Ipe Hardwood 1

[epitome1170]

Has anyone ever worked with Ipe Hardwood and have design values for the lumber?

They are not in the AWC NDS, but I found some values in the Dept of Agriculture website, but these values need to be decreased and I am looking for an idea of by how much.

 

[Brad805]

I have a $12k stack of Cumaru at a friends place (hobby). Cumaru is not quite as dense as IPE, but it is very close. I have also worked with a quite a lot of Jatoba and Tigerwood. I am sure you know how dense these woods are. The problem I see is you will not have anything graded. I highly doubt anybody is too concerned about grading rules in South America. The most common uses are non structural. Advantage lumber has a few more specs also.

http://www.advantagelumber.com/ipedecking.htm

Brad

 

[epitome1170]

Thanks Brad. That is what I was seeing as well.

Luckily this is for a residence as opposed to commercial practices, however, the landscape architect hired me on to check his drawings for structural items and this is one last "loophole" left to close that I was hoping some direction would be provided on.

 

[HeavyCivil]

I think they're off by a decimal place on their reported bending strengths..

 

[epitome1170]

VTEIT

Meaning you think it should be 2,250 psi as opposed to 22,500?

 

[Brad805]

I found another supplier that has similar data. I can't honestly say I have ever looked into its structural capacity for my uses.

http://ipe-wood.com/tech.html.htm

 

[JAE]

IPE sinks in water and is very dense. You have to pre-drill holes for screws. You cannot nail into it.

 

[HeavyCivil]

epitome - yes I think it should be 2,250.

12,400psi is listed for doug fir. I think we can agree that no combination of adjustment factors would get you there...

They do list this as 'Bending STRENGTH' as opposed to an allowable stress. I'm used to working with wood in ASD, so I imagine the strength is much higher, but I dont think the NDS and grading agencies would be very popular if they applied an FOS of 10+..

 

[JAE]

Here is an FAQ which was found here: Link

[blue]Where can I find design values for tropical hardwoods, imported species, or other species not listed in the NDS Supplement?

First check Table 2.1 - List of Sawn Lumber Species Combinations beginning on page 4 of the NDS Supplement. Design values for the species listed in the NDS Supplement are provided by the grading agencies.

The 2005 NDS supplement Table 4F has non-North American visually graded dimension lumber including:

Austrian Spruce - Austria and the Czech Republic
Douglas Fir/European Larch - Austria, Czech Republic, Bavaria (Germany)
Montane Pine - South Africa
Norway Spruce - Estonia, Lithuania, Finland, Germany, NE France, Switzerland, Romania, Ukraine, Sweden
Scots Pine - Austria, Czech Republic, Romania, Ukraine, Estonia, Lithuania, Finland, Germany, Sweden
Silver Fir - Germany, NE France, Switzerland
Southern Pine - Misiones Argentina

As for other foreign species such as mahogany, ipe, greenheart, etc., or domestic species such as ash, locust, magnolia, walnut, etc., there is some design information in the Wood Handbook published by the US Dept of Agriculture Forest Service, which can be found at

http://www.fpl.fs.fed.us.

However, since these values are average unadjusted ultimate values, they need to be adjusted per applicable ASTM standards, such as ASTM D245, to arrive at allowable properties. A further complication is that if lumber is not grade stamped in accordance with American Lumber Standard Committee (ALSC) rules:

http://www.alsc.org/,

there is no way of knowing what type of product will be used in construction. Engineering judgment will be required to use these types of foreign species in structural applications. [/blue]

Also - The Wood Handbook referenced above has Chapter 5 (found here: Wood Handbook Chapter 5 which shows material properties for IPE (see page 23)

I’ve attached the relevant table for IPE.

 

[Brad805]

I agree with VT the values listed are ultimate values direct from the test samples. I checked to see what Fa value they are using in the one span table assuming they were governed by bending only. By a couple of quick calcs it seems the Fa value they used is between 1300psi and 2300psi. The longer span, lower loaded elements are likely governed by deflection, so I suppose the 2250psi number is probably a good number to start with.

