Not every “horizontal load bearing structure” is a joist. Terminology matters because it identifies the purpose and design of the member(s). That said… you’re not entirely wrong in this instance. Just, why would one argue for more ambiguity?
@@fomoco300k as a matter of fact, in this case I was 100% right - never said that every horizontal load bearing structure is a joist: said that a joist is a horizontal load bearing structure - not only terminology but sentence structure and word placement also matter -
Those are indeed joists. They are trussed joists. A trussed assembly can be used as joists (roof or floor) and beams. Math vs mass. Gusset plates vs nails. They are cheaper to mass produce because the math/geometry of a series of triangles are equal to the strength of solid wood.
@@fomoco300k Yes Roof joists. They’re called I-joists. I was a firefighter for 30 years. Roof construction is a primary concern with firefighting. Whenever we visited new construction sites, primarily commercial, the very first thing we would all do is look up. How was the roof constructed? During a fire, we have to ladder the building and stand in the roof, travel across the roof, cut a hole, open it up, and exit the roof. We had to know where the members were, and knowing how it was built could be all the difference in accomplishing On-Open-Off or falling through the roof. Trusses are by far cheaper to build with 2x4s along with OSB I-Joists because solid lumber is more expensive, heavier, more difficult to install, etc. Mass = Time. Solid lumber roofing members are nailed. Trussed rafters are attached with metal gusset plates at the joints. Gusset plates only have 3/8” of triangle shaped points that penetrate into the wood holding it all together. During a fire, if you get 3/8” char on the bottom chord of the truss, the truss and the load above it collapse. In residential fires, we had a 20 minute clock running beginning at the time of the call. After 20 minutes, if the was confirmed fire in the attic and ventilation had not happened yet, no one was allowed on the roof and horizontal ventilation had to be used instead of vertical. Eminent roof collapse was then expected and unless there was some immediate progress in knocking down the fire after 20 minutes, they would pull everyone out and go defensive. That was for residential build from the 70’s and newer. Before that, it’s all solid lumber in the attic and the timer was not needed. I did not like standing on trussed roofs, or roofs with I-joists. On a panelized roof, Solid beams and purlins were what we hoped for (we only walk over beams and purlins, never rafters) because of the mass.
Doesn't make financial sense for many to grow larger timber in the modern market. If it made you more money over time people would do it but it just isn't worth it.
As an ex-truss builer i can say thise trusses have my approval as well, didnt really say anything wrong with the llate teeth or the gap between the 2x4s, trusses are just really cool mathematical lego sets
First time I ever seen those I was maybe 19 and the old dude we was working for hadn’t ever used them either we threw em up and sheeted the floor then as we was standing second floor walls I was downstairs looking at this overhang it’s got with no supports come to find out the trusses were directional and we were 180 out had to reblock the load bearing side off of some engineered plans just glad I seen it and keep preaching something wasn’t right otherwise that house would’ve fell
It wouldn’t “fall”, but good save. It was drilled in me in engineering school to always, always ask a very important question… “Is that reasonable?” You’re not reasonable meter was going off and you did right by asking/calling attention to it and persisting. The contractor did right by making it good and especially by doing to engineered plans. “Aw, that’ll be good enough,” isn’t always good enough. 👍🏼
It’s the architects job to prevent this in the design phase, the contractors job to make sure it happens in the field and to collaborate with subs, architects and clients to make sure any changes happen correctly. Does that always happen smoothly and correctly? No. Not always. It takes a good, experienced contractor to coordinate and facilitate all this. And, even then, mistakes can be made.
a joist is a horizontal load bearing structure - in this case you are using trusses as joists - so those are joists and also trusses
Not every “horizontal load bearing structure” is a joist. Terminology matters because it identifies the purpose and design of the member(s).
That said… you’re not entirely wrong in this instance. Just, why would one argue for more ambiguity?
@@fomoco300k as a matter of fact, in this case I was 100% right - never said that every horizontal load bearing structure is a joist: said that a joist is a horizontal load bearing structure - not only terminology but sentence structure and word placement also matter -
Great video 👍😎
Those are indeed joists. They are trussed joists. A trussed assembly can be used as joists (roof or floor) and beams.
