# Retaining wall timber posts are splitting



## andy434 (Oct 8, 2015)

Hi, I have a problem with the treated pine H4 posts I used with the retaining wall that I built. These have only been in for about a month and already they are splitting. Some are splitting straight down the middle

Is there a treatment or something I can do to prevent this and repair the ones I have done already? They are all cemented in.

Cheers


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## gregzoll (Dec 25, 2006)

You will always get splits with wood. You need to use landscaping blocks for the retaining wall, not cheap pressure treated lumber.


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## andy434 (Oct 8, 2015)

Thanks for the reply gregzoll. That is a little too late now as the retaining wall is finished and I have 12 posts cemented in and 5 of these have splits.

The guys at the hardware store said it'd be fine before I started and the videos I watched before commencing pretty much reenforced what they said at the hardware store. So I went with that.

What I need to know is, is there anything I can do to repair the posts I have or do i leave them?


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## oh'mike (Sep 18, 2009)

The splits are called 'heart checks' That happens a lot with PT wood because it is so wet when purchased--

They do not affect the strength of the structure as much as you might think--
Not good in 2x4 and 2x6---and will hasten the rotting of the wood when buried--or encased in concrete.

Not much you can do now---just remember this for the next time---


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## ZTMAN (Feb 19, 2015)

Retaining wall? How big is the wall. In the pic you posted it looks like a curb to retain landscaping rock


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## joecaption (Nov 30, 2011)

2 X's are not even rated for below grade use, says so right on the tag on the ends when you bought them.


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## ZZZZZ (Oct 1, 2014)

You can try to reinforce the split boards by nailing a 2x piece vertically across the splits, to tie the upper and lower pieces together. May not help much, but it might stop them from splitting completely in half..


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## ron45 (Feb 25, 2014)

I can't believe you put bolts in it.


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## gregzoll (Dec 25, 2006)

oh'mike said:


> The splits are called 'heart checks' That happens a lot with PT wood because it is so wet when purchased--


I still have the 1x6's sitting in my garage for capping off the railings on my deck. It helps to pull any moisture in the boards when they are either wet off of the stack, or still a little moist from delivery.

I wished that I had done that to the 2x6's that were used for my deck boards. A bunch of them are now starting to show small splits from drying out after installed.


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## andy434 (Oct 8, 2015)

Firstly, why wouldn't I have used bolts? What's wrong with that? Was there another way? It is my first attempt at a timber retaining wall. Having a go at me for what I used is not helpful and it isn't what I am on here for. I am inexperienced. All concidering I did what I thought was right and I think, I didn't do a bad job.

Thanks ZZZZZ. I thought about putting bolts through the sides to pull the post together. Any thoughts?

I've included pics of the retaining wall.


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## ZTMAN (Feb 19, 2015)

You have carriage bolts on each side of the 2x. That split in the wood is not going anywhere. I would just fill it with epoxy if it bothers you. I would suspect that crack was caused by over tightening the carriage bolts


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## joecaption (Nov 30, 2011)

Not sure what the big deal is ether with using bolts, it's done all the time when decks, docks, carports, pole barns, Pergola's.
You will find those 2 X's below grade rotting out though.
It should have been 4 X 4's or 4 X 6's.


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## Daniel Holzman (Mar 10, 2009)

The only problem with the carriage bolts is that they appear to be standard steel, not galvanized, which is a problem in contact with PT lumber. I probably would have used hot dipped galvanized hex head bolts, not carriage bolts,since you may need to remove one someday, and there is nothing to grip on the dome end of a carriage bolt.

The splits in the wood are typical of PT lumber when it dries, not much you can do about it, and as previously noted, will not reduce strength much. Besides, that is a low retaining wall, so likely no problem at all, other than appearance.

There are some types of PT lumber rated for direct contact with ground, they are expensive and not too easy to find. Most PT lumber is rated for outdoor exposure only, not ground contact. All this means is that they lumber will rot after perhaps ten years, maybe it will go twenty if you are fortunate, so at that point you can replace the wall. When and if you need to replace the wall, you may want to consider concrete segmental block, in my opinion easier to install than lumber, lasts essentially forever, and very cost competitive.


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## andy434 (Oct 8, 2015)

Thanks for the reassurance ZTMAN. I was worried about the integritty of the structure.

I didn't want to use the hex bolts Daniel, as I thought the ones I used looked better with the whole being flush thing. Makes sense what you say though. I will remember this for next time. You're right. It was a bugger of a job. I have done a block retaining wall before and it was easy after doing the base.

The carriage bolts I used are coated green. Said on the box that they are intended for outdoor timber use. Didn't think the galvanised bolt would be suitable. 

Thanks Joecaption for the tip.

I'll remember for next time.


