Hardwood floor joists

[D6c]

I'm thinking of building a mezzanine across the back of my shop for storage.  Probably be 10-12 ft wide across the 38' wide end of the building.

I have a bunch of ash logs that I could saw 2x8 or 2x10  joists out of. It'll take about 30 of them on 16" centers.
Would the ash be a reasonable wood to use?
I see I can get joist hangers for full dimension rough sawn lumber from Menards.  I'd probably still use an LVL beam across the front with two supports.

Sound like a reasonable plan?

[etd66ss]

You could use the calculator:

https://awc.org/codes-standards/calculators-software/maximum-span-calculator-for-wood-joists-and-rafters---full-page

Unfortunately I don't see ash as a selectable NDS option.

[moodnacreek]

 Might be 2 problems; ash is never recommend because of insects boring and hardwood under load sags more than softwood. I suppose if borated the first problem would go away. The stuff should be dried 2 years also.

[Magicman]

During the past 2 months I have sawn well over 100 Red Oak floor & ceiling joist and rafters.

[DanMc]

Over the years of buying log-length firewood, I have observed that when my log pile sits for a number of years out in the weather, the white pine, maple and even red oak will get punky at about the same rate.  The white ash just sits there.  The bark peels off and the logs don't do anything.  I have yet to see a punky ash log.  My piles get cut up by 4 years, so that's the time limit.  I'm not talking about logs sitting in dirt, these are logs within the pile.  I haven't had any ash logs in the dirt, so I can't say anything about that.  

[Den-Den]

If the ash is good quality when you saw it, it will be fine as long as it stays dry.  Clear straight grain ash is very strong, knotty or with grain run-out may fail in a dramatic way.

[Kodiakmac]

(1) The post and beam barn on our family farm where I grew up has 12" x 8" x 44' ash stringers over the stable.  They are as sound as the day they were hewn in 1896.  In the 44 ft. they are supported at both ends and at 2 other locations.  They supported tons and tons of hay with no sagging issues.

(2) My dad and I built 2 haywagon racks back in the early 70s.  We used 4" x 10" x 18' ash for the main beams and 4" x 4" ash for the deck supports.  Up until 5 years ago, my brother was still using one of those racks.

[etd66ss]

(1) The post and beam barn on our family farm where I grew up has 12" x 8" x 44' ash stringers over the stable.  They are as sound as the day they were hewn in 1896.  In the 44 ft. they are supported at both ends and at 2 other locations.  They supported tons and tons of hay with no sagging issues.

(2) My dad and I built 2 haywagon racks back in the early 70s.  We used 4" x 10" x 18' ash for the main beams and 4" x 4" ash for the deck supports.  Up until 5 years ago, my brother was still using one of those racks.

I wonder why NDS doesn't list design values for Ash? There must be a reason. I have so many dead ash trees from the borer, would be nice to utilize them for lumber.

[Kodiakmac]

. I have so many dead ash trees from the borer, would be nice to utilize them for lumber.

Dead trees would be a totally different story.

A friend bought a pre-fabbed spruce shed from a certain community in upstate NY.  After he had it delivered he asked me to move it from one side of his yard to the other.  So I went over with my skidder, hooked a chain around each of the skids, put a brace between the skid ends, and started pulling.  When the chains tensioned up one of them put a wee bit of pressure on the bottom of one of the pieces of vertical siding.

POP!  A chunk broke of the bottom.  I got off to have a look.  The whole shed was built out of dead spruce...it just like that sponge toffee we liked when we were kids.  Absolutely no strength.  

Now I know I'm talking about spruce - and you're talking about ash - but I'm willing to bet a dollar that lumber from diseased ash has a lot less strength than lumber from a green tree.

[beenthere]

but I'm willing to bet a dollar that lumber from diseased ash has a lot less strength than lumber from a green tree.

Curious to what you think happens to the wood of the ash tree killed by the ash borer that would cause loss of strength. Any ideas?