 

[graybeach]

I used IPE for the deck on my house. There was some design information about it in the various home deck books, mostly what spans you can have. It's a lot stronger than any of the various firs and pines. It is very heavy too, and it has to be end sealed with wax.

Another thing I found out that was that the dust from sawing and sanding is irritating to one's lungs.

It looks awesome, and I love how it came out. A total bear to work with though.

 

[Brad805]

VT, I was not replying for the sake of arguing. It peaked my interest for some odd reason.

 

[HeavyCivil]

Brad805 - sounds like we were in agreement, not argument.

Graybeach - bet you burned through some skillsaw blades with that stuff!

 

[a2mfk]

Brad- your hobby is collecting ridiculously expensive wood?

"I have a $12k stack of Cumaru at a friends place (hobby). "


Sorry, couldn't resist, that comment read funny to me.... I'd like a $12k stack of anything, and I would never leave it at anyone's house.

 

[Brad805]

a2, I convinced some friends to use Cumaru for their new deck and shortly I am going to put it all together for them. Why you ask? Sometimes I wonder why I can't just nod and smile. I have done a lot of these projects in my spare time in the last few years. Not too long ago I had a 6,000lb pile of Jatoba stacked in my garage. They were quite the challenge to move around. 90% of them boards were 13" wide x 24' long. That wood was so difficult to work with I finally replaced the cutterhead on my planer.

I guess one might say I have a bit of a wood collecting problem.

Brad

 

[ToadJones]

Brad-
I feel your pain.
I currently have about 400 sq ft of Brazilian Tigerwood Flooring, about 350 sq ft of clear cedar 5/4x6 decking along with numerous clear cedar 2x4's and countless other building materials in my possession (including enough carpet to do a small house).
I don't know why. None of it is for projects at my house. People have asked to buy them, but I cant let go. Luckily none of it is at my house.
I think everyone has a buddy that is "that guy" that is the part time builder/DIY guy.

 

[a2mfk]

Though I had nothing like the hoarder levels of construction materials that you guys have stockpiled (nor near the value), I moved about a year and a half ago. Let me tell you, 8 years in a fixer upper house had lead to a vast array of misc materials, most of which I asked myself "Why the hell were you saving all this crap?"

Cause you NEVER know when you may need a circular piece of gyp board or a box of ceramic tile pieces, that's why!

 

[Brad805]

It is nice to see there are a few more of us engineers with a wood hobby. When I get real bored I start re-inventing parts of my machines.

I moved the home my parents built on the family farm in the early 70's and have been working on that since 2005. I wish I never would have started it.

Brad

 

[Cadair]

VTEIT,

The decimal place is correct, it is just reporting a completely different value. As JAE quoted from the American Wood Council's website....

"However, since these values (in the woodhandbook) are average unadjusted ultimate values, they need to be adjusted per applicable ASTM standards, such as ASTM D245, to arrive at allowable properties."

These "adjustments" include three things. 1) A load duration factor. 2) A safety factor 3) A 5% offset to adjust for the high COV in wood. So, just like you have large differences between E and Emin, you'll have a big difference between these values.

I know of some engineers that use the woodhandbook to find "equivalent" species that they are more used to working with. So, if IPE is supposedly stronger than doug-fir, they would use doug-fir values. This isn't quite right as it doesn't take into account a difference in COV, but it is something. They just up their factor of safety, I guess.

 

[HeavyCivil]

So you're saying doug-fir will fail at 12,400 psi in bending? I'm skeptical.

Load duration factor is something applied by the designer to allowable stresses. Unless we're dealing with dead load, it will only increase an allowable stress.

But anyway, since IPE's ultimate bending strength is higher than the allowable bending stress of A36 steel I'm going to start specifying IPE W-shapes to get LEED points.

"All W-shapes shall be extruded from solid Ipe heartwood grade Fu=22.5ksi"