How to support 1 corner of stair landing

Question

We have a stair landing that is approx. 4 feet wide and 2 1/2 feet long. The 4 foot wide side rests on the outside concrete block wall. One inner corner appears to be held up by a 2x8 and 2x4, nailed together going down approx. 5 feet to rest on the concrete basement floor.

The other inner corner is buried possibly into a chimney I'm going to remove. It does not transfer anything else above it, and must support the landing and top of the basement stairs.

For a 4 foot by 2 1/2 foot landing is a 2x8 and 2x4 nailed together sufficient to support 1 corner of the landing? I have searched several stair building books and they all gloss over this.

Answer 1

Yep, doing another pair of sticks under the landing where the chimney used to be is quite enough. Slip a galvanized plate under the existing & new leg to prevent moisture wicking. With your new sticks, anchor the first stick to the cinder block, even with just Molly or Mushroom Head Bolts before attaching the other stick.

This will avoid any possible future racking or pull-away type movements. Not that it would, but you can also avoid the anchors by doing an X-brace of sticks between the then 2 supporting legs or posts, so you don't make any holes in the walls.