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## JustScrewIt (Mar 14, 2015)

I'm gunna echo Joecaption about the carriage bolts. I see them used all the time in park benches, jungle gyms, and other public-use structures. I can't think of any reason why OP would ever need to remove the bolts cleanly. I think the fact that he cemented the posts in the ground and filled the area up with several thousand pounds of rock indicates that it was a conscious decision to NOT make it easy to come apart. In any case, I think it came out pretty darn nice! Simple but classy. Worse comes to worse, OP could just get a quart of Dap's Plastic Wood putty. Personally, I like a little bit of an aged, rustic look, especially when it's complemented with the more modern 'floating' seating area. Adds character!


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## ZZZZZ (Oct 1, 2014)

OP Andy, can you tell us about that rainwater collection system that you've got there? How big are thanks? How much water do you collect? How is it used?

Thanks.


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## JustScrewIt (Mar 14, 2015)

@Z -- we got 55 gallon rain barrels around the building at work. It rained very briefly over about a week ago. Not torrential or anything, just a light sprinkle. All the barrels went from bone dry to overflowing within an hour. 

Question for OP: Do you have a regular hose bib attached to yours? If so, does it have a decent flow rate? Because on the barrels we have at work, the water just trickles out with the bib fully open. The barrels have a screen on the top where the gutter feeds it so the bib isn't obstructed (to my knowledge...) I was thinking maybe it needs a carb or something to even out the pressure? I would've thought the water would come pouring out with all the weight, but no...


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## SeniorSitizen (Sep 10, 2012)

andy434 said:


> Thanks for the reply gregzoll. That is a little too late now as the retaining wall is finished and I have 12 posts cemented in and 5 of these have splits.
> 
> The guys at the hardware store said it'd be fine before I started and the videos I watched before commencing pretty much reenforced what they said at the hardware store. So I went with that.
> 
> What I need to know is, is there anything I can do to repair the posts I have or do i leave them?


The hardware folks and the vid generating people, bless their pea picken hearts, were hired because they know how to operate a computer and that's about it.

If the lumber you purchased was moisture tested we would find a percent of moisture somewhere upwards of 25 percent in my estimation. 

So why did the posts choose to split in the most unsightly location at the visible end? They split there because there are 2 exposed edge surfaces to dry plus the end which caused dimensional stress of the width. ie, the advanced drying there pulled it apart. The two face surfaces of the wood didn't matter much concerning drying rate. If you were to remove a post you would probably find the split stopped not too far below soil surface because of soil moisture.

To avoid this the lumber would need to be an estimated 6-8 percent moisture when installed and then if moisture was increased from exposure it may bow between bolts.

In my opinion this is expected in our modern high speed society and it looks just fine and very normal.


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## nwhomesteader (Sep 11, 2015)

There's almost always going to be one person with some scathing comment even in a diy help type forum, forget about it. The wall looks good and I'm sure will last quite a while. When it starts to rot in the future, just replace it with retaining wall blocks and you'll never have to worry about it again. 

As far as the splits, it looks like the wood was still pretty wet when sunk in concrete and the concrete curing sucked the moisture from the wood causing it to crack. It's not going to do anything to the structural integrity of the wall though. 

Looks nice with those bolts. Good job.

Sent from my SCH-I545 using Tapatalk


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## andy434 (Oct 8, 2015)

Thanks JustScrewIt. I didn't think it looked too bad. It's an outdoor area for the man cave inside. The plastic wood putty is a good idea. Thanks for the compliments.


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## andy434 (Oct 8, 2015)

ZZZZZ said:


> OP Andy, can you tell us about that rainwater collection system that you've got there? How big are thanks? How much water do you collect? How is it used?
> 
> Thanks.


The rainwater tanks hold 3000 litres. It is a requirement that we have water tanks off our sheds. (depending how big the shed is though) Council requirements. The water in these tanks will be used for washing the cars, gardening etc.


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## andy434 (Oct 8, 2015)

JustScrewIt said:


> @Z -- we got 55 gallon rain barrels around the building at work. It rained very briefly over about a week ago. Not torrential or anything, just a light sprinkle. All the barrels went from bone dry to overflowing within an hour.
> 
> Question for OP: Do you have a regular hose bib attached to yours? If so, does it have a decent flow rate? Because on the barrels we have at work, the water just trickles out with the bib fully open. The barrels have a screen on the top where the gutter feeds it so the bib isn't obstructed (to my knowledge...) I was thinking maybe it needs a carb or something to even out the pressure? I would've thought the water would come pouring out with all the weight, but no...


I've just connected a water pump to the tank with tap. Water pressure is strong. It wouldn't be though without the pump.


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## JustScrewIt (Mar 14, 2015)

andy434 said:


> Thanks JustScrewIt. I didn't think it looked too bad. It's an outdoor area for the man cave inside. The plastic wood putty is a good idea. Thanks for the compliments.


That's one helluva man cave. Tim The Toolman Taylor would be proud! :thumbup:


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