[NorthJersey]

I see all sorts of conflicting advice on pouring equipment pads. I want to make sure my AC condensers don't heave or sink. I see some recommendations for using clean crushed stone and others for 3/4" or other products. Some recommend layers. Does an industry best practice exist for the northeast? Might I end up creating a place for water to collect underneath my pad?

 

[Nealtw]

I see all sorts of conflicting advice on pouring equipment pads. I want to make sure my AC condensers don't heave or sink. I see some recommendations for using clean crushed stone and others for 3/4" or other products. Some recommend layers. Does an industry best practice exist for the northeast? Might I end up creating a place for water to collect underneath my pad?

How old is the house, it can make a difference. Less than 10 years the dirt around the house is still considered disturbed.

 

[NorthJersey]

The house is 70 years old, but the site for the three condenser pads is in a flower bed that I suspect may have been turned over a few times.

 

[de-nagorg]

Excavate down to undisturbed soil, or bedrock, whichever you find first, then fill with compacted crushed gravel in layers, 4 - 6 inches at a time, compact, and add gravel, compact, and repeat, until you get near the top, add an inch of sand, compact, add sand, compact, until you get a solid bed.

Frame your form, and pour the concrete, with embedded mounting bolts to mount your equipment to.

After it cures ( a week), bolt your equipment, and hook it up.


ED

 

[Nealtw]

The house is 70 years old, but the site for the three condenser pads is in a flower bed that I suspect may have been turned over a few times.

I would remove the top soil and anything organic and like Ed said compact gravel.

 

[NorthJersey]

Well, the job is done. I removed the topsoil, and I found some nice glacial till. I used a Bosch Brute with a small compaction plate to compact the soil. Two of the three holes compacted very little. The third hole compacted between six and ten inches. I added 3/4 gravel, placed the concrete, and I have confidence we won't see much movement. I used Laticrete Maximizer because it has air entrainment properties and high strength. You have to search around a little to find it in my area.

I'd never used a mixer before, but I found that the tiny mixer I rented was not much help. I spent a lot of time breaking up concrete in the mixer. The wheelbarrow seemed to go a lot faster and to provide a more consistent result.

Thanks for all the helpful input!

 

[de-nagorg]

Yep them "SMALL" mixers are near useless, you need to mis small batches in them to get it mixed well, as you found out.

But by the time you mix another batch, your first one is partly set-up, and might not adhere to it's new part.

That's why I own a larger one.


ED