Hello Brothers and Sisters...

I know... it's either "Who the hell is this guy?" or "Where the hell has this guy been?"

Well, my work today prompted me to issue a hopefully helpful warning to industry fellows who might be retro-fitting super slap em up homes by builders like D.R. Horton. Luckily, it's been a while since we've done one. This particular job was running Cat6 as the builder has gone so cheap that the woefully undersized 14" enclosure has been cut down to a 2 gang metal p-ring with a cable splitter jacked sideways in it and a 120V outlet beside it... low in the master bedroom closet. A walk of a current house in framing reveals that 24" OC studs and single top plates are now the norm. Moreover, wood at the wall tops for lid nailing has been replaced by 90 degree angle metal attached to the top plate.

I asked the site supervisor "WTF... are you guys afraid of wood?" His reply'..."Less wood, more forests". Guess I can't argue with that but I'm sure there's a little profit motive there too.

So... the significance of this? While doing the attic balancing act that I've done many hundreds of times, it became painfully apparent that the wood at the wall tops for lid nailing, which has been replaced by 90 degree angle metal attached to the top plate, used to contain the 1 5/8" drywall screws that now protrude up like little death spikes. Ice cold beer and Advil have not yet salved the gouged pinkie, punctured palm and the small hole in my head from the roofing nail because I rose up fast when one of these f*&^#rs, hidden by insulation, scraped across my patella. I haven't had a tetanus shot in 7 yrs so you can guess what's on my list tomorrow. There is definitely some Roland blood in that attic.

Anyway, be careful if you are working in one of these cheaps#*t crackerboxes! You've been warned...

good warning. not just for safety but what to dispel ANYONE from buying.

D.R. Horton is known for their crap houses. You're better off in a homeless shelter, than to purchase one of their waste of material structures.

If you still have the "shot card" with that tetanus shot on it, let the medical staff look at it. Because I received one about 7 years ago to, and it's good for 12 years or something like that. If you don't know, ask if you can have one anyways even though you maybe with in the "12 years".

Also, how much are these homes going for once completed? 3-bedroom/4-bedroom?

KOT

Good heads up.
Im curious in what state these D.R. Homes are in, i've never heard of those.

I know they are I. Oklahoma, by brother bought one a few years ago, besides pouring the wrong foundation floorplan, they have had.no issues....yet

This news cast is from 2014... Yet they are still in business today.



KOT

I've never seen a home built without top plates on the walls, but the metal pieces you mention are actually there for a purpose, and they would be there regardless.

They will virtually eliminate truss lift problems since the outer edges of the drywall are not connected to the truss system. The truss can lift as it will in cold weather and not cause the drywall to pull upwards and away from the wall, which has always been a problem with truss constructed homes.


Not the only way to solve the problem, but it is used quite frequently.

Here's a good explanation: [Link: carsondunlop.com]

Ah. So this only happens to interior walls, not perimeter walls.

Well, I read what they're saying but a lot of it doesn't make sense. In the drawing they present, they show everything but the bottom chord expanding. The bottom chord contracts.

Seems like that would make the roof push outward at the perimeter walls and stretch the bottom chord extra tight. Instead, something pulls up on the bottom chord. If the webs shrank, that would pull the bottom chord up. The expansion and contraction they show would also seem to make the roof chords move upward, since the bottom chord keeps the perimeter walls from getting any further apart... so I wonder if this movement is a fact but they don't actually understand it ([sarcasm font on] because, of course, I'm perfect and I understand it....[sarcasm font off]).

I'm not saying it doesn't happen. I'm saying their explanation doesn't match the forces as they describe them.

I'm in Washington state and this 2700 Sq Ft 4BR 3.5Bath house is in the low 400s. 25 miles north of Seattle.

TSS... thanks for the explanation... I'm always interested in construction techniques. This one is new to me though... never seen it here before. If its the new norm then I guess we all better communicate this to the attic crawlers in our companies. These screws stick up a full inch... enough to stab right under a knee cap!

Here's another source that goes into this and it agrees with the picture. The title of the link says it all- "Wood is good, but strange".

[Link: buildingscience.com]

This all comes from empirical testing, not conjecture.

Thanks for that article link. I haven't the time to read the entire thing right now, but I hope there's something in it that really does explain the drawing, since I'd like to understand it. I'm left skeptical, though, by this:


The arrows in the above drawing show expansion and contraction in the direction of the grain, not at a right angle to it. Now, it's totally possible that the arrows on that drawing were intended to indicate that the wood gets thicker and thinner, but the direction of the arrow points is wrong for trying to get that idea across.

I was originally going to comment on the direction of greatest dimensional change, and I think it has a lot to do with the total problem with this issue, but the changes to the top plate wouldn't matter much since it's in direct contact with the bottom chord. I also think it would be easy to think of whether the members are in compression, tension or neutral when looking at the diagram.

Having sat through a lot of videos about this in high school and college (I studied architectural building construction at an engineering school) and the % elongation is small, but the effect is larger than expected due to typical length of the components. The cross-members would have little effect.

The arrows are marked as having to do with expansion during decreases in temperature. It's counter-intuitive, partially because temperature change also comes with humidity changes and the two are linked in real-world environments, as anyone who has cut lumber hours or a day before construction knows. Hell, even stacking lumber with stickers doesn't always go well. I bought some studs at Home Depot one day, stacked & stickered them and the next morning, I had a pile of skis. Total crap- last time I wasted my time with their wood.

If and when I build, I'm not going to let the builder tell me where the lumber comes from.

24" OC Studs and single top plate increase energy efficiency. This allows for less thermal bridging from using the additional studs (16" OC) and increases the R-value of the entire assembly.

Building Science also has articles on that as well.

That may be true, but structurally, it's significantly weaker. Also, in moderate climate, the difference in R-value is insignificant because the temperature differential is low.