Septic Tank Cover Repair

[ETpilot]

Well, last Thursday Mr. Murphy got me. I, for some reason, parked my truck in a location where I never park my truck. Just behind and besides my shop. It was a good day so I planned to mow the grass. I first needed to move the truck into the back pasture. Well, my trouble began. Instead of backing up and driving along the normal path, I drove straight ahead right over the septic tank.

My front right wheel went into a hole. At first I did not think septic tank instead a sink hole. I got the jacks out and a few boards and jacked the truck so I could drive it off. Once the truck was moved, only then did I see that it was the septic tank. I knew they were in the area but always thought they were closer to the shop.

Next day I spent my time digging out the tank cover. Since the cover had been pushed down, a dirt bridge had been left over the opening. I had to somehow hold that dirt to keep it from falling into the tank. The solution was a couple of ramp boards counter balanced with railroad track and my hand cart. These RR pieces had some weight to them. The plan worked. I managed to dig out the dirt with minimal dirt falling into the tank.

 

[ETpilot]

As you can see in the picture the cover was badly cracked. This cover was an odd size and I could not find anything locally that would fit. All fiberglass covers were either too large or too small. I considered a 5 concrete cover but when I looked at it in person I did not really like the idea. So I decided to repair the cover that I had. I purchased some fiberglass supplies for the project.

So here is where I am at. I pushed out a couple of dents in the cover. Then I worked the cracked pieces back into position as best I could. I fiberglassed some heavy mat to both the bottom and the top side. This made the cove really solid again. But, I am not sure as to how strong it is now. A friend suggested I put some metal reinforcing strips over the repaired cracks and fiberglass that in too. Not sure if this is overkill or not. I am hoping I can cut the grass with my Kubota Zero Turn mower. It weighs right at 1700 pounds. The cover will be under 18-24 of dirt. What do you think? Strong enough as is or reinforce with metal? Now that the cover is out I plan to add risers so cleaning will be easier.

On the second tank, it looks like the cover has taken a concave shape into the tank. Once I finish this cover I will inspect the other cover and fix if needed.

Any comments or suggestions on this repair will be appreciated.

 

[CurlyDave]

I would be very uncomfortable driving a mower over a repaired septic tank cover. That 1700 lbs. is empty and without a driver.

What don't you like about a concrete cover? Especially if you could get some specifications on it.

If you know where the cover is, you can lift it with your FEL -- weight is not an issue.

24" of dirt will add close to 300 lbs/sq ft of load to the cover. It looks to be about 18" in diameter, which I make out as 530 lbs. just from 24" of dirt. Add 500 lbs from one wheel of your mower, and you are asking that cover to support 1000+ lbs.

Do you really think it is up to that?

Take a look at a man hole cover. This is the type of thing you need to support traffic.

The plastic covers will take a man standing on them (although I make it a practice to walk around the cover and not stand on it) and maybe a few inches of dirt. For deep burial, rings are added to the tank opening to elevate the cover and reduce the amount of dirt on it.

 

[Domush]

If you do decide to keep that cover, you will need at least two more layers of glass on the inside of that repair. Each layer should overlap the previous by two inches or more. I have a youtube video which shows how to make that kind of repair. It is meant for repairing boat hulls, but is the same for any repair.

Www.youtube.com/lowkeelt

As long as you scuff the area to be repaired, the final product will be as strong as the original, if not more so. Glassing is an art, so do some youtube watching before you dive in.

 

[radioman]

After you put the cover back on and put at least a foot of dirt on top, you need to build some sort of underground bridge over that manhole if you are not planning to open it again or build in a way so its easily accessible. Even a simple wood blocks on the sides of tank and couple of pressure treated 2X12's on top of blocks will work wonders for spreading weight. Then bury the rest of it and forget it about it.:thumbsup:

 

[biggerten]

Construct a fake wishing well, windmill or some such. This will keep anyone from driving over it again, and aid you in finding them when you need to have them serviced.

 

[schmism]

i would use the fiberglass cover as a pour in place form. Use a heavy grid of reinforcement wire and pour a 2-3" concrete "lid" on top of that plastic cover.

h3ll id make a cover out of 2 layers of pressure treated 2x8 nailed/glued and cut to the circle before i trusted that fiberglass cover again.

 

[GGB]

What is the diameter of this cover? It wasn't clear to me, but I'm not a fan of the idea of driving over a lid, regardless of material or size after my experience.

Last spring I had to replace our septic tank lift pump, and in the process I had to dig out the solids tank lid to have it pumped out. It was buried under about a foot of dirt. I replaced the concrete lid with a riser and plastic lid, and also replaced the plastic lid and riser on the liquids tank which had been cracked by someone (including me-guilty as charged!) driving on it. Since I don't like the idea of digging any more than I have to, I installed the new risers about 6" out of the ground to make it easier to access as necessary down the road. Then I used hardwood mulch to cover the lids and risers. My Bride had wanted an island there anyway, so we added some ornamental grasses and flowers to fancy it up. Now I just mow around the island and stay off the lids and tanks.

It will be a lot easier to pump out in the future-just shove the mulch to the side and unscrew the lids. Also, I don't have to worry about breaking the lids or worse yet the tanks because I'm not driving over them with mowers or vehicles.

I guess I just don't understand why the lids for septic systems would be buried in the first place, especially with a lift system like ours that will require pump replacement on occasion. It's pretty easy to disguise them.

GGB

 

[ETpilot]

Thanks for all the comments. This cover has a 51" diameter. The clean out holes are 9" diameter. Mowing over the tanks would be a nice to do but not really necessary. I have been mowing over them all these years and they have held up until the truck incident.

I am going to add more reinforcement and put it back in service and see how it holds. I will also add risers for any future clean out. With the 2 clean out openings I have access to the tank baffles. The concrete cover only has a center opening for clean out only. Acesss to the baffles would not be possible without raising the cover. The dirt cover is just an estimate as I did not measure the depth.

This cover was not well made. The thickness of the fiberglass changes in areas. From 3/16" to almost 1/2".

Domush thanks for the video link. I have worked fiberglass before but I do not use it often. I will give thought to the other suggestions.

I will see how this works out. Thanks again all.