Redwood Septic Tank Repair 1

[androsnich]

Hello,

I am repairing a 4' x 10' septic tank built with 2"x12" rough redwood.

I have some concerns about rotting, sealing the tank, and building an accessable cover.

All of the top two courses of of 2x12 are rotting; some of the bottom courses also. The floor is in good shape except as noted below. The cover is gone.

I have elected to build a second tank inside the old. I have heard this is a quick, viable alternative.


1) Is there a problem with rotting because the inner (new) tank will be contacting the old wood of the original tank - and not the soil?

2) Should I replace the floor also? If I do, the volume of the tank will be further reduced.

All four of the floor boards are physically sound. One has dropped about 3/4" at the effluent end, creating a potential leaking situation at the gap.

Is it possible to use a non-toxic sealant at the gap? If so what?

3) How do I build the top to keep the dirt and rain water out and allow for easy access? The typical method would be to place 10 - 2" x 12" x 4' across the tank and cover with dirt (3-4" in this case).

3a) Can I cover the top with visquine (plastic tarp) to keep the dirt and water out? or does this keep the moisture in and promote rot?

3b) Does anyone know of a method to build a top with an access or inspection hatch that can be easily opened without dirt dropping in. (Since the 2x12's span 4' it is hard to put a typical 20x20" opening hatch in the middle.)

4) Should I put a drain around the tank to direct rain water away?

Thanks for your help,
Harry

 

[dicksewerrat]

Why are you trying to save the redwood? Better check with the local inspectors. Put in a new concrete tank. You may not be able to repair the old one. You may not be licensed to do either the repair or new installation.