Maple Heart Wood

[jrfroe]

Does anyone know where I can find design values for "Maple Heart" Wood? I'm trying to check 3x8 planks (laid flat) for a construction load and can't find anything in the NDS manual or from an internet search. I'm not sure what grade the planks are, or even if this type of wood is usually visually graded like every other species.

Thanks,
Jason

 

[YoungTurk]

I'm guessing you have maple heartwood, wood from the heart of the tree; as opposed to maple-heart wood. Possibly cut as such for aesthetic purposes?

From the Wood Handbook, page 1-7:

"Heartwood and sapwood are similar in appearance to hard
maple: heartwood of soft maple is somewhat lighter in color
and the sapwood, somewhat wider. The wood of soft maple,
primarily silver and red maple, resembles that of hard maple
but is not as heavy, hard, and strong.
Soft maple is used for railroad crossties, boxes, pallets,
crates, furniture, veneer, wooden ware, and novelties."

Unfortunatley there are no other references in the handbook. Not sure if that helps, but you never know...

As a disclaimer, I'm no wood expert, I just worked a few years at the Forest Products Lab. They are, by the way, very much experts and open to contact for questions such as yours.

 

[SlideRuleEra]

The 2001 NDS Supplement has information on Maple. It is graded by the Northeastern Lumber Manufacturers Association (NELMA) - NDS has incorporated their findings in the Supplement. Values for "Mixed Maple" planks of various grades are given on page 11 of 24 at this link

http://www.nelma.org/files/File/Chapter_8-2006_Grade_Rule_Book.pdf

Even at it's best, it does not have particularly good structural properties. Suggest making a conservative estimate of the properties, apply the appropriate adjustment factors and seeing what you get.

http://www.SlideRuleEra.net

 

[YoungTurk]

Personally, I'm not sure if general maple properties should be applied to heartwood. In general, juvenile heartwood has signicantly different properties than the mature wood do to the higher growth rate and various other growth factors.

I recommend you broach this topic over at the wood design and engineering forum under materials engineers if you are going to be using the material in a significant structural capacity.