When it comes to checking in logs what should I expect?

Question

They started clearing old ash trees from the lot where I work. There was lots of nice wood there so I took a couple pieces. One in particular a piece of green ash (so I was told by the man cutting it down) about 17" in diameter.

I put it in my mudroom outside (for I have no where else to put it really). I don't have the time or the tools right now that I want to process this.

Checking in on my wood (just to admire it I suppose) I noticed after the first day that a crack was appearing through the center of the log. I thought it was odd but wasn't really surprised as that is supposed to happen over time.

It has now been a week and and went to take another look and I was surprised this time to see a lot of radial checking? (I don't know if it has a real term.)

So I am new to processing and milling logs but I would have thought that should have taken longer to happen. That and the checking pattern is not something I have seen before.

Potential contributing factors that I can think of:

• Recently cut
• Stored outdoors but in enclosed space.
• Temperatures are around 0 degrees Celsius (32 Fahrenheit )

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Is this what I should be expecting when working fresh green wood? Should I be working this the second it falls basically to stop this. I'm worried (probably more than I need to be, if any) that if I wait to long its going to crack even more and reduce the yield I can get from this.

Answer 1

Checking in on my wood (just to admire it I suppose) I noticed after the first day that a crack was appearing through the center of the log.

A through-the-centre crack, also a from-the-centre crack, is referred to as a heart shake.

I thought it was odd but wasn't really surprised as that is supposed to happen over time.

Actually it can be almost completely avoided.

When you take green wood, i.e. wood from a tree that was alive when it was cut down, and you don't want to use it straight away the end grain should be sealed ASAP to prevent/minimise cracking due to fast moisture loss.

The best way to seal the end grain if you don't want to use one of the (expensive) commercial sealers is using melted wax. Any candle wax, canning wax or plain old beeswax will work about equally. Note: online it is frequently suggested that a thick coating of 'latex' paint (UK: emulsion) will do for this job but as a rule this type of paint is actually a terrible moisture seal. Wax is many times more effective.

When you don't seal end grain you virtually guarantee some type of cracking on wood of any real size. If you seal end grain properly however you can reduce it by up to 95%; this is on average, sometimes you'll get lucky and no cracks at all will form.

It has now been a week and and went to take another look and I was surprised this time to see a lot of radial checking? (I don't know if it has a real term.)

These are checks, cracks that form along the radius of the log. This is probably the most common type of cracking.

Note that it doesn't have to form when the wood is still a log, even after a board has been separated from the log a radial crack is still a check.

Answer 2

The ends of a log dry out much faster than the center. What to do about it partly depends on the size (length) of the log and your intentions.

The picture makes the log look pretty short, 2-3 ft? For short logs I tend to split them in half. It seems to increase the surface area for releasing moisture from the center where it generally releases slowest.

I've spent years splitting firewood with a maul so I tend to use that tool for such work, when I'm in practice I can 'draw' a line across the log. If as in your case I have a big split happening, I use that as the mark to do the first main split, since it generally makes it easier.

I leave a lot of them that way to dry and it reduces how deep the checking gets.

As Graphus pointed out sealing the ends will reduce checking significantly and while there are many products available to do so, I've found just regular paint can slow it down enough to make it more manageable. Some depends on how much you need to save from the log for your boards. In general you should expect to lose 1 - 2 inches from each end to different damage from drying, unless you seal it immediately (and even there don't think you'll ever get to 100% saved).

Sealing slows down the drying process for the moisture to more evenly leave the log at the same rate, reducing the stresses and splitting/checking that happens.

Ultimately what you want is the log to dry as evenly as possible across as much of the wood as possible. This is why splitting the log can help. The smaller the pieces are the more surface area to volume you get as well, allowing for faster more even drying. It takes much longer for a cup of water to evaporate, than if you spill it across the kitchen floor.