Choosing Correct Lumber Grade
Choosing Correct Lumber Grade
(OP)
I am familiarizing myself with multi story lumber construction, but I have limited experience with wood. Given the different species and grades of lumber available, how does an engineer choose the correct species and grade for a particular building?
For instance, (2)2x6 Stud grade hem-fir can be used at 16" ocs for the ground floor or (2)2x6 Standard grade hem-firs can be used at 24" ocs (both dry for shrinkage concerns).
Is there a commonly used cost and availability resource that Architects and Engineers use for pricing wood construction? Rules of thumbs, etc...
Thanks,
For instance, (2)2x6 Stud grade hem-fir can be used at 16" ocs for the ground floor or (2)2x6 Standard grade hem-firs can be used at 24" ocs (both dry for shrinkage concerns).
Is there a commonly used cost and availability resource that Architects and Engineers use for pricing wood construction? Rules of thumbs, etc...
Thanks,






RE: Choosing Correct Lumber Grade
stud grade is typically used for load-bearing walls. Be sure to check axial and bending interaction, as this may bump up your wall studs into No. 2 as well.
RE: Choosing Correct Lumber Grade
Second, use single studs down to 8" oc (if you have to go to 6"oc give a option for doubles at 12"oc) before going to double studs. This will decrease the labor.
Third, Be sure to check the double top plates for bending if you use double studs at greater than 12" oc.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Choosing Correct Lumber Grade
I have been told by many contractors that they can get any species/grade of lumber you would like but I have never taken them up on that offer (the consequences are just to great).
You will also need to spec and properties of the LVL beams you select as well (Fb, E etc...).
RE: Choosing Correct Lumber Grade
2. Do your calcs
3. Spec what you need.
Basic engineering
RE: Choosing Correct Lumber Grade
Sometimes the contractor makes the choice for you. I ALWAYS ask what material and grade they prefer to use. If a particular beam needs a higher grade, then I'll use that. Otherwise, stick to the client's preferences.
Mike McCann
MMC Engineering
RE: Choosing Correct Lumber Grade
Don't know about Northern USA.
2x and 4x ledgers, joists, beams and headers are #2 grade
4x posts are #2
All 6x and wider is #1
2x studs are usually Stud grade unless high stress requires #2
DF-L studs not recommended due to lumber twisting, use SP or H-F
RE: Choosing Correct Lumber Grade
Obviously - consult with contractor on what he prefers - but usually it is the CHEAPEST!!
RE: Choosing Correct Lumber Grade
RE: Choosing Correct Lumber Grade
I imagine that the contractor would have a handle on this, I just figured that there would be an engineer's resource that could also quantify this.
Woodman - what is the advantage of tighter spacing vs doubling of the studs (I'd hate to run wiring with 8" oc studs)?
RE: Choosing Correct Lumber Grade
Grade - #2 = straighter walls = easier to finish walls than lesser grades (I am more use to seeing/using the #2 grade for for studs in apartments)
Spacing – Double studs = labor for framer to nail together vs. easier for electrician to run wiring. As an structural engineer I have always had to deal with the framer/contractor more than the electrician, so I try to make the framer/contractor happier.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.