Tension Tie Floor Connectors

Tension Ties or Horizontal Hold Downs are used in many seismic retrofits, especially in houses with stepped foundation, where  installing a plywood shear wall is not a good option.  This is usually due to  limited access or because the foundation steps on a very dangerous hillside home are so steep that plywood shear walls simply won’t work.  Here you can see the earthquake is trying to pull the house away from the foundation and down the hill.   This pulling action is transferred to the Horizontal Hold Down which in turn pulls on the foundation where the force is resisted.

Horizontal Hold Down Hillside

The other place they are used is when the house has an addition and we don’t want the addition to come apart at the corners.  In the image below the red arrow represents the earthquake pushing on the back of the addition.

Arrow Showing Earthquake Force Pushing on Back of Addition

If the corners of the addition are not securely attached to the main house the addition can be separated sometimes causing catastrophic damage.

This damage is prevented by connecting the floor joists of the addition to floor joists of the main house at each end with a special type of steel called a Tension Tie.

The blue arrow points to where a long threaded steel rod in the main house crawl space is going into the crawl space of the addition.  The green arrow points to at Tension Tie that is bolted to the joist on the main house side.  On the addition side it is connected to an identical piece of hardware installed in the exact same way.  This particular Tension Tie is being made with a Horizontal Hold Down, though this is only one of many methods use to achieve the same aim. The white arrow points to a nut that keeps the Horizontal Hold Down shown by the green arrow from moving


Below is a construction detail found in the 2007 International Residential Code pointing to the fact that scientists have come to understand how important this connection is.

Areas Served

San Jose,Sunnyvale, Fremont,Oakland,Berkeley
And Surrounding Areas


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License Info

Works' Comp RWCC64393236
Contractors Lic #558462
Bond #SC6334450
Liability Ins PCA 1045011
Link to Contractor's License Board