Hello, all! Oh, and I need info...

[Sheetmetalman]

No they arnt cemented in, and as I recall I had some form of support every 2 foot--mostly treated 2x4s but also some steel pipe--pipe was driven in to help hold the 2x6 from buckleing outward but looking back I dont think I needed it because I put a 2x6 cap board on top as a place to sit or place rock and that cap board wont allow the water weight to push out the 2x6 edge board--Look in water garden photography under Pond in Southern Illinois to see what I mean by a cap board. Also the waterfall side has all the dirt piled up in a sort of mini-mountain all the way across that side--the liner just climbs that hill and my waterfall support which is in the middle of this hill then the granite slabs were placed on top of this liner and the large rock was stacked on both sides of the waterfall on that liner and right up the hill--all 3 other sides were the wooden collar method I described in other post, Tim

 

[James5]

Checked out your pics and very cool. I may just go that route, especially since I can avoid a lot of cement work that, quite frankly, I stink at. The 2x6's and 2x4's you used, were they treated with anything special or just basic outdoor wood stain?

 

[Sheetmetalman]

I personally treated them with nothing----however they are treated before you buy them--just tell the lumber yard you want "treated" lumber (for outdoor use)--they will know what you need. Eventually I will stain that top 2x6 for looks, but havnt got around to it yet--if you decide to stain your treated wood they recommend to wait 6 weeks to allow them tro dry out and weather slightly.

 

[James5]

Ok, decided to go that route. Spent part of the day today measuring out where the 2x4's are going in at. I'm guessing you filled the pond prior to "sandwhiching" in the liner? Otherwise I imagine you could up with tug issues?

 

[Waterbug]

My 2 cents...The stakes can still heave even if extended slightly below frost line. A single wood stake as a lot of surface area, the soil and ice around it will bind and lift the stake because it's so light compared to the surface area in contact with ground. You see the problem when you try and pull a stake out of the ground...the only thing holding it in place is the soil in contact with the sides. If that soil moved so would the stake. Concrete on the other hand is really heavy, the grip soil and ice has on the sides of the concrete is generally not enough to move the concrete. That's why we're only worried about frost underneath pushing up. It's the only way ice can get enough leverage.

You can overcome this problem by driving the stake way below the frost line. The not frozen ground binds to the wood and holds it down. But we could be talking 5-6' deep.

This is why most codes don't allow treated wood foundations.

Pressure treated wood is only rot resistant, not rot proof. It comes in different levels of protection rated by the amount of chemical put into the wood. The stuff sold at the big box stores I'd assume the minimum treatment. Wood varies too. One piece might rot in a couple of years while another could last 10-20 years. But having a single stake rot may not be a problem. A 4x4 stake will last longer than a 2x4.

Use hot-dip galvanized or stainless steel fasteners. Steel could rust and fail before the wood.

When pressure treated wood is cut the cuts have to be treated with a chemical specifically for this. Without proper treatment the life of the wood is much shorter.

You can't pile a ton of rocks on the top of these. The wood cap Tim has is light. Rocks would drive the stakes further into the ground.

Pond really needs sloped sides. With straight sides, and these boards close to the edge, there wouldn't be enough earth to hold the stakes.

Erosion of the top I think could still be an issue.

 

[Sheetmetalman]

