Help with new pole barn floor

[orangeracer]

This is my first post I'm getting ready to start on my 40x64 pole barn located in north central Iowa. The building will have 6" of concrete and be heated using a forced air furnace.

I have access to some crushed asphalt at a decent price so is that alright to use under my slab or should i stick with gravel or sand?

My next question is about the insulation around the perimeter of the slab i've done quit a bit of research and have found where people have went straight down a few feet with the foam board, go straight down and then in under the slab a couple feet, or go down then out away from the building a few feet. Will all of these designs work and is there any advanages or disadvantages to one or the other?

Thanks

 

[rburke65]

Welcome to GJ...To help answer your questions, it would be helpful to know where you are geographically. Why would you want to go through the cost and labor to insulate living in Florida or where ever. At least a state or country helps. And yes all insulation is good if you have the bucks.

 

[orangeracer]

The building is going to be in Webster City, Iowa witch is in the north central part of the state.

 

[oilslick]

I used asphalt grindings for some of mine and wet compacted it, it felt really solid when finished, everyone who helped pour the floor commented on it.

 

[oilslick]

I also did 2" foam vertically all round except the doors, I was unable to keep it in place there! I was just trying to keep it from heaving since I hope to only heat my 32x54 when I need it, though I may decide to keep it at 50 degrees, hell I don't even have a furnace plan yet! I only went down 24" since that worked out with 4x8 sheets, they are damn pricey. A tip, go easy putting fill or backfill on outside of the foam it's tough but still easy to buckle it when using a bobcat to place fill. I believe the right way is to install horizontal as well as vertical and go below frost but I am not looking for perfection just figure some is way better than none.