Walls – How to attach pony wall to surface of platform and will it be strong enough against lateral forces


I have a loft area to which I want to add a pony wall for safety. My plan is to drywall its inside and outside faces, all the way down across the beam. Can I built it on the surface of the platform safely? I would prefer to avoid attaching the posts to the front of the beam because it would make drywalling more difficult, and I want to use the posts located at the corner as an anchor for some storage that should all appear flush. The beam is 5 1/8" wide so putting it inside the beam, against a joist, leaves too large a distance on the outside edge.

Here are some researched suggestions:

  • Built pony wall and lag-bolt the corner post through an angle bracket, down through the pony wall's bottom plate and into the beam.
  • Can I lag-bolt 4×4 posts to a 2×4 bottom plate from the bottom, which is then lag bolted through the subfloor and into the beam?
  • Extend plywood down the pony-wall onto the beam to provide strength across the entire face without adding too much thickness.
  • Use a thicker wall – perhaps cabinets – so there is more depth to anchor down.

Any other ideas?

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Best Answer

I'd build the wall in such a way that the entire thing acts as a post:

  • Use 3-1/2" or 4" construction screws instead of nails at all joints
  • Use construction adhesive at all joints
  • Use screws and adhesive to mount the bottom plate to the floor framing

This configuration will be as stiff and strong as it would be if you used occasional steel bracing. Any right angles or other wall connections will enhance strength.