concrete tank with checkered plate on top needs to be SEALED

[delagina]

i have a rectangular concrete tank with platform on top.
it needs to be air sealed so vapors dont escape, no pressure on the tank.

what type of seal do you recommend?

 

[delagina]

this is similar to a septic tank except top cover is made of checkered plate platform

 

[JedClampett]

Well, you could place some kind of concrete anchors around the top and put a compressible gasketing material between the plate and the concrete.
But if you're worried about odors escaping, trapping them might end up deteriorating the concrete and the plate.

 

[MiketheEngineer]

You might try the roofing product that is STICKY as all get out and is waterproof. Can't remember name of it!!

 

[delagina]

no, we are not trapping the vapors/odors.

we have pipe penetrations inside the platform. we even have manholes inside the checkered platform, but those will be welded to checkered plate - so those penetrations are sealed.

the edges though is my problem. steel to concrete sealant is what i'm looking for.

 

[TLHS]

You could either cast a groove for a gasket strip into the concrete or just cast the gasket strip in. However, if your plate is all welded up it may be difficult in the future to lift it up and repair the gasket if this is a long service life building. The other option would be some sort of epoxy or maybe a tar based sealant. You can inspect and repair that from the outside.

You have to make sure that whatever you pick doesn't react with whatever fumes you're sealing. So contact the manufacturer to see if they have tests with whatever you're dealing with.

 

[msquared48]

Do the plates have to be easily removable?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[dhengr]

Check with some local septic tank casters and see what they use for gasket material. I’ve also seen round rubber stock about 1" dia. which is either in a shallow cast groove and/or stuck to the top of the tank with some mastic. The problem you might have with your checker pl. lid is that it is more deflection prone, than a conc. lid, as it spans the tank or btwn. hold down (fastening) points. And, you want these deflections compressing the gasket further, not lifting the lid off the gasket at some points, at the corners for example. Imagine (calculate) how the checker pl. or its frame will deflect, and you do not want it contacting the inner edge of the conc. tank and lifting off the gasket. In similar fashion a few hold down bolts will compress the gasket at their location but may actually reduce gasket contact btwn. bolts, if the lid is not edge stiffened. Pay attention to how you detail these types of things: a stiff enough frame so its deflection isn’t an issue over the gaskets; or bolts outside the gasket at a hard surface (the checker pl. reaction line) so any pl. deflection further compresses the gaskets as the pl. deflects toward its mid span.

 

[StoneCold]

Here is a product that us used between concrete sections to make a water tight joint. It is called RU106 Rub-R-Nek by Henry. Maybe this would work for you.

Regards
StoneCold