I am not clear which type of wood is stronger for building a home,
garage for rafter.
I used 2x12 for my garage and currently I have the same on the house,
now I need to rebuild the house, now the question is the structural
rafters which is make of 2x4 vs. OSB rafters used with two 2x4 in the
shape of I beams vs. regular 2x12 which one is better, of course 2x12
got to be more expensive and less tree friendly.
It's not about which is "stronger". It's about which is suitable for a
given span. You speak of two products... standard framing lumber and
engineered lumber. Both come with span tables.
Having been a framer for several years, I've had experience with both
and I can offer a few comments...
The use of engineered members is normally specified when the span
required is greater than that which normal lumber can span. In other
words, due to a greater cost, use it only if you need it. There is the
claim of labor savings in floor applications, but from my experience,
the savings are minimal.
In applications where normal framing lumber would be used, engineered
members can offer greater stiffness... if you're willing to pay the
added cost. (We're talking floors here.)
In my experience, the lion's share of engineered members were used in
floor applications rather than pitched roof applications. The few
instances where they were used in a roof assembly were in homes with
monsterous open spaces and high vaulted ceilings... and even then,
normal lumber was used in less demanding roof areas.
From the carpenter's perspective, engineered members are a little more
difficult to work with... and that goes double for using them as
And I think your notion of "tree friendly" has no usefulness in the
discussion. If you're really interested in being tree friendly, build
the home using steel framing. Then again, if you did that, it might
not be so "strip mining" friendly. You could always build a home from
excess brush you find in the woods ;-) But then it would be a fire
hazzard. Options are running thin here.
Thanks Joe for grate comments, now here which type if engeneerd lumber
you are referring to? the one made of OSB with two 2x4 or all made of
2X4 or they are some other type out there you are talking about.
The floor will span about 40 feet which with regular lumber I need to
use 3 14 feet or so, where I assume I can order engeneered lumber in 40
feet, I hope.
Yes, the most widely used engineered member in residential
construction (other than laminated headers) are Trus-Joists...
http://www.trusjoist.com/ These are the ones that have something like
a 2x2 or 2x4 on top and bottom with something like OSB in the middle.
You mean you hope it won't break the bank. 40 ft is a LONG way for
standard wood frame construction to span... even with engineered
Methinks your plan needs a rethink.
Also, try alt.building.construction. Lots of knowlegable construction
folks there. Tell them Joe Barta says "wazzup y'all!"
Hopefully he has some beams under the 40 ft span. Anyway, to the op,
40 ft trusjoist are easy to get and easy to work with (but you can't
span 40 ft. free with them).
(remove all letters after y in the alphabet)
I really like the BCI beams for floor joists. I've never heard
of them being used for rafters. Besides being a "greener"
material using less lumber more effectively, it retains its
strength even when you punch big holes through it for utilities
and wiring. And it's a lot easier to do than in dimensional
An engineered joist can be manufactured to span larger areas than normal
Say you are going to span an distance of 30' (floor). The engineered joist
can be made in several configurations and set on different centers.
Dimensional lumber would be much more expensive for the same span and
options for size and centers are more limited.
For flooring and commercial roof applications, an engineered joist is
generally preferred for cost savings and configurability.
I really don't mean to sound like a jerk, but........
After reading your post, it doesn't seem like you have enough grip on
the situation to be doing it yourself. For the type of spans your must
have if your considering engineered joists for rafters, I would think
you would want the advice of some lind of professional (Architect,
engineer or a framing buddy). I have been a carpenter for 11 years (4
framing) and have never seen I-joists used for rafters. I've done some
pretty big jobs too (Not saying it isn't done or that it isn't an
the manufacturer here http://www.trusjoist.com/ showes they are used
for roof as rafters, however I was more concidering for the first and
second floor, for roof I would go with pre build constructional 2x4
material, the only drowback is then I would not have a usable space
under the roof. If not that then I would rather go with 2x8 douglas
fire wood, which I used for my garage, but the max length I fould was
only 20 feet which will be short for a 40 feet spanned floor.
Even they have the same material for studs.
So any how I can ask my architect to drow the plan base on these
engeneered material and he kind of figures out the load capacity and
other required information for the permit, I just got to find out first
if they are better and second if the price will be lower that regular
you tell the architect that you want a building of such and such a
style for a given site within a given budget and suitable for a given
purpose. you let the architect design it. then the architect sends the
design to the engineer for structural review. you don't tell the
architect what kind of joists and rafters you want used. they go to
school for a long time to learn how to design buildings- it's their job
to figure that part out.
I agree with you in sime degree, not all. Good ideas is every where,
architechts design what they learned, the diffrent between a architecht
and normal person is they can bring on the paper what they think but
normal people can just think and see thinks in the head, that's why you
go to architect to pring your idea on the paper so the vilage or city
can review them for permit.
My 30 and some year experienced architecht drew the blue print of my
garage with lots of input and ideas from me, of cource he did had lots
of ideas I did not know anything about it at all, when the cancreat
contractor was looking on the job for estimate, he did corrected, or
better improved what architecht designed for me. by end of the project
I did added some new items to the garage wich made the garage most
unique in the neiborhood.
The lumber supplier did fixed some weack design as well.
So what I am saying I do not rely 100% on some one only because he/she
went to school, some time you learn a good think from a little kid. So
I am affraid to tell architect what I want or how I want. that's may be
Thanks for advice anyhow
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.