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Wood post Cracks 1

Rsayed PE

Rsayed PE

Structural
Jan 9, 2020
23
I designed a deck with 8x8 wood posts in Tampa, FL

the posts are 15 ft apart with deck projection of 13.5’ from the house. Those cracks appeared and started to progress in the past 2 month since the GC installed the posts. I know these maybe a normal checking but i needed an opinion. Some of these columns have checkings in both directions. The column per my design is at %50 capacity (Max) The applied ASD axial load is about 11kips for the 11.5’ columns.

Anything I did wrong here ?
Any ideas on how to repair/remediate ?
 

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Looks like normal checking. How on earth are you getting 11k per column?
 
Last edited:
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Depends on species of lumber used, sealing to keep moisture out. But wood is natural to it will almost always do this with changes in moisture content and sun.
 
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These cracks are normal checking. Nothing to see here. Move along.

Pressure treated southern pine timbers are often "soaking wet" when you get them from the big box store. Sort through a stack of fresh ones and you will notice that they are all quite heavy and you will encounter several that weigh about a ton (exaggerating) . As they dry in the Florida sun, these checks can happen.
 
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Those look like normal checks to me. 8x8 PT SYP gets fairly noticeable checks.
 
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The column size sounds way too big for a deck. Also, the larger the column the higher the probability of checks presence.

100 psf LL for a residential balcony seems a bit excessive. Per ASCE 7 table 4.3-1:

Residential Floor LL = 40 psf
Residential Balcony LL = 40 psf * 1.5 = 60 psf

Two remedies that come to mind, that I would consider:
  • Long screws (stainless steel only as the wood is PT and it is exterior use) to pull the “splitting parts together”
  • Wrap steel collars (stainless steel) that are spaced at reasonably along the column height.
 
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Two remedies that come to mind, that I would consider:
  • Long screws (stainless steel only as the wood is PT and it is exterior use) to pull the “splitting parts together”
  • Wrap steel collars (stainless steel) that are spaced at reasonably along the column height.
Click to expand...
Remedies for what? Checks like these are of no concern, structurally.
 
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From a serviceability standpoint, the checks in the column don't look too good, even when the strength requirement is met.

What about a facade for the columns to hide the checks?
 
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duckhawk said:
What about a facade for the columns to hide the checks?
Click to expand...

Just make sure that, whatever facade system is used, the post can still breath. Based on your photos, I'm guessing that this is a high humidity environment. The last thing that you need is a bunch of moisture getting trapped between the cladding and the post, preventing it from drying out.
 
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I agree with the comments that this is just natural checking of a large sawn lumber column.

But, speaking as someone who's parents experienced this at their house.... I KNOW that a homeowner doesn't want to hear "it's fine". They look at it and think, "This just looks unsightly. Is this going to affect my ability to sell the house in a few years."

I'm not sure I have any permanent solutions to the issue. Lutfi's ideas seem reasonable. But, they might be unsightly as well. I wonder if anyone has experience with epoxy injection for repairing wood checks like this? Fiber wrapping would okay too, but probably waaaay too expensive.
 
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Some 1x PVC trim is your best friend here. It's not cheap, but it looks way better and is the standard for these sorts of applications. @KootK is absolutely right about breathing and drainage - a well meaning contractor can ruin everything with an overzealous application of caulk.
 
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It is probably a coincidence that the checks on the middle column (picture 4) align with the inside edge of the support beam. Could what little load has actually been applied compress the column unevenly and expand the existing checks?
 
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DanKile said:
Could what little load has actually been applied compress the column unevenly and expand the existing checks?
Click to expand...

I see it the same way. Shrinkage + a load arrangement that encourages splitting where you see it.
 
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I would do absolutely nothing to address these totally normal and common checks other than assessing them and arriving at the aforementioned conclusion, but if you are dead set on implementing a completely unnecessary, elective, cosmetic remedy to hide the checks, just wrap the columns with 1x10's and be done with it. Leave an air gap between the 1x10 wrap and the column to promote drainage and drying. It looks like the space above might be finished, so no water should be able to enter the cavity from above. You can also use Hardie plank material for the wrap. It is extremely common in my area for residential porch roofs to be supported by a wood 4x4 with an 8x8 Hardie plank wrap.
 
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gte447f said:
Remedies for what? Checks like these are of no concern, structurally.
Click to expand...
I see this all over the internet and have never understood it
How are checks not a structural concern?
Surely they impact both compression and bending capacity, plus have implications for cross-grain loads e.g. screw fixings in tension
I can understand that "some level of checking can usually be accommodated within standard residential design" but that is not the same as "of no concern, structurally"
 
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Regardless of structure, how did the homeowner accept the disparity between these very "rustic" columns and the other materials seen?

Surely these are temporary while the contractor is waiting for the actual nice columns to arrive.
 
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