Hod do you build roof wooden structure in US?

Hi guys.

How do you build the roofs wood structure in US?

I am putting together a materials section in my website https://roofing-area-calculator.com/materials#wood-calculator
I found out how they are building roofs in Romania but I imagine it is quite different in US.

I spoke with some guys and they told me how they are calculating their materials:
"Traditional romanian roof calculator (very simple structure).

  • beams structure 10 x 10 x 400 cm throughout
  • covered with a 2.5 cm thick wooden board
  • then a waterproof membrane (like PVC or Bitumen)
  • then smaller vertical beams (2.5 x 5 x 400 cm) - they hold the membrane
  • then smaller horizontal beams (2.5 x 5 x 400 cm) - they support the shingles. Those 2 rows of smaller beams provide space for ventilation.
  • shingles"

So I am very much interested in how do you build the roofs there in US.
What kind of beams do you use ?
How much space is between beams?
I also think there are more ways to do a roof in US but I am interested about the most generic/used way.

Cheers,
Alex

The most common in my area is to use prefabricated trusses sheeted with 1/2" - 3/4" OSB or plywood.

Some homes are built with rafters or a mixture of rafters & trusses.

I have worked on post & beam constructed homes but they are rare here and very expensive compared to our standard construction practices, these are usually built with SIP panels.

I have never seen new plank decking installed on any residence, this practice stopped completely as far as I know some time in the 60’s.

The most common roof covering in my area by far is asphalt shingles.

Thanks Axiom, what is the difference between rafters & trusses please?

Trusses come prefabricated ready to install, rafters are assembled onsite.

Rafters are commonly used for vaulted ceilings and such.

Trusses have a top cord & a bottom cord with webs in between to spread the load.

Rafters use a ridge board and usually collar ties.

Thanks Axiom.

Do you think we can work a general formula - very general - for the wood structure please?
If all the beams are in a certain distance to each other.
I am not trying to find a magic formula but to offer the roughest possible estimation for a non specialist user about the wood volume he might need for a certain roof.

Say we start from a very common roof - gable could be the most often used.
Then we look at the most common roof surface - say it has around 2,500 square feet?
Could you help me find the needed wooden beams?

Cheers

These are framing questions, I am roofer.

Wow, so you got 2 jobs in US for building roofs?
Nice.

So any framing guys can help please?

Framing is distinctly different from roofing.