Load-Bearing Wall Removal in Southeast Portland
Opening up a Southeast bungalow has a wrinkle that does not apply in most of the country: interior walls in a seismic region are not only carrying vertical load, they are part of how the house resists sideways movement. Removing one takes away both, and only the first is obvious.
In a small bungalow with a lot of glazing already, the interior partitions can represent a meaningful share of the total wall length available to resist lateral force. Take out a long one and the house may be adequately supported vertically while having materially less capacity to resist an earthquake than it did that morning — with nothing visible to indicate it.
So the design here has two outputs rather than one. A beam sized for the gravity load, and a replacement for the lateral capacity removed, usually as a braced or sheathed panel elsewhere or a moment frame if the opening has to be completely clear. Permit review in Portland looks at both.
What We Look At Here
- Whether the wall is bearing, and what combination of roof and floor load it carries
- The wall's contribution to lateral resistance, not just gravity support
- Beam sizing with deflection checked, and end bearing to an adequate footing
- Replacement lateral system: sheathed panel, braced frame or moment frame
- Whether the load path reaches a foundation capable of the concentrated load
- Interaction with any existing or planned seismic retrofit
More on the service itself: Load-Bearing Wall Removal. More on the area: Southeast Portland.
Questions
Frequently Asked Questions
Why does removing a wall in Portland need more than a beam?
Because interior walls contribute to how the house resists earthquake forces as well as holding up what is above. Removing one reduces lateral capacity invisibly, so the design has to replace it as well as carry the gravity load.