what is better for framing lumber syp or poplar
SYP
Yup, I wish I had that option as I was framing with poplar this week.
I did a demo for our local USDA and Forestry dept last Feb and the Forester advised there the specs for poplar were real similar to pine so you won't be too bad off using either as I understand.
Engineering specs are one thing, behavior of the wood is another. SYP would likely be the winner in the manners department. Poplar has always done its own thing for me, and that usually includes some serious bowing.
I do poplar SDR, saw-dry-rip and it works fine that way. I framed a small 16x28' house last year mostly with poplar. Using that technique I'd put it up against box store framing any day of the week as far as straightness.
This span calculator is from the folks that write the tables in the codebook and has both species;
https://www.awc.org/codes-standards/calculators-software/spancalc (https://www.awc.org/codes-standards/calculators-software/spancalc)
If you run the calc for 2x12 #2 poplar floor joists, max span is 16' which is what we did although most of the material was select struc., poplar is usually pretty easy to find nice wood.
Run the same thing in SYP and max span is 16'6" so as Howard said apples to apples not a huge difference.
Poplar does attract ppb's here so we treated both at the mill and then the finished frame with borate. The project this past week is a 120 year old timberframe with rot, ppb's and termite damage. I soaked the framing we were working on pretty heavily Thursday evening, put in foam insulation yesterday and will hopefully start residing that section next week. The windows we are making are poplar as is the siding that a local millwork shop reproduced.
That said if SYP grew here I would probably use it for framing.
Lots of stress in yellow poplar here, especially in smaller trees. Saw-dry-rip would help resolve those problems for sure.
I refuse to saw framing lumber from 18 year old Plantation Pine with ½" growth rings. If the customer insists, I saw one and show him why.
Yesterday's framing lumber was sawn from 75-80 year old trees with 1/8" growth rings. Good stuff.
Be aware that there are several species of trees that are locally referred to as "poplar", with very different characteristics. Quaking Aspen and Tulip Poplar are not at all the same (and neither would be a good choice for framing a house). This is one case where using the scientific name can avoid confusion.
thanks for the info i have plenty of both so i guess syp it is thanks again
I have used tulip poplar on some framing material for a pole barn. Man was it a challenge to saw due to stress. Most all of it cut from a hill side. Made some great rockers!