To tar or not to tar???

[Ponderthis]

Well, got the hole half way dug and the frame for the shallow ledge that the border rocks will sit on almost completed. The liner will go over this ledge and with the border rocks sitting on it to allow me to have the water level about half way up the sides of the rocks. This will definitely make the appearance much more professional.

Now the question is, should I tar this pressure treated wood or leave it as is?

l'm only using this wood because I live in Florida and have very sandy ground. This should stop the tops of the sides from caving in once filled with water.

Anyone have a degree in pressure treated wood specialities that can give an opinion? As long as it lasts 10 years or more I'll be happy with it. Just don't know if tarring it will make the moisture in the wood begin to rot it sooner or if leaving the outside edges exposed to the ground will do this.

Thoughts?

 

[DrCase]

I like what your doing
I have rock below the water level around the rim also and it will make your edge look great
I dont know about the tar,,, but a little gravel just around the back side of the wood might help let every thing drain and dry out saving the wood

 

[Ponderthis]

Good idea Dr. I was also thinking I could wrap the liner around the back side and probably underneath of the wood as well in an attempt to shield the wood completely from the dirt (sand). May be difficult to do considering I'll have the rather heavy rocks on it at that point but may be doable.

 

[DrCase]

When you cut the liner to fit, use your scraps to add some extra protection under your rock ledge

 

[DrDave]

When you cut the liner to fit, use your scraps to add some extra protection under your rock ledge

Good point, most of the small scraps are not good for anything else.

 

[Ponderthis]

I actually still have a 15' x 20' liner that was used in this pond before I decided to redo it that will be used for my waterfall into the pond. I will only be using a small portion of this and can go ahead and cut what I need off of this and put it under the frame before I put the new liner in.

Great idea guys.

Thanks again for your help.

 

[Otter]

I'm pretty sure tar will make an EPDM liner swell.

 

[DrDave]

I would keep petroleum distillates away from the water.

 

[malatu]

I would also agree to keep the petroleum distillates aware from the epdm. If you wanted to adhere the epdm to the wood, you might want to contact a commercial roofer who installs epdm roofs. They have adhesive that is used to adhere epdm to roof decking.

 

[D&RW]

Good idea Dr. I was also thinking I could wrap the liner around the back side and probably underneath of the wood as well in an attempt to shield the wood completely from the dirt (sand). May be difficult to do considering I'll have the rather heavy rocks on it at that point but may be doable.

We live in the Willamette Valley of Oregon where it rains a lot. i recently built my wife above ground garden boxes out of untreated wood. I hit on the idea of wrapping them in painters plastic to prolong their life. What it actually did is capture the moisture and keep it in longer. I wouldn't try to wrap those boards with liner.

I think Dr. Case's idea is a good one. You could even enhance it a bit by using paver sand and a laser level to slope all the side fill away from the wood toward drainage. Lay in your paver sand make sure it slopes slightly the way you want it to and then fill in the rest with gravel. That should keep water from sitting next to the wood, at least.

 

[DrDave]

Urethane bonds EPDM to most anything. They use it to hold window glass in Hi-rise buildings. I used it to bond EPDM to boulders in my large waterfall.