Sandstone and preventing erosion

Hello all,

I'm in the process of building a pond in our courtyard and have a few
questions remaining even after reading all the pool of knowledge stored
in this group (bad pun, I know...)

Basically I need to know how well sandstone will hold up as the stone
used in a waterfall. The waterfall will be about 4 feet high with only
two or three 1 foot "free fall" drops onto basin shaped stones (mini
ponds if you will). The rest of the water will basically trickle down
the surface of the fall.

My concern is if the sandstone will erode and crumble from the water
action. I have a chunk of the stone soaking in a bucket and it is
maintaining its integity, but I can scrape it somewhat easily with a
fingernail. I know everything will erode eventually, but will the
sandstone turn to dust in weeks, months, years or decades?

Would it be prudent to apply a form of penetrating tile sealer to the
stone or would there be a better method ?(can't really change the stone
being used, sorry) I eventually will have plants/fish so toxicity is a
concern but I have plenty of time for all the nasties to leach out if
they ever do.

The pond is about 2000 gallons with an EPDM liner.

Thanks for any advice!
-Bruce

bruce wrote:

Basically I need to know how well sandstone will hold up as the stone
used in a waterfall.

Look at any number of ancient European churches. Sandstone is an often used
building material. It doesn't wear nearly as well as granite, but it
should last _years_ in a waterfall - assuming you aren't subject to
freeze/thaw cycles. If it freezes, the erosion will be greatly
accelerated.

--
derek

On 13 Sep 2006 12:29:27 -0700, "bruce" wrote:

Basically I need to know how well sandstone will hold up as the stone
used in a waterfall. The waterfall will be about 4 feet high with only
two or three 1 foot "free fall" drops onto basin shaped stones (mini
ponds if you will). The rest of the water will basically trickle down
the surface of the fall.

Not all the sandstone I have is the same, some pieces are harder than
others and I tried a sealer, but it was temporary.

I built a Tennessee sandstone water fall and it wasn't long (months)
before the water chose a path not of my design, so I built it again
thinking it would do better and last longer next time, since I had
some experience then. After 4 tries I finally gave up on the falls
and made a sluice out of PVC. (Ugly, but functional and positive, no
leaks.) I would choose a harder stone for my next waterfall, if I
could find the energy to build it.

I talked to one of the engineers about using their brand of retaining
wall stones for waterfalls and he guessed about a 10 year life, which
is much better than sandstone.

Regards,

Hal

Thanks guys!

The water will be shut off during winter so freeze/thaw shouldn't be an
issue.

I guess I'll just "go for it" and see what happens. Worse comes to
worse I could just create some water troughs out of copper sheeting to
channel most of the flow in the high erosion areas.

-Bruce

"bruce" wrote in message
oups.com...

I guess I'll just "go for it" and see what happens. Worse comes to
worse I could just create some water troughs out of copper sheeting to
channel most of the flow in the high erosion areas.
==================
Why not use a non-reactive material like rubber liner instead of copper?
Before I'm again trolled by "snooze," I was told to avoid using copper pipes
etc. where my fish and ponds are concerned.
--
KL....
Frugal ponding since 1995.
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
~~~~ }((((* ~~~ }{{{{(ö ~~~~ }((((({*

Köi-Lö wrote:
"bruce" wrote in message
oups.com...

I guess I'll just "go for it" and see what happens. Worse comes to
worse I could just create some water troughs out of copper sheeting to
channel most of the flow in the high erosion areas.
==================
Why not use a non-reactive material like rubber liner instead of copper?

Mainly appearence. A rubber covered waterfall wouldn't have the same
(ahem...) charm ;^)

Before I'm again trolled by "snooze," I was told to avoid using copper pipes
etc. where my fish and ponds are concerned.

Copper can cause issues when used in a closed environment like a fish
tank, but for my application I'm not very worried (though it is
something to consider).

The local water is very hard (alkaline) so leeching issues are
minimized, but some alternative
methods would be to use "harder" rocks where the water makes the
plunges.

Thanks for the input!
-Bruce



--
KL....
Frugal ponding since 1995.
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
~~~~ }((((* ~~~ }{{{{(ö ~~~~ }((((({*

On 14 Sep 2006 10:26:12 -0700, bruce wrote:

The local water is very hard (alkaline) so leeching issues are
minimized, but some alternative
methods would be to use "harder" rocks where the water makes the
plunges.

