Well, I guess I should have said "except for a rafter tie running the right way". It's easy to connect rafters to that, but quite difficult to catch the wall. The bolt is a great idea, and I've used a few (not on every rafter). They're immune to all the night/day expansion cycles decade after decade.In the UK we drill the rafter and tie and stick a bolt through with a spiked washer, usually M10 or M12 between the rafter and tie, then do that up tight and nail everything in the normal way.
Then also plenty of metal strapping connecting the walls to the roof at the plates and up the gables.
We normally have to bolt every rafter to the tie, it makes it much slower however as you have to place the rafter, drill it, separate them to get the spiked washer in, tighten the bolt then nail the rafter in, especially with them on 400mm centres (16").Well, I guess I should have said "except for a rafter tie running the right way". It's easy to connect rafters to that, but quite difficult to catch the wall. The bolt is a great idea, and I've used a few (not on every rafter). They're immune to all the night/day expansion cycles decade after decade.
while it is true that a certification or license (they are different) doesn't mean someone is good at their job, the lack of a profesional license does in fact mean that someone without the license is not legally allowed to perform any work that would fall under the purvue of said professional license. In the case of modifying a roof truss, I would expect a professional engineer to be involved (possibly professional structural engineer depending on the state licensing requirements). The whole concept of professional licensing is to restrict the ability to professionally offer and perform the work in question because it requires education, experince, or knowlege the general public won't have.I dont think that only someone with that cert can do the engineering. A professional certification doesn't mean someone is good at their job and the lack of one doesn't mean someone can't do the work.
But I do believe it requires more than back of the napkin math or a little internet research for an amateur
I understand the purpose and wasn't restricting my response to a question of legality.while it is true that a certification or license (they are different) doesn't mean someone is good at their job, the lack of a profesional license does in fact mean that someone without the license is not legally allowed to perform any work that would fall under the purvue of said professional license. In the case of modifying a roof truss, I would expect a professional engineer to be involved (possibly professional structural engineer depending on the state licensing requirements). The whole concept of professional licensing is to restrict the ability to professionally offer and perform the work in question because it requires education, experince, or knowlege the general public won't have.
For buildings, codes use the term "registered design professional" but, at least in my experience, building departments often accept designs by builders, perhaps relying on engineering principals and practices, in particular for 1 and 2 family dwellings and similar structures. Licensing by a government seems to have more to do with operating a business. Being certified or certificated - different - is much less clear and variable and it seems non-government.while it is true that a certification or license (they are different) doesn't mean someone is good at their job, the lack of a profesional license does in fact mean that someone without the license is not legally allowed to perform any work that would fall under the purvue of said professional license. In the case of modifying a roof truss, I would expect a professional engineer to be involved (possibly professional structural engineer depending on the state licensing requirements). The whole concept of professional licensing is to restrict the ability to professionally offer and perform the work in question because it requires education, experince, or knowlege the general public won't have.
"registered design professional" is a catchall but almost exclusively incorporates all licensed architects and engineers. it is obviously your local building department's discresion regarding what they will accept, but builders are running a business and thus what they submit should be professionally prepared - certainly for single family residential and without a doubt commercial construction. in my neck of the woods, it would only be the homeowner working on their own home who could submit plans not prepared by an architect or engineer and have the building department review and approve the work. otherwise, any plan submitted to a building department would need to be prepared by and sealed by the architect or engineer that prepared them. none of this means what was submitted is correct, viable, or even safe. that is supposed to be the function of the building department review but they are woefully inadequate in my experience at performing this function (building departments aren't generally staffed by competent individiuals with techical backgrounds - apologies if you have competent, knowledgeable staff locally)For buildings, codes use the term "registered design professional" but, at least in my experience, building departments often accept designs by builders, perhaps relying on engineering principals and practices, in particular for 1 and 2 family dwellings and similar structures. Licensing by a government seems to have more to do with operating a business. Being certified or certificated - different - is much less clear and variable and it seems non-government.
excatly - this is in a nutshell why a system like this isn't more common. there aren't discrete members taking the tension tie loads at each rafter - its the entire plywood diaphragm with that 2x4 stiffening frame laid on top at the rafter connections. the likelyhood is high that someone who doesn't understand what is going on, comes up and puts a big hole in the floor or does repair work removing portsion of the floor and then causes the walls to move outward or worse collapse the roof is a big concern. It works fine but modifying it can be dangerous.I think the only serious flaw in the technique shown is a question about what to do for repairs. With stick building its pretty easy to see which member is affected and generally to see how to replace the damage. When we get into shear skins/panels or torsion boxes/panels, the inspections and solutions get murky.
Not saying the technique is bad, just that its something to consider when selecting these kind of methods. Consider the likelihood of damage, the consequence of damage, and how to repair without compromising the original design.
On this one, what would be the fix for a storm damaged roof which soaked the entire floor upstairs and the plywood got funky? Would it matter if it got a little wet? Or was real wet for a week? Its easier to answer with 2X6 collar ties.
I'm not sure "catchall" but it is the term for a design professional who has the state mandated education and apprenticeship, and who have passed examinations, and who have continuing education to renew their registration. I think the majority of states use the term registered but some use licensed. Largely self regulated profession."registered design professional" is a catchall
In NY State it's simple - less than 1500 square feet or an agricultural building - RDP not required. Larger and it is. State law. In the OPs case, it's in between because even though the building doesn't require an RDP, the truss does. Ultimately, repairing a typical residential truss is usually not that big of deal.it is obviously your local building department's discresion regarding what they will accept, but builders are running a business and thus what they submit should be professionally prepared - certainly for single family residential
I've worked in design and construction over 40 years and would never rely on a building department review for engineering. They might tell you it's over a set back line or there aren't enough toilets, but never if the beam is big enough or not. They rely on the RDP.supposed to be the function of the building department review
Agree you might get a certificate for showing up for a few hours or a day, and even sleep through it. Being certified - which is different from certificated - usually requires documented training and experience as well as examination and continuing education. Accountants and welders come to mind. I'm certified in theatre rigging, keeping a log book of my work and continuing education and having passed an exam.a certification is not a license. people get certifications for taking a seminar or passing a test,
Amen!I've worked in design and construction over 40 years and would never rely on a building department review for engineering. They might tell you it's over a set back line or there aren't enough toilets, but never if the beam is big enough or not. They rely on the RDP.