# Using logs to fill in berms?



## Blue Sugar (Feb 16, 2004)

I want to put some berms on a trail I'm building. I have some good dirt to use from the benching operation but possibly not enough to build the berms. I'd like to avoid mining soil and instead use something to help fill in the berm. Rocks are best but I don't have any rocks to work with. I do have a good supply of fallen oak limbs. Anyone ever use wood to help fill in a berm? Any problems with doing this, advice on how to do it? I've seen it done before. 

Thanks


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## radair (Dec 19, 2002)

Personally I think it's preferable to build something to last, and wood generally does not. You can get away with it on the short term but expect your berms will be 'clapped out' and flatten over time.


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## aero901 (Apr 11, 2012)

We don't have native rocks either and build our berms using oak logs (>8" diam.) as retaining walls to hold soil in place. This cuts the amount of dirt needed by roughly half and the logs will last ~6 years before needing replacement (Midwest climate). Peel off the bark and they might last a little longer. If you have existing trail on steep cross slopes it's pretty easy to mine soil from the backslope. I'd skip putting the logs in the middle of the berm because it will be harder to repair once they do rot.


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## mtbty (Jun 15, 2012)

If your planning on the trail being around a while and it's going to be high use don't use wood fill. Dirt doesn't stick to wood well and it will sluff off in year or two, then all you got is a slick bummer rail in the turn. 

We rip out log fill all the time for the reason above and replace with dirt. Things i've rebuild with just dirt three of four year ago are doing just fine but i've got a long list of bummer rails to fix still.


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## Blue Sugar (Feb 16, 2004)

Maybe I'm over thinking it but even if the logs do rot, which they will, won't the material remain there?


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## zrm (Oct 11, 2006)

Blue Sugar said:


> Maybe I'm over thinking it but even if the logs do rot, which they will, won't the material remain there?


No. Rotting by definition means material is being removed by chemical process and/or by insects. It either turns to gas or is eaten by bugs. If your berm is 50% log by volume, expect to loose a portion of that every year until - depending on local conditions - it is all gone.


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## cerebroside (Jun 25, 2011)

aero901 said:


> We don't have native rocks either and build our berms using oak logs (>8" diam.) as retaining walls to hold soil in place. This cuts the amount of dirt needed by roughly half and the logs will last ~6 years before needing replacement (Midwest climate). Peel off the bark and they might last a little longer. If you have existing trail on steep cross slopes it's pretty easy to mine soil from the backslope. I'd skip putting the logs in the middle of the berm because it will be harder to repair once they do rot.


+1 on this. We use a lot of wood where I build because the site is largely gravel or very sandy. When I build a berm I usually back it with a large log that is staked in place. This just retains the dirt and ideally isn't directly under the tread.
If you peel the bark off the logs and use the largest possible they can last a long time, though I imagine this is very site dependent. A lot of the stuff built this way by previous builders has been there a long time (well over 5 years) without any need for replacement. The logs can also get pretty rotten without affecting the integrity of the berm, since you aren't riding directly on them.


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## cmc4130 (Jan 30, 2008)

I admit, I have done logs to accelerate the process. We did this berm 5 years ago.



















Several years later, with zero maintenance:










But, yeah, eventually the dirt will wear down and the logs will show through. Then people will complain. It's not something that can't be fixed with some wheelbarrow loads for another several years. Definitely don't bother carrying logs miles through the woods or anything. That time would be better used simply digging more dirt. But, if the dirt is really tough to dig in your area, and you have a ton of logs everywhere, then sure, why the hell not.

Yeah, if you can, just use dirt only. :thumbsup:


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## cjohnson (Jul 14, 2004)

Been there, done that, rebuilt it.


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## bitflogger (Jan 12, 2004)

I'll might still use wood or logs where the result will be OK or easily fortified if or when the wood rots. That's more often a roller than a berm.

It's worth looking at the tread in cmc4130's post. At times I see berms made where bike tires will never really touch the high side, and other times so, sometimes a bit of a berm doesn't need a lot of support, sometimes yeah.

If I berm doesn't need to be big I've used wood to start holding it, but not where rotting will make it collapse.

Full disclosure: A mini excavator in our community has changed a lot of my thinking because berms can be made better.

One other problem with berms, time and materials is people will build them where and when they don't make a lot of sense. I was guilty of this before I know how to pump a bike. Now I can be the evil spoiler of fun when I try and tell people they're wasting their time. Really make sure you're putting in effort where a berm will work if you're not looking at or listening to your mini ex.


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## Walt Dizzy (Aug 18, 2003)

Blue Sugar said:


> I want to put some berms on a trail I'm building. I have some good dirt to use from the benching operation but possibly not enough to build the berms. I'd like to avoid mining soil and instead use something to help fill in the berm. Rocks are best but I don't have any rocks to work with. I do have a good supply of fallen oak limbs. Anyone ever use wood to help fill in a berm? Any problems with doing this, advice on how to do it? I've seen it done before.
> 
> Thanks


The question I'd be asking myself is, how is this going to end well? There is no question that the logs are going to rot eventually. If the rest of the trail is poorly laid out enough that it will all go bad in the same time frame, I guess you could justify it that way.

The best way to get more fill, IMO is to save the spoil from cutting bench and cart it to where you need it. I don't know your situation, but most of our trail was scratched out on the hillsides with the minimum amount of effort required. It's an excellent use of time to go back and cut the benches properly, and use the spoil where you need it. Yes, this is more work now, but you will have the satisfaction of doing the work right and not pretending you aren't saddling your successor with a god-awful maintenance headache.

Walt


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## cmc4130 (Jan 30, 2008)

Daggers' trails:


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