How to repair this rotting timber retaining wall?

[j3mesf1]

Hi all. I've noticed a run of horizontal sleepers in our retaining wall is rotting badly and need to be rectified quite soon. I'm not sure how this was prepared as it was done by the previous owner but we do have some water pooling in the area above which is likely the root cause. 

I'm unsure as to the best course of action to solve this. Given the rear nesting design I don't think removing and replacing the rotting sleepers is going to be possible. I've thought about installing uprights in the middle between each run and installing a second row of sleepers maybe two high in front of this, ultimately leaving the current one alone.

The existing uprights seem ok, for now. I'm likely going to install agg pipe above the wall to better drain water away and that may extend the life of existing sleepers.

Any advice is appreciated before I tackle this challenge.

 

 

[Dave-1]

Morning @j3mesf1 

Remove all the soil from the segmant all the way through to the other side, it will save effort overall by just trying to remove what you need to to get a tool in there. The screws may be rusted so another option is to use a metal cutting tool and cut the screw between the post and the rail.

Ozito PXC 18V Cordless Multi Function Tool PXMFTS-018 - Skin Only 

Dave

[MitchellMc]

Another option @j3mesf1, is a reciprocating saw with a long metal cutting blade.

You'll need to lever out the sleeper out just enough to slip the blade between it and the post.

Mitchell

[j3mesf1]

Yep have thought of that and ordered a long multi tool blade to try and get in.

I'm quietly optimistic if I can deal with the screws it'll be a manageable task.

Thanks all

[Nailbag]

Hi @j3mesf1 just checking it’s a reciprocating blade you’re getting not a “multitool” one? You will chew through them even using the best hard metal cutting blades through them at great expense. 

The blade @MitchellMc recommended will go though wood and hard metals countless times and a great all-rounder blade to have.  Where possible Just mix up where on the blade teeth are doing the work so not to put all the wear on just them. 

When cutting just nails and large screws I tend to use dedicated metal cutting blades as they are thinner, faster and have more flexibility to make flusher cuts. The screws are most likely 8ga gal batten ones common in retaining walls. So you will need the power and blade type to cut them. 

The other benefit of using a recip saw is that you can get pruning blades that might come in handy to trim back any roots pushing up against any of the sleepers 

Nailbag

[j3mesf1]

Thanks @Nailbag 

Yes sorry I used the wrong terminology there.  I'll use the reciprocating saw which should be fine as I can use the space gained by removing the sleeper above it in each row to gain access to them.  The point about the roots is really good too and will for sure be helpful.

[Nailbag]

Glad to hear it @j3mesf1 and you will find that pruning blade also a very safe accessory for pruning tree branches as well. 

One last point regarding the replacement sleepers. The existing ones have smooth faces and beveled edges. So, it’s possible they are Ironwood and not the everyday treated pine which have rough faces and no bevel. It’s also a reddish colour to distinguish the difference as they are also Arsenic-free. @MitchellMc or @EricL will be able to advise availability.

If there is a supply issue, and you own a planer, you could create your own be bevel to standard treated pine sleepers. Otherwise a random orbit sander would do an amicable job, the bevels just won’t be as sharply defined. 

Looking forward to a few updated photos. 

Nailbag. 

[j3mesf1]

Hi again,

Thought I'd update with progress. I've successfully replaced the sleepers in this section after some challenges along the way.

Initially I was hoping to only replace the bottom sleeper but it became evident very quickly that all would need replacing as you'll see in the images.

The combination of roots and moisture made short work of each sleeper but the silver lining was that scrapping them made disassembly a lot easier. I was able to saw down each side to pull them out then using a reciprocating saw, shear the bolts holding the ends in to pull them out.

The largest challenge I faced was that the soil had deformed the sleepers and it was bowed so heavily I had to grade two wheel barrows worth of soil to make it square again for the incoming sleepers. Very painful!

Once done I repacked the agg pipe at the botto with gravel and placed plastic over the top. I hope a combination of this and the heavy painting will help combat future rot better.

Thanks again for the advice, certainly made the process easier.

Only 8 sections remaining....

 

  

 

  

 

[JacobZ]

Hi @j3mesf1,

It's brilliant to see you've made some progress. Hopefully, your experience from this first section makes the rest a little bit easier to manage.

I note that @Terry66 is currently dealing with a similar issue and could certainly benefit from seeing what you've done.

Thank you for sharing.

Jacob

[Dave-1]

Evening @j3mesf1 

Nice work in repairing the wall Worth the effort and now you know its good for another bunch of years

Dave

[Nailbag]

Sensational effort @j3mesf1 Its a big job but well worth the investment for a long term resolution.

Nailbag