the above 3 reasons, but they went ahead anyways. A ton
of rebar & chickenwire and seventy five sacks of concrete later, they have a
concrete pond that leaks. Amongst the leaking sites are where the fool
installed a bottom-drain. Turns out that plastic pipe has a different
coefficient of thermal expansion from concrete. So every time the
temperature changes, the school has to top off the pond ... about twenty
gallons a day.
5) Want to clean concrete to prepare it for patching? Use 30% hydrocloric
acid. You get a suffocating greenish gas, which really does a number on
nearby flora & fauna.
6) Concrete ponds are rarely designed for the actual loads they carry.
Contractors usually dig a hole, line it with rebar & suchnot, then slather
on concrete. But what are the stresses in the structure? Where will cracks
most likely occur? Concrete contractors are accustomed to small crack in a
house's foundation won't affect its structural integrity. But even a tiny
crack in a concrete pond will lose ten gallons a day.
7) Compared to lined ponds, concrete ponds are way more expensive to
install, expensive to maintain, and expensive to remove. Replacing a $250
poly liner is nothing compared to a week of fiberglassing the walls of a
pond.
Over the past 10 years, I've maintained (or help fix) three concrete
ponds. I advised a friend & a school against building concrete ponds, only
to watch go ahead and build their dream ponds. Sure 'nuff, the
friend/school came back to me, asking for aid in patching the leaks.
So my advise to anyone even thinking about a concrete pond: Don't.
-Cliff 14 May 2003
"Paul in Redland" wrote in message
...
Why not just put a liner in it? Future cracks would then be a non-issue.
Just my $0.02 worth
Paul
"Larry D. Gibbs" wrote in message
news:PEcwa.833099$L1.242015@sccrnsc02...
I have a Concrete pond that was here when I bought the house about ten
years
ago and the water level goes down rather fast. I see that who ever built
the
pond applied some sort of sealant on the bottom of the pond "off whitish
color" and the water seems to stay at that level. I have heard of G4
Sealant
but don't know where to buy it and how expensive it is. The pond is not
smooth, it looks like a rake and shoe imprint were used. What kind of
sealant can be used and also where can it be bought. I live in Tacoma
Washington. I had goldfish in it and they survived until the raccoons
got
them.
Thanks,
--
Larry D. Gibbs
http://www.larrygibbs.com/
Only left handed people are in their right mind.