Treated Wood Questions

[eddie209]

I am having some concerns on the wood for the bottom of my BOG. I was going to use pressure treated plywood 3/4" thick. It would be rested over the pond, sitting on a few 4x4's to give it a little height and more support. I am worried about the chemicals from the treated wood leach into the water. Either from spray, rain, or just from water changes.

If I were to go untreated wood, is there a safe sealer(stain) that is fish safe?

 

[poconojoe]

I don't know the answer to that, but I want to tag along to see what the "experts " will say.

They used to infuse PT lumber with arsenic, but from what I understand, that's no longer the case.

 

[Mmathis]

Will the treated wood actually be inside the bog, in contact with water, or will they be an exterior support and covered by liner?

 

[poconojoe]

Will the treated wood actually be inside the bog, in contact with water, or will they be an exterior support and covered by liner?

I think the intention is to build supports from PT lumber that will overhang the pond. The bog will be built on those supports. That's the way I understood it. So any rain, moisture or run-off from the PT lumber will end up in the pond.
So, is PT lumber dangerous to our ponds? I think I read they are copper infused, but that could be wrong. Years ago PT lumber was infused with arsenic, that's why it wasn't recommended around vegetable gardens. I believe they no longer use arsenic.

 

[Jhn]

Idk how much actually will each into the pond if any once the PT lumber drys out. Both of my ponds have PT lumber around them, the main 10000 gal ponds case its In the pond in the form of 6x6’s holding up a bridge. Been like that for 11 years now with no issues.... The other 1800 gal. pond is half raised out of the ground framed with 6x6’s that contact the water when it is full and run off it when it rains, this pond is going on 3-4 years old without issues. Just my experience, with it.

@poconojoe you are correct the PT lumber from the big box stores has copper in it still ( no arsenic though)along with some other stuff that is extremely corrosive to plain metal coated screws( the corrode away within a few years). This didn’t happen with the cca treated lumber.

All the lumber I used is still CCA (PT) lumber, CCA stands for chromated copper arsenic, this is what is on my pond. Except for 2”x material as no one can get that in cca anymore, unless it is govt work then it’s fine.

If you let the PT lumber dry out it should be fine, clean off all the residue. IDK about stains that are fish safe, but I wouldn’t trust any type of chemical liquid stain or sealer around a pond to be fish safe. Even if you stain it first and let it dry then build the bog, in a few years or less you will need to stain/seal it again, which will be impossible without spilling it into the pond. Also, big box store lumber is junk even the PT lumber if it is left exposed to the sun or gets wet consistently, touches the ground... I would build the entire bog Framing out of 4x or 6x material, so it will last as long as possible.

 

[eddie209]

Unfortunately I have already built the BOG. I agree about the Big Box stores wood being junk. Took me several hours just to find straight pieces. None of the wood will actually be in the water.
My trim is treated 2x6 boards. I am going to replace them with composite boards. The bottom (floor) of the BOG is a concern. I initially was going to go with treated plywood. Hand have the bog rest on 4x4s. Not I am thinking of several 1x6 boards. The 4x4xs will give the floor some support.


I found this sealer. It claims to be fish safe. I am still researching it.

 

[PondDIY]

Unfortunately I have already built the BOG. I agree about the Big Box stores wood being junk. Took me several hours just to find straight pieces. None of the wood will actually be in the water.
My trim is treated 2x6 boards. I am going to replace them with composite boards. The bottom (floor) of the BOG is a concern. I initially was going to go with treated plywood. Hand have the bog rest on 4x4s. Not I am thinking of several 1x6 boards. The 4x4xs will give the floor some support.


I found this sealer. It claims to be fish safe. I am still researching it.

Hello I know this is an old Post but how has your liner been? Any leaks developed?

 

[sissy]

most pressure treated wood is done with a salt that is safe . It would be really great to see what happened to th pond . Wonder why he never posted back . Is it because it failed or other reasons . I mean CALIFORNIA not fairing well with ll the taxes and crime and homelessness . Just look on youtube and watch the news and it says it all . Hertz and U haul here in VA just sent alot of moving trucks up to CALI. empty on trains because there were none for people to rent . It has been on the news here and in NC that people want to rent a moving truck but seems there are hardly any here . Only the tiny ones are left here .