What about a sealant, like V8 or G4, for concrete painted on the rocks?

--
Regards - Rodney Pont
The from address exists but is mostly dumped,
please send any emails to the address below
e-mail ngpsm4 (at) infohitsystems (dot) ltd (dot) uk

"bruce" wrote in message
ps.com...

Köi-Lö wrote:
"bruce" wrote in message
oups.com...

I guess I'll just "go for it" and see what happens. Worse comes to
worse I could just create some water troughs out of copper sheeting to
channel most of the flow in the high erosion areas.
==================
Why not use a non-reactive material like rubber liner instead of copper?

Mainly appearence. A rubber covered waterfall wouldn't have the same
(ahem...) charm ;^)

Oh. My neighbor covered the liner with flat limestone rocks. You can
barely see it.

Before I'm again trolled by "snooze," I was told to avoid using copper
pipes
etc. where my fish and ponds are concerned.

Copper can cause issues when used in a closed environment like a fish
tank, but for my application I'm not very worried (though it is
something to consider).

It was my understanding if the water is alkaline the copper would not
dissolve and harm the fish or other aquatic life. Someone else I met at the
Pond club said that wasn't necessarily true. All you can do is give it a
go!

The local water is very hard (alkaline) so leeching issues are
minimized, but some alternative
methods would be to use "harder" rocks where the water makes the
plunges.

I see you read or heard the same thing. :-)

Thanks for the input!
-Bruce
--
KL....
Frugal ponding since 1995.
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
~~~~ }((((* ~~~ }{{{{(ö ~~~~ }((((({*

Köi-Lö wrote:

Mainly appearence. A rubber covered waterfall wouldn't have the same
(ahem...) charm ;^)

Oh. My neighbor covered the liner with flat limestone rocks. You can
barely see it.


I hope my liner will be fully hidden.

Basically I (will) have a stack of sandstone rocks with an EPDM liner
behind the stack to keep all the water contained and draining into the
lined pond. My concern is that the water pumped up to the top of the
rock stack will eventualy erode the rocks. It is my hope to build the
stack into what looks like an oozing spring, mainly just water flowing
down over the face of the rock stack. I do hope to have several ledges
built in that allow some water to pour over their lips and make small
falls that plunge into/onto flat sandstone rocks below. These lower
rocks will be slightly bowl shaped to form small pools so the plunging
water will not be directly in contact with the stone, but will be
splashing into the small pool formed by the stone. Either way there
will be water flowing over the sandstone and if the stone begins to
erode I thought about placing something at where the water flows over
the edge and where the water plunges into the stone bowl below to
reduce the erosion. I had though you were saying to place small sheets
of liner material where the water flows over the stones 8^)



It was my understanding if the water is alkaline the copper would not
dissolve and harm the fish or other aquatic life. Someone else I met at the
Pond club said that wasn't necessarily true. All you can do is give it a
go!

The local water is very hard (alkaline) so leeching issues are
minimized, but some alternative
methods would be to use "harder" rocks where the water makes the
plunges.

I see you read or heard the same thing. :-)


I can see a problem for copper that is submerged in the pond where it
is constantly exposed to the amonia and other products prouced in an
average fish pond, but in my application it would be acting more like a
gutter where it would get plenty of air exposure and get that brown
oxide covering. Of course if it begins to turn green and starts flaking
off I'll be in trouble....
-Bruce

Thanks for the input!
-Bruce
--
KL....
Frugal ponding since 1995.
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
~~~~ }((((* ~~~ }{{{{(ö ~~~~ }((((({*

"bruce" wrote in message
ups.com...

Either way there
will be water flowing over the sandstone and if the stone begins to
erode I thought about placing something at where the water flows over
the edge and where the water plunges into the stone bowl below to
reduce the erosion. I had though you were saying to place small sheets
of liner material where the water flows over the stones 8^)
================
I'm curious to know how it works. Report back on it if you remember.......
--
KL....
Frugal ponding since 1995.
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
~~~~ }((((* ~~~ }{{{{(ö ~~~~ }((((({*