Child Item

How to re-harden rotten wood?

Good afternoon everyone. I have a 7 sleeper high treated pine sleeper retaining wall, which I have just cleaned and stained most of, except the bottom sleepers. I found the bottom row were all starting to rot. I was thinking to use Earl's Wood Hardener to re-harden the affected sleepers but the timber needs to be dry before use, and since my sleepers are partly below ground level I don't know whether they will ever dry, since it is also on the south side of the wall. Even though we have had a lot of dry weather in Vic, it is still damp at the bottom. Can anyone give me some suggestions??

Find more posts tagged with

Tools and Materials

Repairing

Landscaping

Fencing and Screening

Comments

EricL

Hi @ChrisNoor

I'm sorry to be the bearer of bad news, but the wood hardener is not going to work on your sleeper. The sleeper at the very bottom has absorbed a great deal of moisture through the years, and odds are it has begun to rot. The repair procedure is to replace the bottom sleeper with a new one. Generally speaking, the bottom sleeper will need to be dug out, but if it appears to be too difficult, I suggest engaging the services of a retaining wall specialist.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

ChrisNoor

https://www.workshop.bunnings.com.au/discussion/comment/52568#Comment_52568

Yes that certainly is bad news. I was worried about that. Thank you anyway,

Nailbag

Hi @ChrisNoor

To remove the bottom row only, you will need a reciprocating saw, which you can borrow, hire or buy. If you know a plumber or builder, they will have one for sure. If not and if you're not likely to use it again compare hire cost vs buying something like this corded model. If you're already in a battery tool system check out their models. Just be aware you will chew through the battery charge. These saws are also ideal to prune tree branches etc. which is also the blade to use for this application as its course teeth won't gum up with damp sawdust and dirt. But will dull it.

Dig the soil away from the bottom row.
Then drill near the top and near each end of the sleepers with a 25mm spade bit.
Insert the blade around half depth so your not digging to much in to the soil, and make the vertical cuts. The soil behind will be very compacted so it won't collapse when the sleeper falls away.
Dig behind each remaining offcuts behind the vertical supports to remove them.
Replace with new sleepers shorter than original. This allows you to insert one end then push in and slide along the other end as per image.
Drill an 8mm pilot hole through the vertical sleepers and drive a suitably length (depends on your sleeper thickness) batten/bugel screws to secure the new sleepers into place.

Nailbag

Screenshot 2025-05-23 at 6.49.58 am.png

Dave-1

https://www.workshop.bunnings.com.au/discussion/comment/52572#Comment_52572

Good Morning @ChrisNoor

I must say I like @Nailbag's solution, It just depends on how deep the bottom sleeper/sleepers may be, definently worth a try.

Id also check all the rest of the sleepers, especially the lower ones plus the posts themselves as I have found when there is one there may be more 😕

If you find a resonable quantity of lower sleepers that need to be replaced then it would push me towards considering replacing the wall (as much as its a pain) A temorary fix will work but the issue of water logged timber is still there. You could install a dish drain in front of the wall to help make sure water that is seeping through can run away as well.

Dave

ChrisNoor

https://www.workshop.bunnings.com.au/discussion/comment/52572#Comment_52572

Thank you.for your help and encouragement. Here's a question though,. (Probably a silly one), do you think it would it be possible (probably not) to knock the sleepers down from the top into the bottom space and add one to the top?

I actually have a corded reciprocating saw.

Nailbag

https://www.workshop.bunnings.com.au/discussion/comment/88465#Comment_88465

Hi @ChrisNoor

Interesting idea but nope. Realistic options is to dig the soil out from behind and replace all damaged sleepers or build a new one directly in front repurposing any salvagable ones. But using gal uprights and lining the back of the sleepers with builders plastic to extend life etc.

Nailbag

Dave-1

https://www.workshop.bunnings.com.au/discussion/comment/88465#Comment_88465

Afternoon @ChrisNoor

Id say a nope to that one as well 🙂 Apart from screws + soil being in the way I think t would ad dmore work for yourself. Didg it out and repair and replace what is needed plus install a decent drainage system at the bottom rear of the wall is the one Id go for 🙂 If the posts are ok, work your way along the walland replace a section at a time, if the posts nee dchanging then Id remove the wall and redo just to make sure its straight.

Dave

Child Item