Septic tank cover?

[milli...]

My septic tank has a ½? thick 3ftx3ft steel plate over the opening acting as a cover, and this is all buried 6? below grade. The tank opening is only 22?x22?. I just formed and poured my own 25?x25? cover of reinforced concrete, with embedded rebar handles on the top, and a 21?x21? lip on the bottom to sit inside the opening. Couple of questions:

1. I would rather not bury the cover under 6? of dirt again. It makes servicing it every 3 years a pain and super messy. But, I live in the northeast. Is freezing weather a concern? Then again, 6? of dirt doesn?t really insulate anything? the snow always melts above that location first. Is there any harm in just boxing out around the cover and putting a small deck made of Trex (or other non-rotting material) over it?
2. With me not wanting to bury the cover, and it being <10ft from the windows/door, I?m concerned about odors. When I place this new cover on the tank, should I put any sealant between the two surfaces? I was thinking some butyl sealant rope, but not sure if that would be so sticky as to make it difficult to pick up the cover in the future. Comments appreciated. Theodore

[Anonymous]

Re #2, I would try foam tape like this:

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Mine is above ground. Not sure if there is a second cover beneath it but there is no odor.

I have a second access to what was a buried switch box to my two drain fields. I had a second drain field put in when first came up. When second field started to get wet, I dug up the box and put a concrete ring to access above ground and there may be concessional odor. It is out back down hill and does not bother me or neighbors but if I were you I would seal but not glue with something too sticky.

If located where it is not unsightly, I would not worry about covering it.

When I got a new well a few years ago in the front yard code called for access to be a foot off the ground and I bought a decorative plastic rock cover.

I see they have the same type thing for septic covers:

[Clare Snyder]

Don't use butyl. Make a "gasket" out of closed cell foam - even Styrofoam PINK or blue foamboard works. Box out around the hole and make a "plug" to fill the hole - a simple waterproofed box full of insulation might work?? Or a solif styrofoam block like a dock floatation block?

[hubops]

My concrete septic tank sits only ~ 6 inches below lawn surface - it's never frozen in my 25 + years here in sw Ontario. If I were to create boxed areas for the two access holes - I'd probably use a couple layers of 3 inch rigid foam insulation then something strong & durable over that. I wouldn't worry about smell - that all goes up & out the roof vent. The factory-made concrete lids fit quite tightly and no seal or gasket is necessary - your home-made cover might. John T.

[gfretwell]

Couple of questions:

out around the cover and putting a small deck made of Trex (or other non-rotting material) over it?

cover in the future.

The septic pumpers here use spray foam on the cover and it pulls apart pretty easy. They scrape it down in the hole and pump it out with the rest of the trash people flush.