Math vs mass. Gusset plates vs nails.
They are cheaper to mass produce because the math/geometry of a series of triangles are equal to the strength of solid wood.
Trusses are expensive. Cost is not the reason. It’s about span, loads, deflection, etc.
Also… roof joist?? Nope. Sorry.
@@fomoco300k Yes Roof joists. They’re called I-joists.
I was a firefighter for 30 years. Roof construction is a primary concern with firefighting. Whenever we visited new construction sites, primarily commercial, the very first thing we would all do is look up. How was the roof constructed?
During a fire, we have to ladder the building and stand in the roof, travel across the roof, cut a hole, open it up, and exit the roof. We had to know where the members were, and knowing how it was built could be all the difference in accomplishing On-Open-Off or falling through the roof.
Trusses are by far cheaper to build with 2x4s along with OSB I-Joists because solid lumber is more expensive, heavier, more difficult to install, etc.
Mass = Time. Solid lumber roofing members are nailed. Trussed rafters are attached with metal gusset plates at the joints. Gusset plates only have 3/8” of triangle shaped points that penetrate into the wood holding it all together.
During a fire, if you get 3/8” char on the bottom chord of the truss, the truss and the load above it collapse.
In residential fires, we had a 20 minute clock running beginning at the time of the call. After 20 minutes, if the was confirmed fire in the attic and ventilation had not happened yet, no one was allowed on the roof and horizontal ventilation had to be used instead of vertical. Eminent roof collapse was then expected and unless there was some immediate progress in knocking down the fire after 20 minutes, they would pull everyone out and go defensive.
That was for residential build from the 70’s and newer. Before that, it’s all solid lumber in the attic and the timer was not needed.
I did not like standing on trussed roofs, or roofs with I-joists. On a panelized roof, Solid beams and purlins were what we hoped for (we only walk over beams and purlins, never rafters) because of the mass.
@@fomoco300k Relatively expensive, but try getting a price for similarly sized solid lumber...
Now that's EXPENSIVE.
A way for them to build a house out of 2x4 so they can keep using scrawny trees.
Doesn't make financial sense for many to grow larger timber in the modern market. If it made you more money over time people would do it but it just isn't worth it.
Don’t ever say “you can’t mess it up”.
As an ex-truss builer i can say thise trusses have my approval as well, didnt really say anything wrong with the llate teeth or the gap between the 2x4s, trusses are just really cool mathematical lego sets
First time I ever seen those I was maybe 19 and the old dude we was working for hadn’t ever used them either we threw em up and sheeted the floor then as we was standing second floor walls I was downstairs looking at this overhang it’s got with no supports come to find out the trusses were directional and we were 180 out had to reblock the load bearing side off of some engineered plans just glad I seen it and keep preaching something wasn’t right otherwise that house would’ve fell
It wouldn’t “fall”, but good save. It was drilled in me in engineering school to always, always ask a very important question… “Is that reasonable?” You’re not reasonable meter was going off and you did right by asking/calling attention to it and persisting. The contractor did right by making it good and especially by doing to engineered plans. “Aw, that’ll be good enough,” isn’t always good enough.
👍🏼
Legos with rules.
You better have the mechanicals planned out to miss the trusses !
You'd be surprised how meny toilets get set right on top of a truss.
It’s the architects job to prevent this in the design phase, the contractors job to make sure it happens in the field and to collaborate with subs, architects and clients to make sure any changes happen correctly.
Does that always happen smoothly and correctly? No. Not always. It takes a good, experienced contractor to coordinate and facilitate all this. And, even then, mistakes can be made.
What? Who doesn't like trusses and sound engineering?
Nice for mechanical work 😅
I miss new construction 😒
Then the farmer doesn't use enough glue and I'm chasing squeaky floors for the next six months.
Those floor trusses are complete junk . They are never the same length and they are prone to floor squeaks
And if your house catches on fire it'll lessen your escape time quite a bit.
@@jamesmadson3242 bar joist , open web , or solid joists will burn at the same rate once the floor is engulfed in flames
I’ll take I joist any day, those are so heavy and you better hope they make a them correctly.
🤣 P R O M O S M
???? What does that mean?