Tuesday, January 31, 2012

Some Progress in the Basement

Well, I lied...not all the demo was done.....

I forgot to have this wall to the mechanical room removed.

Now you see it, now you don't.

New Wall.
I've never built a load-bearing 2by6 wall before...
And officially I still haven't as the wall shown below does not have a 'real' footing underneath it. Its just sitting on the 4" thick slab.
There was no room to tilt up the wall so I built it in a way no real carpenter would. Besides, working alone how would I tilt up a 21' 2by6 wall?

How Not to Build a Wall
First, I laid out the bottom plate and made sure it was parallel to the center load bearing wall. I tacked it in place with the ramset.
Then using two 'cabinet jacks' I stuck the top plate roughly in place. Then I used a 'straight' 2by6 and a level to make sure it was exactly in line with the bottom plate. Then I shot the first top plate to the underside of the joists, up from below. Then I nailed the second top plate to the first.
Then I measured and cut each stud separately and nailed them in place.

I also built my first triple 2by8 header. The span table said I could get away with only a double 2by8 header (and two jack studs to span 3-2) but then how would I make up the rest of the space in the 2by6 wall?
So, I used three 2by8's (good for a span of 3-11) and two sheets of 1/2" ply. I used construction adhesive to glue all the pieces together then I nailed the heck out of it with the nail gun. Its a very heavy, solid piece.
If you notice the header is nailed directly to the double top plate...there is just enough room for the door underneath it, as long as I don't get too crazy with the shims.
Putting that bugger in place was a comedy of errors...trying to lug it up there while getting the cabinet jacks underneath it...I picked that thing up, hefted it into place at least 8 times before I got it right....

Its a good thing building the header went well as I have a sinking feeling that there are no code compliant headers over the two doorways in the 'official' load bearing wall...

After I built the wall I swear the floor above feels a ton stiffer.

Built this little wall

To fill in the open area where the kitchen was.

The doorway from the mechanical room into the other kitchen was also filled in and I mounted the units electrical sub-panel in the opening.
I also mounted most of the new electrical boxes in the walls, ceilings.
I will not keep most of the existing electrical it seems...at least the existing in the kitchen has to go...I'm hoping to re-purpose the stuff in the other rooms.

Had some important visits last week.

First up, my building inspector.
I wanted him to come out and take a look at the situation since we uncovered a lot of 'hidden conditions'. He was like, 'Ya, gotta fix all those buried junction boxes.'
He also pointed out a couple of code violations that I had missed.
Its against code for copper water pipes to touch galv gas pipes...didn't know that.
He also said that there needs to be fire stopping between the top of the furring wall and the actual exterior wall. He said that stuffing the hole with Fiberglas insulation would be okay. I also plan on filling all the joist and stud bays completely with Fiberglas insulation....so hopefully belt and suspenders fire stop wise.

The BI also did confirm that the HVAC soffits are not built correctly...

The soffit needs to be uh, enclosed on the inside completely with fire code sheet rock...
So, hurray, more demo, as I will have to yank the existing soffits down and put up the drywall then rebuild it...

Actually, I'm not sure how to do the soffit. I've been puzzling over the HVAC plans and how to implement them in the 'real world'. Right now it seems like I have more HVAC trunk line than I have space for it...
However it works I will make the soffit big enough to conceal the trunk line, plus any number of utilities like the gas lines, the main water lines, electrical, TV-phone lines...If I'm lucky I won't have to drill thru hardly any joists! Course I have to build the fricken thing....

I was also happy about what the BI said about the floor joists. You see, floor joists have specific code specified lengths they are allowed to span. Depending on the type and grade of the wood and its size.
The BI confirmed that they are Douglas Fir and that he would be very comfortable with using the #1 column in the span tables!!! That's really good cause #1 wood spans a lot farther than #3 or #2.
I couldn't get him to agree to let me use the Select Structural (the strongest modern wood grade) column. He said I would have to get a structural engineer for that.

Visit From My Structural Engineer
The next day my engineer could make it out to look over the situation. I wanted him to take a look at three places where I was not sure if I needed to add posts-beams. I wanted him to asses the lack of earthquake retrofitting, and I wanted him to tell me what he thought the joists could span.

You see I thought the joists where old growth redwood, which you can not find in span tables really..

The engineer confirmed that the wood was Doug Fir and he said that it was 'at least' as strong as a modern structural select 2by10!!! Which means now, officially my joists can span 17' with no problem. Actually the farthest span I have now is only 12'-6" so I'm feeling really good about the structure.

Even, better, he confirmed that I could remove the existing post-beam, beam no post, and the load bearing wall in line with the joist situation did not need any re-inforcing.

Which means I can get rid of this post-beam in the new master bedroom!

I can get rid of this beam hanging from the joists.

I am so freaking glad of this development...the other option would of been having to use some sort of fancy engineered beam to span the spaces and I would have to dig-pour new footings for the posts...that would of been a significant expense and a huge time suck.

I was so happy about the results that I cooked everybody a fancy dinner to celebrate.

Earth Quake Retrofitting
Not so good news here... I don't know how to do it.
My simple cook book method of figuring out how much shear walling I need says that I need 23' on each side of the house!!! Because of windows that is pretty much impossible to do....especially on the short ends of the house....

Soooooo, I'm going to have to have my engineer figure out a more clever way to get a safe amount of strength in those cripple walls...

Wow, that was a lot of words wasn't it!?!?


Jim said...

"Its against code for copper water pipes to touch galv gas pipes...didn't know that."

I haven't seen that, but I see galv coupled directly to copper in older plumbing systems all of the time. I guess people aren't too familiar with electrolysis.

Anonymous said...

Foundation: Who's the conractor listed on the permit?

Joists: D Fir for joists is typical in Alameda. Redwood was mainly used for siding, trim, moldings, panels, etc. D Fir used for framing (stronger). Never seen a redwood joist.

Copper/Galv: electrolysis

Black Pipe Nat. Gas Lines: normal

The MadScientist said...

The old owner is the contractor listed on the foundation permit. I actually went all through the records and I know who the inspector was and when he signed off on the forms and all that...but just the one page plan...

Ya, def doug fir joists.

It seems like that in an exposed location on an island with some sort of 'salt air' that a corrosion resistant pipe would be more sensible? PG&E only uses galv outside.

Lady Dragonwing said...

In the case of copper to galvanized water pipe -- this equals water pouring out of the downstairs neighbor's chandelier. I lived in an upstairs apartment in a rather downtrodden Victorian that had had repairs done over the years using the bubble gum and bailing twine technique. We also ended up without water for two days while repairs were made, since no one could figure out which shutoff in the basement went to which set of pipes running every which way across the ceiling and the water had to be shut off at the main. Ah, memories... :)
Never thought about what would happen in the case of a gas pipe, but now that you mention it, yikes!

Dan said...

I found your post from Google trying to get an idea what kind of span my old growth redwood joists could manage. What do your joists measure in dimensions? Mine are actual 2"x7.75"
Thanks much!

The MadScientist said...

Hi Dan,
The joists are not redwood they are old growth doug fir. I've learned that in this area they didn't typically use redwood for structural members.
Are you sure they are redwood and not Doug Fir? If they are Doug Fir joists then according to my engineer you can use the select structural column for their allowable spans. You should use the 2by8 column, your lumber is slightly bigger so you have some builtin safety factor.