Simplified Education of How Upper Wall Framing Plates Work Structurally

[@scRUAM]

I watch your videos just for educational purposes and not into any trades. I work in finance. After watching several videos I might give it a go to build a small storage shed for myself.

[@gregvancom]

Absolutely, go for it.

[@christopherdekonstrukt444]

Need 2x4x12s for the top and cap. May have to tie into the garage/living room wall. I'm going to have to cut holes in ceiling sheetrock and do exploratory inspections.

[@aurugger12]

As a structural engineer, if you want to make your design easy for engineering review, and there isn't alot of funny business going on in your structure, follow the Wood Frame Construction Manual For One and Two Family Dwellings - Ch.3 Prescriptive Design for your wind/seismic region. Of course, local state codes should also be considered.

[@gregvancom]

+aurugger12 I've never heard of the wood frame construction manual, is it less than 40 pages. I found it on the Internet and it is suggesting that a 2 foot lap is acceptable on homes less than 24 foot wide. Is this something you would allow as structural engineer?

[@aurugger12]

Actually, according to the WFCM Table 3.21, a 24' wall length requires 6' top plate splice length for one story, slab on grade, or 4' splice length for other cases. 24" splice length would be difficult to transfer loads through the joint without the inclusion of strapping. The splice numbers in Table 3.21 assume 4~16d common nails each side of the splice (plus 2~16d nails per foot everywhere else) from Table 3.1 - Nailing Schedule.

[@gregvancom]

I couldn't find that table, could you tell me what page it's on and whether or not your book has less than 40 pages. I've always thought it was interesting how most building plans require 16 commons, but they are rarely used and I tried to avoid using them whenever possible, because they seem to split the lumber and do more damage than a sinker.

[@aurugger12]

The WFCM is well over 40 pages. Alot of contractors use sinkers in lieu of common nails, but (hopefully) they checked with the engineer of record to make sure that the sinkers used have the correct minimum design values to be an appropriate substitute for the common nails. A 16d common is NOT the same as 16d sinker as the latter is a bit shorter and has a thinner shaft.

[@gregvancom]

I guess I should have provided you with a reason why the wood split and of course it would have been larger nails and hopefully the framer would have checked with the engineer, before using smaller nails. I'm going to try and get a copy of the book and sincerely appreciate your recommendation for it.

[@fsoileau]

When we design a structure we expect professional tradesmen (not handymen) to work on it. We expect the electrician to be an expert in using the NEC, Plumber to know the UPC and /or the NPC, and the Framers to know the local BC and RC. We expect a professional framer to understand bag nail capacities "NDS" 16d = 140 lbs shear, 8d = 100 lbs shear. We expect a pro framer to understand all load transfer in performance. Not simply downforce but dynamic forces such as shear and diaphragms. We expect professional framers to use the nailing .schedule to provide their own fix. The top plate or plates are a structural cord in tension. We use the "NDS" for engineering wood design everywhere in the US. NDS 16d nail is 138 lbs in shear. So even with older code at 48" with (16-16d nails), we get 2,208 lbs of shear force in the joint. Simpson ST6224 @ 2,535 lbs and it is a 16ga x 24".

[@gregvancom]

It would be nice, if every worker knew what they were doing.

[@christopherdekonstrukt444]

You just answered my question just as I made my last post, thank you.

[@gregvancom]

Glad to help!

[@christopherdekonstrukt444]

How do you replace existing top plate? I haven't seen any videos that actually show this, I have at least 11' of termite eaten top and cap plate at the garage overhead door. I can jack up the roof and build a support wall but how to splice the ends into existing good top plate is a challenge. Probably going to rely heavily on straps and nonstandard studs (not 16" OC).

[@CC-jy4gr]

You got that legit teacher voice.

[@gregvancom]

I think you're the first person who said that, even though someone earlier this year asked me if I was a grade school teacher. Thanks for sharing.

[@christopherdekonstrukt444]

Need to learn how to replace termite damaged top plates.

[@77Avadon77]

don't 2nd floors usually have double top and bottom paltes as well as the first floor?

[@gregvancom]

Usually double top plates and single bottom plates, unless they were going to add lightweight concrete as a sound barrier.

[@77Avadon77]

@@gregvancom thank you

[@Shanem2442]

What’s the name of the board going between top plate and bottom plate of the 2nd floor ?

[@nickcovelli5056]

Those are TJI floor joists.

[@nickcovelli5056]

I build in Idaho and we are not able to build two story with TJI any other way than double top plates.

[@gregvancom]

I've worked in Southern California my whole life and have never built a house with single top plates, but I have seen them built before. Thanks for sharing and it's always interesting to know what's going on in other parts of the world.

[@nickcovelli5056]

@@gregvancom I started my time in the industry in Southern California as well. The code requirements are much stricter than Idaho and most other jurisdictions. Never understood why anybody would not build with double top plate. It's just better, you know? Love the content. The visuals are really great and I've shared them with some colleagues who have taken the leap into residential production building. Take care!

[@christopherdekonstrukt444]

Looks like the strap overlaps both top plate boards.

[@abdullahhabibi8415]

thank you - you are amazing :)

[@gregvancom]

You're welcome and thanks for the kind words.

[@fabricebourgueil170]

👌👍👍👍

[@wwShadow7]

Is there ever a time when a 3rd 2x4 on top would solve the break issue?

[@gregvancom]

+wwwShadow7 I've never thought about that, but it seems like it would make sense. I often wonder if engineers take other things into consideration that tie walls together like floor joist or flat backing for ceilings.

[@webtheweb]

Maybe, but then you will open a can of worms with your sheathing and drywall, cabinets, plumbing, electrical, ac, etc...

[@jonathanbrazeau970]

what's a strap?

[@gregvancom]

Don't know have any videos explaining what a strap is, but it's usually a thin or thicker piece of metal with holes drilled in it. Straps are usually used to connect two boards together by nailing through the holes in the straps. Let me know if this didn't answer your question or feel free to provide me with more details in your next question.

[@jonathanbrazeau970]

@@gregvancom yeah I came across a video showing it. Thanks.

[@hickorydragon8114]

Huh huh ...he said "strap on"

[@gregvancom]

Let's not go there!!!!!!!!!