[Kodiakmac]

Curious to what you think happens to the wood of the ash tree killed by the ash borer that would cause loss of strength. Any ideas?

Nope.  At least nothing scientific.  I'm just thinking it would be something like the spruce killed by budworm.
I can't think of any dead tree that I've ever cut - and I've cut more than one or two - that had the strength of its living counterpart.
Buddy used to run a flooring business.  One of the suppliers he dealt with started shipping him ash that had been milled from dead trees.  Not the same stuff at all as the boards cut from good trees.

There seems to be a relatively short period while the tree is dying - as opposed to dead - that the lumber seems to be pretty good.

[Oddman]

Been logging borer killed ash at our place for the past year. Most trees still had some leaves this past summer. Theyr still sound.

[etd66ss]

. I have so many dead ash trees from the borer, would be nice to utilize them for lumber.

Dead trees would be a totally different story.

A friend bought a pre-fabbed spruce shed from a certain community in upstate NY.  After he had it delivered he asked me to move it from one side of his yard to the other.  So I went over with my skidder, hooked a chain around each of the skids, put a brace between the skid ends, and started pulling.  When the chains tensioned up one of them put a wee bit of pressure on the bottom of one of the pieces of vertical siding.

POP!  A chunk broke of the bottom.  I got off to have a look.  The whole shed was built out of dead spruce...it just like that sponge toffee we liked when we were kids.  Absolutely no strength.  

Now I know I'm talking about spruce - and you're talking about ash - but I'm willing to bet a dollar that lumber from diseased ash has a lot less strength than lumber from a green tree.

I know quite a bit about spruce. When I cleared my land for my homestead, I took down a lot of hardwoods that protected a large spruce stand from wind. I lost 100's of spruce to wind over the subsequent years. I tried to log them as quickly as possible and get them to my brothers mill, but inevitably many if not most sat too long before they were milled. It doesn't take long for them to get punky.

As far as the Ash borer, I'm pretty sure they just killed the trees by eating the cambium. I don't think they affect the structural integrity of the wood.

I do know that the Silver Maple I have had sawn got insect infected very quickly. I used it for shelving in a storage container and for years there was new piles of sawdust from critters tunneling in it.  This is why I am building a solar kiln, so hopefully I can make better use of the trees that I lose or harvest.



 


 

[Kodiakmac]

Most trees still had some leaves this past summer. Theyr still sound.

My experience too.  I mark the dying in the late summer and log them out that winter.  

[wisconsitom]

Don't know exactly why either, but as hard and strong as ash wood is when derived from living trees, it's just that weak and prone to failure once killed by borers.  Tree stand hunters got to avoid eab ash.

[moodnacreek]

Ash lumber from bad logs can fool you. It has a way of deteriorating you may not notice. Ash has pitch like conifers and I think this keeps it looking good when it is not. The best test is to wack a board with a hammer and see if it breaks. A pallet maker explained this to me a long time ago and with all the dead ash around now you need to consider this if you do ash. People tell me all the time how good there old logs are but they have never sawed for a living.

[Don P]

I've been trying to make sense of these comments and I think Doug just answered it. Mechanical properties, strength, drops dramatically due to decay before we can visually detect it. Often I can see a slightly bleached out look in other species of wood that is a telltale but bear in mind that by the time I have a visual clue, that wood is already in trouble. Ash to my eye already looks bleached, it isn't going to readily give even that clue. By the time we know something is going wrong it is already brashy, Doug's "whack it" and see if it breaks long or short. Another test is the pick test. With an awl, stick in and pry up some long fiber. Did it pry up and pull a long fiber or break short and weak over the pick, that would be decay. Anyway, just thoughts.

There are 2 here that the only way I'm dropping them is from inside the dozer, widowmakers.

