Re: Massive heaving on deck and patio in clay soil
Every winter the deck heaves in certain areas about 6" causing the upper patio door to pinch shut
Is this door on the exterior wall of the house or is this door part of a structure on the deck ?
Typically a raised deck would be attached to a ledger connected to the house framing. If the deck is heaving this area shouldn't be moving.
Two things come to mind ....
The deck posts are on 12" diameter sono tubes and 4 1/2' deep (which according to the city I live in is below frost depth).
1 ) are they indeed 4 1/2 feet deep ?
2 ) is they area where you live silty soil or possibly low lying with fill brought in for house building.?
The idea of the piers being the size and the depth they are to bear the weight of the deck structure as well to resist movement from frost heave. Depending on the soil conditions you may need a footing for the piers to sit on. The footings we use for these appilcations are those called " Big foot " which are wider at the base. The sono tubes are attached to them and when filled with concrete they become a monolythic component. The flared out portion of the " Bigfoot " provides the stability of dispersing the load but also helps to lock the pier down into the ground preventing heaves.
I wouldn't think your house is moving as much as 6 inches .... if it were here would plently of cracks visable inside the home that would indicate hat.
"" an ounce of perception -- a pound of obscure "