Load bearing walls - explanation

[kaspor]

Hello

I have two walls with floor joists running between them (refer attached diagram, walls 1 and 2).

One of the joists runs between the two walls (i.e. walls 1 and 2) and ontop of another wall (parallel to the joist, i.e. wall 3).

Diagram:

I've been assured by a structural engineer that the joists have been designed in such a way, that the parallel wall is not load bearing.

However, top plates of all 3 walls are at the same height, won't the joist bear some load on the wall running parallel and this would be considered a load bearing wall?

Just after an explanation to satisfy my own understanding

 

[phamENG]

It's semantics. From a design perspective - it's not load bearing. The floor would perform just fine without the wall below. From a reality perspective - that joist isn't doing anything and the load is in the wall.

If you remove the wall, the joist will deflect. Structurally, that's fine. Serviceability...depends on the load, how long its been there, and what kind of finishes are above. 9/10 times it doesn't matter. Every once in a while you'll get the odd crack that has to be fixed as the framing settles into its "new normal".

 

[Tomfh]

Yes the wall will be bearing a small amount of load, but if the joists have sufficient capacity then the walls contribution is unnecessary, i.e. "not load bearing". You can remove the wall and the joist will work fine.

Is there another wall or structure above the wall in this location? If there is, then it changes things a little.

 

[kaspor]

Thanks for the replies. There's an internal wall of a robe above it which is also not load bearing.

So in other words it wouldn't make much sense to be spending money on a joist above that wall, the wall can just be packed up to carry the upstairs load?

 

[Deker]

It absolutely makes sense to spend the extra $60 on a joist so that you or any future contractor / handyman / ambitious homeowner can remove or alter the wall in the future without the need for additional structural work.

Keep in mind that a load bearing wall will need a foundation if supported on grade or a beam beneath it if supported on a crawl space, so you don’t necessarily have the option of using that wall for “free”.

 

[phamENG]

The additional labor costs to build that one wall differently than the others would outweigh the cost of a single joist where I am. Keeping things simple and efficient is the key to savings - not oddball modifications to standard practices.