Connecting a new concrete foundation to an old stone one?

[jeansa]

How would you go about connecting a new concrete foundation with an existing stone one. What is the best way to do this? I am worried that the connection will become a hinge/weak point where water will infiltrate. A local contractor has suggested bolting steel pins into the old foundation before pouring the new one to tie the two together. Does anybody know if this works or is wise?
Soukwan

 

[cdh61]

jeansa,

I assume the old foundation is on a strip footing given it is stone. The connection detail could be completed different ways, but you will still have the hinge/week point at the interface. The footings in the old and new may not move the same, and therefore you should expect differential movements. The bolting of steel pins is not a bad suggestion, but it would be best to considered covering the old and new with a uniform textile to direct water to the weeping tiles down along the wall. Therefore, if the old and new move independent of each other you can still have a small crack at the interface, but water will still be directed to the tiles rather than into the building.

regards

 

[Focht3]

Agreed.



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora. See faq158-922 for recommendations regarding the question, "How Do You Evaluate Fill Settlement Beneath Structures?"