Rafters

[Rhodemont]

I am going to start the build of a post and beam garage/barn next spring.  I would love to be able to build it timber frame but just do not have the skill to do that.  So it will be structural connectors.  The posts and beams will all be oak I log off my property and mill.  It will require 16 foot roof rafters. Not much white pine on my property that would be good to make them. They also could be oak but that would be very heavy and difficult for me to work with. I have a lot of Tulip Poplar that is straight and clear that mills well.  Will the Poplar be suitable for rafters?

[Don P]

Poplar and oak here. They whined when I passed them oak. (I had handled each stick how many times by then  :D) Do borate the wood.


 

[Jim_Rogers]

If the rafters are good grade and sized correctly for your loads as well as spaced correctly, they should work.

Jim Rogers

[Rhodemont]

OK guys, all oak for posts, beams and framing on the first level with poplar for the rafters.  I will use my FEL to lift and position all the oak.  Poplar for roof frame will still be heavy but lighter than oak.  I am also counting on the poplar (providing I mill and sticker properly) to be nice straight and uniform without likelihood of oak moving and cracking as it dries.

[Don P]

Why would you count on that?

[Rhodemont]

The  poplar that I have are the straightest clear tall trees that I have.  The couple of trees I milled in the past came out with very straight flat 2 x 8 x 18' boards.  A friend used them to line a run in shed and couple years later they still great.  A percentage of the oak I have used for run in shed rafters have moved and split some as they fully dried even though they were straight and flat when installed.  I realize installing the oak green will lead to that which gives the posts and beams character. 

[Don P]

The frame above was made as framing is typically done, just on small equipment. Saw, dry, plane, straightline. I found it very tight trying to get 11-1/4" out of a rough sawn 12" wide in poplar. It depends on end use but it can do some moving as it dries too!

[Joe Hillmann]

I have milled about 300 poplar rafter over the last couple years.  They are the best behaved wood type I have come across for using as beams and partial log construction.  They don't twist or crack when they dry.  I also did some ash, pine and maple rafters as well.  Those other types of wood all have large crack in them from drying, some of the ash has almost ripped itself in half and has almost twisted itself into a propeller.

Poplar is also nice because when grown in a thick stand it grows nice and straight without a single knot in the lower 40 feet of the tree.

When dry poplar is pretty light. I recently had to move a pile of rafters that I milled last fall and this spring.  When I milled them I struggled to drag them the 10 feet off the mill because of their weight.  Now that they are partially dried I was able to lift them up on my shoulder and carry them to where they should have been put originally.

[Rhodemont]

I do not run my mill during the winter, that is when I will be doing the logging while the ground is frozen.  I am planning to start the milling in March as soon as starts to warm some.  If I do the poplar first will air drying until September provide enough time for those that want to move some.  I will mill extra in case any really get ugly. 

[Don P]

If you can mill and have the surface dry before the bugs and mold it helps. With these two, bugs more than mold as the concern. If you are comfortable, so are the bugs. Borate green from the saw. The poplar in 2x will be dry by Fall, the oak as timbers will have some surface drying but will be far from seasoned.

I am fussy with framing. My way will work but it is labor intensive. I remove the moisture and then remove everything outside of my desired nominal stick. Many folks use framing right off the saw and are happy with those results. Your expectations are the gauge there. Do not pick one way and expect the results of the other, that is the insanity I see most often  :D.

@Joe Hillman, are you describing tulip poplar or aspen?

[Rhodemont]

I purchased a Powermatic 20 inch planer and 10 foot roller tables from a friend.  I plan to finish plan all dimensional lumber to  nominal size.  The rough lumber for a shed is no problem but I can believe irregularities would be an issue for framing.  It will probably be good to plane the columns and beams ...that will be a chore.  Many of the columns and beams are rough milled,  if the weather holds I will get some more done and be ready to clean them up come spring.

[Joe Hillmann]

@Joe Hillman, are you describing tulip poplar or aspen?

Not sure.  I am in Wisconsin and locally we call it popple.  It is probably much closer to aspen than tulip poplar.  Although I think aspen don't get quite as big as our popple do.