This is a personal DIY project where I would like to take down completely some interior walls. I've done measurements all around, attic, crawlspace inside/outside, and openings as well.

The house is a rambler style 1956 build, gable roof, one story level simple as is. The roof has rafters.

The walls I like to remove are red colored on the 3D model, and marked on the drawing.

The model displays rafters, ceiling joists, posts/pier concrete positions, everything possible probably to know and judge if the walls are bearing or not.

All dimensions are ± 1.5 inches error and can be seen on the below image and also you can visualize the house as a 3D model on your browser to the following link:

http://www.valentinoprea.com/remodeling



What do you think?

 

Welcome to the forums.

Cool program !

It looks like the left wall in bedroom 3 IS load bearing.

 

What makes you to state that. Argument support?

 

That's a tough one. Your roof knee walls help resist rafter deflection when the roof is under snow load... and so how much they are assisting is pretty hard to calculate... no rafter sizes or spans, no ceiling joist sizes. And don't know your snow load.

One kneewall bottom plate (box beam?) breaks above the living room and the end is currently unsupported on one end... (that seems wrong) since all the other kneewall plate ends are supported by interior walls everywhere else. In that sense, the Lv Rm - Bed 3 wall is somewhat load bearing due to a second roof kneewall (box beam) terminating on it. The bedroom 3 closet wall has butt joints on the ceiling joists near it, and we can't tell exactly where the joint is, although they seem to be tied together well. If the joint is over the hallway wall I would think removing the front and side closet walls would not be a problem.

Removing the kitchen wall shouldn't be a problem assuming ceiling joists overlap directly over the 10.8 wall... but the bottom plate of your kneewall is not currently built as a box beam on that side... without the kitchen wall that deflection will be more pronounced on your ceiling joists. Whether any deflection there will be within tolerance is hard to know.

Rather than taking Joe Schmo's opinion on the internet, you would be better off getting the opinion of a qualified structural engineer who look at it in person and who can approve your alteration drawings for you. That's what they get paid for.

 

I agree the structural engineer is paid for this job, but since we are on DIY website let's talk and examine the problem.

Zone: Seattle area
Rafter size: 2 by 4's
Rafter span 2.2 ft
Ceiling joist: 2 by 6
Ceiling joist span: 1.3 ft

-> that is correct

-> that is correct too. The ceiling joists are but joint right over the closet door, meaning that in between the hallway wall and the closet door.

-> also correct despite that they overlap only 4 to 6 inches.

Now let's summarize this and getting things in place:
1. sistering the 5 ceiling joists that are but joint over the closet using 2 by 6 by 14 having 7ft on each side on each joist in order to remove the closet door and side
2. getting a 4 by 8 by 12 ft beam in order to open the wall between the living-room and bedroom 3
3. redo the work for supporting rafters over the kitchen making the box beam

Am I correct?

 

Looks like code for your snow load is a minimum of 25 psf.

and I don't think your spans are correct. LOL

Can't help you further anyway... but that all sounds about right.

You have sections of ceiling where your 2x6 ceiling joists span 26 feet or so unsupported. This is how my dad built, and like his, it is surely already sagging. The 2x4 roof as well.

 

Rafter span/ceiling joist span = I wanted to say that the distance in between center to center.