How to make Sump Pit Covers 

I'm dealing with this right now, I had a 2x2' siliconed down on my uneven floor to cover. Because of the radon mitigation, sealing with silicone does seem to be the best route, even though it's a pain to rip back up. Some heat and my multitool with a metal scraper blade made it pretty easy to take up the old stuff. I'll do a cleaner install that will be easier to take up when the time comes but the point of this is it should be good for 10+ years until this pump needs replacement again. For reference, the pump in the that I am replacing with the same pump (M53) lasted over 15 years.

Nice Fix!!

Great tip! I was wondering why the plastic was melting on some cuts, and cutting cleanly on others.

Funny you mention that. I had a dual pump failure and my basement flooded. I had to pop off both covers. It required a screw driver but no big deal. The silicone was pulled off the cover either by hand or with a safety razor. Heres what I am doing differently this time. I Installed a water sensor in the sump pit that is tied into my alarm system. This notifies me if any water is collecting in the sump. Also, I tied a piece of string to each float and drilled a small hole in each cover for the string. This allows me to pull up on the string and test the float switches with the covers on and sealed.

That is an excellent point. If you do not have a perimeter drain, I would agree with you and say yes. In my case, I have perimeter drains that feed into the sump pits. The perimeter drains have corrugated Vinyl panels in-between the slab and the block wall to catch any condensation that may drip down the foundation wall. This doubles up as a vent point for the sump pumps.

@@OldSoulMillennial I'm looking into using InSoFast insulation/framing panels for my block walls which should be compatible with my drainage system (similar to yours). Once installed, it would (ideally) be air tight. In that case, if I installed a sump cover, is there some kind of checkvalve I could install in the lid to mitigate the vacuum effect? We tested radon levels when we moved in. They were at very low levels, but I want to be proactive. A ventilation system would be too costly as a currently unnecessary preventative measure. What would you suggest?

I don't have an open perimeter drain, as in a open gravel filled channel on the inside edges of basement walls, but instead, I have perforated PVC pipe inside gravel channel around inside perimeter that exit into sump pump pit. Both are graded toward the pit, so water runs down by gravity. Above that is a poured cement slab making a continuous basement floor. When radon system was installed, they drilled hole for 4" pvc pipe down into edge of concrete slab till it hit the gravel, then installed pvc through this hole and sealed to cement floor and upper part attaches to continuous running exhaust fan out through roof. Reason for the detail, is that in my case and others similarly done, there is no vacuum when sump runs, as it just temporarily overcomes the exhaust radon fan (aka it makes up the air need that way) by slightly reducing the fans output when the pump runs.

So before I took any action, my radon levels were around 4 pci/l . I did 3 things. I replaced my radon fan with a more powerful fan. It doubled the suction on my vacuum gauge. Second thing I did, was seal all cracks in the slab, and apply an epoxy floor coating. Third thing I did was install these covers. My radon levels now are between .5-.8 in the summer time, and around 1-1.2 in the winter time.

Outstanding! Thank you for following up with new readings.

@@OldSoulMillennial Just make sure that stronger suction power isn't so strong it prevents furnace fumes from venting out!

​@@TrevorFisher what do you mean by this? Just curious as i am about to do the same

No,but you can buy the 1/2 thick ones which would be okay

Yes I still use these covers. Every radon situation is different. These covers have definitely helped lower my radon levels. I have pull strings through the lids that allow me to test each sump pump float. If I ever need to access one, I would simply peel the cover off, scrape off the silicone and reapply.

@@OldSoulMillennialHave you had any issues with mold on the plexiglass? I installed one last week and white mold has already started, probably because of the humidity inside the basin and the light coming in through the plexiglass.

@@ZupE891 I have not had any mold issues on the glass. What side are you getting mold? The underside? If so, better underneath than on top.