Concrete Pad for Listeroid 10/1

[mike90045]

Hello Mike,

Thanks for the good advice. When you speak of SS all-thread are you speaking of stainless steel threaded rod?
I have to anchor large air compressors from time to time and I typically use wedge anchors for this application. Do you find the wedge anchor inadequate?

I find the wedge anchors "uncertain".  Stainless Steel grades can be chosen for hardness/flexibility, McMasterCarr has a nice breakdown of what is what. My concern with expansion bolts or wedge anchors, is the localized pressure they put on the concrete, and if it starts to slip even a little bit, with a listeroid, it's going to end up somewhere else.   I used all-thread because it has lots of surface area to grip with.   
 So someone else may chime in and say their epoxy anchors let loose, and the wedge held fast.    Just a matter of opinion.

[Listerational]

Hello Mike,

Thanks for the good advice. When you speak of SS all-thread are you speaking of stainless steel threaded rod?
I have to anchor large air compressors from time to time and I typically use wedge anchors for this application. Do you find the wedge anchor inadequate?

I find the wedge anchors "uncertain".  Stainless Steel grades can be chosen for hardness/flexibility, McMasterCarr has a nice breakdown of what is what. My concern with expansion bolts or wedge anchors, is the localized pressure they put on the concrete, and if it starts to slip even a little bit, with a listeroid, it's going to end up somewhere else.   I used all-thread because it has lots of surface area to grip with.   
 So someone else may chime in and say their epoxy anchors let loose, and the wedge held fast.    Just a matter of opinion.

makes sense to me, thanks.


I have a basic idea of what I want to do with my 4" concrete garage floor. I hope that you don't mind if I run this by you for your opinion.
I would like to pour a 9.5" slab on top of a rubber horse trailer mat on top of the garage floor,
 and then put another rubber horse trailer mat on top of the 9" slab, and finally set the generator (with stand) on it.

I am hoping this will give me the necessary weight and maybe get a little resiliency from the 2 - rubber pads.

The garage floor has a grade to it. Not much but probably enough to make slab and generator travel down the grade. I do not know how to handle this problem since the slab will be isolated from the garage floor with a rubber pad. Should I just tie the garage floor to the slab by drilling half inch holes into the garage floor and sticking rebar into it with about 7" sticking out into the slab?

Thanks a whole lot for the help. I am just an electrician who is finding out that there is a science behind all of this.

Jim

[Tom]

If it were me, I would cut a hole in the 4" slab and then line it with the horse stall mats, then pour your concrete block in the lined hole. That way it will be captured and not transfer the thump's to the slab. In fact that is just about how I did mine, minus the rubber horse stall mats, and the engine still rattles the dishes in the cabinets in the house. Not bad but some dishes it does. Rental stores will have concrete saws that will do the job in an hour or 2 or you can buy a diamond blade for a skill saw and hope it really is a 4" slab and break out the pieces.

[mike90045]

If it were me, I would cut a hole in the 4" slab and then line it with the horse stall mats, then pour your concrete block in the lined hole. That way it will be captured and not transfer the thump's to the slab. In fact that is just about how I did mine, minus the rubber horse stall mats, and the engine still rattles the dishes in the cabinets in the house. Not bad but some dishes it does. Rental stores will have concrete saws that will do the job in an hour or 2 or you can buy a diamond blade for a skill saw and hope it really is a 4" slab and break out the pieces. 

I'd vote for that, because if the slab is tied to your house foundation/slab, EVERYONE inside will know when the engine is running, if they cant see the lights flicker. Line the hole in the slab with 4" high slices of stall mat, and then stall mat on top, between the metal frame and the concrete monolith.

[Listerational]

I like the cutting with saw idea and the lining the hole with stall mat idea. I will probably make a thicker slab though which is as easy as removing 10" of dirt from the hole. This will give me 10" + 4" + 3.5" = 17.5" in thickness of slab on a resilient earth base. I will add some rebar and maybe even drive in a ground rod and bond the rebar with the ground rod with the generator stand.

Thanks for the advice. I will let you know how it goes. Awesome ! ! !

[Tom]

Raising the whole engine off the floor about 12" really helps with cranking and working on it.

[Listerational]

Thanks for all of the help. A friend of mine is coming by today to cut the concrete for me.
Good point about raising it up Tom.

[Listerational]

This has been a good week building the concrete pad. I cut out a 55" x 30" section of flooring in the garage. I dug out a 9" hole inside the cutout, with a small layer of gravel and a vapor barrier. I lined the sides with 3/4" rubber padding, built a 7" form on top of the cutout for a total slab height of 16". Next I cut out a template with a 5/8" piece of OSB. Finally I cut 6  18" pieces of 1/2" stainless steel threaded rod and put nuts and washers on the bottom of them to act as concrete anchors.
Thanks for all of the help with this project.