Using Sweet gum for a timber frame

[fishfighter]

I have a bunch of sweet gum on my place. I know it is a soft wood and easy to rot. I would seal it once finished. I'm looking to build a small timber frame building on a island in my pond. Of course there will be no ground contact with the gum. The building will be open on all sides. Size will be about 12'x16'.

[Magicman]

Wow I can't answer your obvious question, but pith centered Sweetgum timbers should remain fairly straight.  I sawed several hundred this year, most of which will be used on outside screened in porches.  Even sealed, you would want to avoid any roof runoff splatter.

Sweetgum makes good board and batten siding if the above mentioned splatter is avoided.

[fishfighter]

Was planning a 2' overhang. There will be no siding at all. The gum I have are a avg size of 15" BH and easy 35' tall and straight.

[Southside]

I have sawn quite a few gum timbers myself and they do behave well, if as MM said you center the pith and don't try to get more than one per log.  

[fishfighter]

That was my plan. But as for as rafters, I would try to get what I could out of a log.

[Magicman]

They's gonna twist. 

[fishfighter]

What if I wait and saw them and put them up green? I would lock them in and strip them on top for a metal roof.

[Magicman]

I don't know. 

[YellowHammer]

I made some rafters, actually trusses, out of hickory some years ago, then put a metal roof on them with standard metal roofing screws, and within a short time, the roof was leaking.  Turns out the hickory would move some and it was stronger than the metal roofing tearing the screw holes in the metal panels and cause them to leak.

If I was to use a sweet gum for rafters, I would brace or block it like crazy to make sure it wouldn't tear holes in the metal roof like the hickory did.

Putting substantial strips on top of the rafters might do the trick.  

[scsmith42]

For timbers, I tend to see less twist in sweetgum if I let the logs age for a year or so.  Yes, they will get bugs in them but they seem to stress relieve somewhat while they are aging.

I don't recommend this for other species; and if you do it peel the bark off and soak with a 15% Timber solution.

You can also mill the posts significantly over size, air dry them for several months and then resaw them square if they twist.

[fishfighter]

For timbers, I tend to see less twist in sweetgum if I let the logs age for a year or so.  Yes, they will get bugs in them but they seem to stress relieve somewhat while they are aging.

I don't recommend this for other species; and if you do it peel the bark off and soak with a 15% Timber solution.

You can also mill the posts significantly over size, air dry them for several months and then resaw them square if they twist.


Was planning on over size post and beams. As far as felling them and letting them sit for a year, I don't have a place to store them out the weather.

Still in the planning stages with this.