Nailing plywood onto green lumber (hemlock)

[eastbayamateur]

First post on the forum. Seems like a fantastic site.

I'm in Rhode Island, in the planning stages for a 32x30 stick built garage, planning to use locally milled green hemlock. Part of the garage will have a second floor. Likely to be balloon framed. I anticipate framing with 2x4s, bracing with let-in 1x4 or 1x6, and sheathing with horizontal pine 1x, also green. Then tarpaper on the walls, then board and batten or just reclaimed board siding (I have an old barn to tear down which will provide a lot of planking). 

For the second floor and especially the roof, I could go ahead and use more pine or hemlock 1x boards, but I'm concerned about the flatness of the floor and the watertightness of the roof. 

Question: should I be worried about nail pops or other problems if nailing plywood onto green hemlock joists and rafters? 

(I have other questions but this is the big one!) Thanks all!

[woodroe]

Welcome to the forum eastbay.
In my experience hemlock will hold a nail better than other sotftwoods.
Hard as heck to pull a nail out of hemlock once it dries. 
Ask me how i know.

[eastbayamateur]

thanks. Any thoughts on shrinkage, esp. on seams? I'm guessing it won't be a problem: the 2" side of a green 2x8 is going to have negligible shrinkage. Maybe I should try to leave a 1/8" gap just to be safe?

[Don P]

Yup, gap the seams on sheathing, it'll get wet and swell, and buckle if tight. That has nothing to do with the green lumber issue. If you do build with green framing it will take some tempering of expectations. Most boards behave, the ones that don't are memorable, for the life of the building.

[eastbayamateur]

Much obliged. I'll plan on plywood sheathing with 1/8 spacing between sheet joints. 

I have another question for a new thread. 

[Sedgehammer]

Yup, gap the seams on sheathing, it'll get wet and swell, and buckle if tight. That has nothing to do with the green lumber issue. If you do build with green framing it will take some tempering of expectations. Most boards behave, the ones that don't are memorable, for the life of the building.

even walled sheathed ones ? we always do the roofing , but never heard that on the walls 

[bluthum]

Green framing lumber will warp, twist and in the case of rafters and joists sag. There are a lot of factors that will decide to what extent all that may occur.

Then there's the board sheathing, the joints between the planks will typically shrink until there is a fine runway for mice, a little rodent freeway into their new home. Also makes it handy for them to get in place to gnaw the insulation off the romex in various spots.  

And there is the extra weight of green lumber, it will slow you down even if you are young, strong  and full of energy.

Not to say framing with green lumber can't be done but for sure the finished product will be less than if done with dried lumber.

 

[Peter Drouin]

I use green hemlock and pine all the time. Never a problem.
I think plywood on green will be fine.


 

 

 

 No plywood, just green 1" boards


 

 

 

All is good at A&P Saw Mill 

[Don P]

I've been working on the 100+ year old kitchen framing at work, there is very little left. There were 3 unmolested studs in 48' . We sawed, dried, planed and ripped new framing to the original dimensions. When the farm hand was in there yesterday he asked why we had done all that work when the original was green rough sawn. I had him look at the original framing for straightness and then at ours. By drying and then final sizing the surfaces are much flatter. Most of our original framing is oak, the new framing is poplar. Quite a difference in shrinkage from hemlock, which I used some yesterday for diagonal sheathing. I removed a couple of chestnut studs yesterday. Often they will be infill studs in local framing with oak 2x and 4x carrying the load. The chestnut behaves much better but is a weaker wood. For starters pay attention to what happens around knots in dried rough sawn, put a straight edge alongside the boards and decide if that is in your tolerances.

[moodnacreek]

The winter cut hemlock that comes out quarter and rift [straight grain, no flame] may not shrink at all in width. If I had a pile of green framing right now I might stack it in a triangle in a sunny place , put tin on top and do other work for a month or so. Green lumber is never as good as air dried.