Building mags - what does this mean? (Foundation terminology)

[Rock Knocker]

I'm seeing joists run parallel to beams. I'd assume beams are to joist height since he said they're there to carry bearing walls above.

The beams run E-W. The floor joists run N-S as per plan note and the flooring detail which indicates the long axis of the subfloor as running E-W

[house]

I'm confused ( a perennial state)....you state the longest span of the joists is less than 10' due to the 4x8 beams....how so? are your joists are running perpendicular to those beams? in which case I don't understand the ledgers....but I do see the arrows on the drawings...
What about the 4x8 beams...they are the same height as the joists?

Right, joists will run parallel to existing house's adjoining wall. The addition is about 36' long, and joists will be hung in the four "squares" created by those beams. The plans call for 8" ledgers (same as the beams, so 7.25" actual). Note that 8" I joists are spec'd in the plan, but 9.5" is the smallest typically sold. If I can get shallower joists I'd like to (any extra depth to the crawlspace is welcome), but if we need to use standard 9.5" ones, the hangers should attach to the ledgers/beams just fine.

[train07]

why not drop the beams and let the joists sit on the beams? a lot less hanger work and your bearing will still be where you want it

[Alpinord]

Happy ending - no responsibility needs to be taken. The architect stopped by to take a look, and while he wasn't thrilled, he admitted it was overbuilt and that we can still attain adequate shear hold down. He says using 4x bottom plate on that shear wall above the opening, anchoring it to the foundation, and nailing off the sheathing to that fat bottom plate should suffice. Someone mentioned the need to hang joists - and yeah we'll probably size up to a 4x ledger to span that opening (for those who haven't noticed - joists will hang from a ledger anchored into the stem wall).

All those pads are for posts supporting 4x8 beams. These beams hold up bearing walls in the addition above (edit: only two walls; no bearing wall above the center two pads). This is a one story addition, so I think it'll be pretty stout! Longest span for floor joists is <10' due to the beams, so we can use shallower floor trusses/I-joists and keep a decent crawlspace depth. Full floor framing pic:
Attachment 280742

Anyone here have experience with trimjoist type floor joists? Architect is concerned they have more bounce, since they're built from 2x oriented flat, but with our short spans I think we'd be fine (I have stayed at a holiday inn express). I like the option of running ducting through the open web of the trimjoists. https://trimjoist.com/. I haven't taken the time to look at stiffness specs but I presume those would enlighten the "bounciness" question.

Open web truss joists are designed just like roof trusses for what ever stiffness, loads and spans you need. You can even have them designed with plenums sized to fit larger ducts than might fit in the openings (coordinate with your mechanical needs, 1st). They are sweet for running everything vs having subs over drill joists or fighting for space for their runs. You can also design them with top chord bearing.

[house]

why not drop the beams and let the joists sit on the beams? a lot less hanger work and your bearing will still be where you want it

Looking at it again, I think that's what he's drawn up. Makes sense, but I've been approaching everything trying to maintain a useable crawlspace so I had it in my mind that we'd be hanging joists off those beams. We might have some real clearance issues if the joists sit atop the beams, and the HVAC trunk line runs below those beams. I spent 5 hours spelunking through the existing house's crawlspace recently, so I have strong feelings about being able to access stuff down there. I don't mind pounding in some extra tico's if that's the route we go.

[lifelinksplit]

The beams run E-W. The floor joists run N-S as per plan note and the flooring detail which indicates the long axis of the subfloor as running E-W

Guess I should've actually looked. That's what I thought at first but the OPs wording confused me.

Anywho good luck with your project!

[train07]

hvac might be able to go between the joists and above the beams..
how often you going to be spelunking in this new crawl space at the beam locations?
but strong feelings are strong feelings...
and yes, best of luck

[house]

how often I go down there may be directly proportional to how comfy I can make it.

"Dang! It sounds like that electrical pipe under the house sprung an oil leak again. Better go check it out." -Me, next time I need a little peace and quiet for a while. (Decent wi-fi under the house if you ever have a game to catch, too. Just tap on a pipe or floor joist every few minutes and you're golden).

[ctsmith]

Trimjoist’s or similar will work fine, just size them so live load deflection is less than L/480

[train07]

ahhh .. a secret mancave!
an automotive technician's creeper will get you to your favorite chair!

[fastfred]

Never ever over think home building. Rule #1.
Afternoon bong hits serves me well rule #2

Ten guys doing whatever they want with no supervision is not a good idea. I left one guy all alone on his first day hope he works out and knows how to tie rebar like told him.

Payday is tomorrow hope there is enough bank in the bank.

[RockinB]

how often I go down there may be directly proportional to how comfy I can make it.

"Dang! It sounds like that electrical pipe under the house sprung an oil leak again. Better go check it out." -Me, next time I need a little peace and quiet for a while. (Decent wi-fi under the house if you ever have a game to catch, too. Just tap on a pipe or floor joist every few minutes and you're golden).

I did some survey work for a old elementary school that had been out of commission for over twenty years. The school district was planning on turning it into a faculty for the maintenance staff. I guess when the engineer went in the crawl space it was a sea of empty beer cans and there was a sofa down there. Apparently the school maintenance guy had the same idea as you.

[Foggy_Goggles]

Sounds like a bit of a nightmare. I'm assuming you are the framer? We all like to point fingers at the other guy so here we go.

a. you scallyway concrete crew just ignored the plans, at bare minimal they should bear the cost of the resign. It's a fucking window buck, plain vanilla shit.

b. the architect/engineer specs a 8" TJ? Sweet, just like the job I'm working on that specs a 26' 2x12. A then you want to whine when I, the framer, tell you we need a plan correction form and you have to create some details for the point load (can't birds mouth) and sistering. My job would be easy to is I could just make up products as needed. How do you do a span calc for a product that doesn't exist?

b. If it is drop beam, you probably needed to have beam pockets in your foundation walls or at least pads/footers to carry the load.

[/contractors rant] I so over the "if I fuck up, it costs me money...if you fuck up, it costs me money". This project is classic, it is a god damn +/- 13' 36 addition. I should be able to back the trailer up to the job, get out the laser, start snapping lines and have the floor sheeted by lunch the next day.

But no that is not how it works in 2019.

[RootSkier]

So you are digging, forming, inspecting (maybe), and pouring footers and walls on the first day? Seems quite aspirational.

[train07]

OP opened up a cans of worms... the dentistry requires an elevation section showing the relationship of the beams to the new concrete wall and the ledger(s)

[fastfred]

So you are digging, forming, inspecting (maybe), and pouring footers and walls on the first day? Seems quite aspirational.

some people know how to get a job done and make money
on the other hand I'm in a tshirt and my underware doing laundry posting on tgr and trying to do paper work
winning

[Foggy_Goggles]

So you are digging, forming, inspecting (maybe), and pouring footers and walls on the first day? Seems quite aspirational.

Framing only. Nobody want to pay me the do the foundation, they should. It would be correct. Grinding on the top of foundation, that is extra. That 1" gap under the sill? Maybe you should have used a level and pulled square before you peeled off that stack of hundred as the concrete truck was washing down.

Train, elevations? Customers get what they pay for with plans. Often times they are looking for the bare minimum to get the plans stamped and the permit issued. Framing is design build. After the first couple calls to the architect asking for clarification to do it right you just say fuck it and over build everything and hope that the inspector can't read the plans (or doesn't look).