I see your point on several things Waterbug--but I can only go with my expierences of what Ive seen thru the first full year of my pond. I worried about frost heave but saw zero evidence of it this winter ( it was a milder winter--but we did have some periods of extreme cold--only other colder winters and time will tell) To your point of different grades of Treated Lumber, James should be all right if he tells them what its for--they will give him Ground Contact Treated Lumber--(although on this point I'm not sure I quite agree with you-most of the new treated wood formulations are much better than they used to be)--however 1 thing that I did fail to mention James is these newer Formulations are so Tough that they will eat the regular steel and even galvanized steel fasteners(screws and nails) up quickly---you have to use triple coated or stainless fasteners-again they will know at the Lumber Yard just tell them what your doing. Waterbug is correct that 4x4s will last much longer than 2x4s and support more weight but in my application I didnt need them--if you plan on stacking lots of layers of rock on top of the cap board by all means go that route--you may want to even upgrade your edge board to a 2x8 or 2x10 but I didnt need it to be that heavy duty on mine. One thing I should have Clarified was WHERE to put your stake-like Waterbug says if you have steep sloping sides and a deep pond as I do you wouldnt want to have the stakes dug in next to your ponds hole--no support--I have a 10'x 10' by 5 1/2' deep main hole but then it stairsteps back for a plant shelf then stairsteps back to ground level for an 8" deep shallow plant shelf so my stakes are around 4' back from the main hole so I have plenty of support in dirt that is no where near the deep hole. Good Discussions like this can only make your planning stage better James before you start sinking a bunch of Time and money into your project. I agree with a lot of what Waterbug says but I also Temper my reasonings on pond building with the fact were not building the Taj Mahal or the Great Pyramid of Cheops here, LOL--we want it to last as long as possible and be as maintenance free as possible for the money and time involved. But by its very nature of wooden supports and rubber liner the best you can probably hope for given the method I decsribe above is 20 to 30 years--Now if you want it to last MUCH longer and have MUCH more MONEY, LOL--thats a different story. Good Luck, Tim

 

[Sheetmetalman]

sorry its early in the morning --stakes are 2 foot plus back from the edge of deep hole not 4'--and yes James dont pin the liner till you fill the pond and have everything were you want it.

 

[Waterbug]

I worried about frost heave but saw zero evidence of it this winter

I grew up in Upstate NY and the ground would freeze to better than 3' (I built pole barns which required drilling holes in the ground, 3' of frozen ground, fun). I agree with you, it was pretty rare to actually see heave damage. We had lots of sidewalks and there wasn't a huge amount of heave damage. Cracking sure, but not like the sidewalks all had to be replaced every year.

For most pond designs I would not worry much about freeze heave damage. The only places are like what you said, heavy stuff. Placing a ton+ rock on the edge of a pond...yeah, that requires a real foundation.

To me, for most cases, a simple reinforced concrete collar is plenty good enough for up to say 80-100 lb rocks on top. There will be some heaving and the collar will crack, but it's no big deal. The reinforcement will hold the chunks together. Unless there's something strange, like setting a collar on loam or mulch, then heaving could become a problem.

I think it just has to be scaled to the pond and what the owner is willing to accept.

To your point of different grades of Treated Lumber, James should be all right if he tells them what its for--they will give him Ground Contact Treated Lumber--(although on this point I'm not sure I quite agree with you-most of the new treated wood formulations are much better than they used to be)

Pressure treated wood is graded 2 basic ways. The first is normal lumber grading, #1, #2, etc. A lower grade wood is more likely to split (check) which exposes untreated wood to rot.

The chemical treatment is graded by the number of pounds of treatment per cubic foot of wood, pcf. So this grade could be say 0.15 to 0.60 pcf which would be a marine grade.

I agree with a lot of what Waterbug says but I also Temper my reasonings on pond building with the fact were not building the Taj Mahal or the Great Pyramid of Cheops here

Absolutely. Generally when I discuss building I try to stay in with standard building practices. I'm not saying a person must follow those, but I think it's smart to know the standard methods so when you chose to deviate you're making an informed choice. For example, knowing why pressure treated wood isn't allowed for foundations is better than thinking pressure treated wood will last forever, or that it doesn't rot. Choices are good, surprises are bad.

I'll relate this little story about wood vs concrete for what it's worth...I'm a wood guy born and raised. I never learn mason skills growing up, few people around me did. When I built my first above ground pond I went with pressure treated wood. Thought it would be easy and cheap. A couple of ponds later, wanting to learn different methods, I bit the bullet and built an above ground pond with concrete block. What I learned there caused a 180 in my material of choice for ponds. I'm now concrete all the way. Just saying I was surprised how easy, cheap, strong and long lasting concrete was. I wish I'd tried it decades earlier.