[Stonehenge]

John -

I know I've mentioned this several times on the site over the last few years - there was a project in Miami that was a study in the use of geogrid. They were building a large paver area (tens of thousands of square feet) at a dock where shipping vessels were loaded and unloaded. Fantastic amounts of weight.

Specs called for crushed stone base of some crazy depth, like 3'. But for some reason (the reason evades me now - getting old), they had only 18" of vertical space they could excavate and replace with stone. So they needed a way to make that 18" as strong as 36" of traditional prep.

The solution? Layers of geogrid in the base. I used to have the article - if I find it I'll try to scan it and post it.

Geogrid: It's not just for retaining walls anymore.

As for the foundation tie-ins - I cannot believe that Wisconsin is the only part of the country where driveway, sidewalk and patio slabs are tied to the foundation. If it were, then every single concrete pad in a new const. home in the northern half of the US would have settled and cracked in the first three feet out from the foundation. Where the prefab concrete steps are sitting on a slab? Tied to the foundation. Driveway slabs? Tied to the foundation. Sidewalks? Same thing.

As for the added weight - how much weight do you think that foundation is holding up without those steps? How much do trusses, OSB, drywall, face brick and furniture weigh? 20 tons? 40 tons?

How is this different from a deck attached with a ledger board?

I hear you on wanting someone to sign off on liability, but this one seems like a no-brainer to me.

[Paul]

I have no problem with someone wanting a engineer signing off on doing something like tieing into a foundation. I was just explaining how it works and why it works. We have all seen old porches you know the ones that are all concrete say 5' high with lots of steps and about 12' wide, they are all over the Midwest. Sure some of them pulled off the poured braces connected to the foundation. But I have never seen one where the foundation was broken from the weight. They break away from the foundation by way of shearing the cantlever pour.

[johnkeegan]

I'll be the first to confess that my knowledge of the housing "trades" involves green things and walls and walking surfaces not attached to a house. But I do know that the weight bearing STRAIGHT down on an 8 foot tall foundation from the weight of trusses, drywall etc. is not the same as the SIDEWAYS force on the top of a wall. Think of one of those Karate guys breaking boards. Does he choose to hit the board from the side or from the top, down through the length of the board. Try it both ways and see where the real strength of the material is.

...And, it's strange but here in upstate NY I've never seen a walk or driveway tied into a houses' foundation. Maybe into the slab for a garage. Even the stoops are generally floating free from the actual full foundation. Why the difference in construction practices between here and Wisconsin? Don't know. Perhaps, subconsciously, this is why I seem averse to attaching tons of block to a foundation.

SIDENOTE: It's not often you get a chance to mix Karate and the subconscious into a landscaping discussion.