For design properties, I suspect it had higher uses than dimensional framing and wasn't commercially important enough to make the book. About 100 years ago the FPL was looking for the next tree for auto frames, we were depleting the ash stock at the time that rapidly. Excellent impact resistance for one. Anyway, look in the wood handbook at the ultimate properties and look for similar ring porous woods with similar strengths. This is not "correct", but better than a poke in the eye. Mixed oak is not far off if we are excluding black ash.

[Clark]

but I'm willing to bet a dollar that lumber from diseased ash has a lot less strength than lumber from a green tree.

Curious to what you think happens to the wood of the ash tree killed by the ash borer that would cause loss of strength. Any ideas?

As someone who is involved in a lot of urban ash removal I can assure you that dead (beetle killed) ash is notably weaker than living ash. The rule of thumb being bandied about is a dead, 5" diameter ash limb has the same strength as a live, 1" diameter ash limb.

I think the reason for this is the fungal spore load that is transferred by beetles, through the bark and straight to the wood. Multiply that by several thousand beetles on a mature tree and the fungus quickly invades all parts of the tree.

Clark

[beenthere]

Interesting.
Any research being done that you are aware of at UMn or USFS?

[Clark]

beenthere - Here is one that I was able to supply some samples for:

https://experts.umn.edu/en/publications/fungi-associated-with-galleries-of-the-emerald-ash-borer

While it hasn't been proven that EAB are the source for decay causing fungus in dead ash or that conclusion is almost a given. Whether the fungus affects wood strength differently in EAB-killled ash vs. cut trees has yet to be proven but again, seems very likely.

Clark

[Don P]

These are from Clark's paper. 

Fungi in the Basidiomycota were nearly all wood decay causing fungi and many were species of pioneer colonizing genera including Sistotrema, Irpex, Peniophora, Phlebia and Ganoderma. Some of these fungi seriously affect urban trees, having the potential to cause rapid wood decay resulting in hazardous tree situations.

Infection may occur from spores entering through wounds, or they may be already be present as latent endophytes and perform their associated functions once insect attack has taken place (Parfitt et al., 2010). Canker fungi likely invade areas where larvae have wounded phloem and xylem tissue. These fungi may have the potential to attack healthy tissue, potentially enlarging the affected area by the EAB galleries and causing additional necrosis. Some decay fungi are early colonizers of wood and rapidly colonize wounded tissue and cause degradation

[moodnacreek]

Trees can be sick and look healthy, fully leafed out. This can go on for years. In the case of open grown, big top, heavy branches, those branches can fall off on a calm day. If the tree is tall, small top and protected in the woods from wind nobody but an expert knows.

[Don P]

After wasting lots of time only to cull stuff further up the chain, live trees might be sawlogs, dead trees are firewood.

[Sod saw]

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The original discussion was about using Ash for building part of a floor.

We once had a barn (early 1800's) that had beams as many barns did back then.  Some of those were Ash.

Some of the more recent timber frame books talk about using Ash in some of these construction projects.

I have not been able to locate Ash in any tables that spell out how to design proper strengths (read sizes) for the use of Ash.  Without those tables, I find it difficult to know how much an Ash member would be able to handle a given load.  Is Ash used in timber frame buildings today?  Inspected?

Or did I overlook the tables?    It doesn't take much to confuse me.

So. . .  back to that original discussion.       How will the size of those Ash joists be determined?  How far apart will they be and how long of a span can those Ash joist be considered safe?

[Don P]

I would start by calling NeLma.

The correct procedure if NeLma has nothing is to hire them to create and submit design values through the ALSC where the proposal is reviewed by the FPL and others, etc,etc. Norway Spruce in the US has just gone through that process and now has a published set of design values.

At the single house level the building code alternative methods and materials clause may work;

A BO may be comfortable with a letter from an engineer stating the the wood is at least equivalent to one of the more common species.

I've seen an engineer get approval by using the procedures in ASTM D245 to create an allowable set of design values for an unlisted species. Those would require prior approval of the building official.