I wouldn’t recommend/suggest that type of “retaining wall” to anyone. Don’t you have a graphic of a real retaining wall - PIP concrete or CMU?
Every time I find these landscape timber walls, 75% of them are hollow and infested with Carpenter Ants.
I like to see masonry (with weeps) when it comes to retaining grading.
It’s a cool graphic. But a RR tie wall at that height most definitely needs engineering. In a previous life I built plenty of these but would never go above 4 feet unless there was some engineering money in the job. Above 4 feet various concrete products are jore cost effective. If you’re trying to make a more universally useful graphic make it lower and leave some options for materials.
We created that graphic because so many of these fail.
This image is meant to allow inspectors to show a client how a failed wall should have been anchored and protected from hydrostatic pressure.
If you look at past suppliers of these types of images, many images appear to be created to educate home inspectors. At the top of our priority list is supplying images that inspectors will find useful in educating their clients.
That was actually my point Kenton. Anytime railroad ties are use for retaining purposes, they should be called out as a potential hazard - regardless of how they are anchored or protected. It’s only a matter of time before they fail.
I say, if you’re an inspector and you use this graphic to show how the wall should be constructed, you should expect to be held partially responsible when it fails.
As an association, we should not be promoting the “proper installation” of an unacceptable system. Will we next be creating a graphic showing the proper installation of an S-trap on your DWV system?
When inspectors are confronted with the problem of having to explain failure of questionable systems to clients with the explanation covering things that clients can’t see, we’re trying to provide help. Septic systems are another example, or the forces acting on a home foundation.
Maybe a better image would be one which shows the different forces acting upon a retaining wall… gravity, hydrostatic pressure soil movement, etc.
Jeff, I think you underestimate the adhesion properties of creosote.
But I do agree with your post. Retaining walls are ENGINEERED, stacking RR ties is not engineering in any way shape or form.
Though I do appreciate INACI’s effort and a special thank you to Kenton for all his work.
That particular graphic is missing weep holes. With no drainage, a poured concrete wall failure is imminent.
I’d like to see additional retaining wall graphics depicting failures.
It did have a perimeter drain but we’re adding weep holes to it.
Locally, RR ties are no longer allowed to be used in landscaping of any type due to leaching creosote into the ground. I wonder how they get around all those RR ties being used by the Rail system leaching into the ground and have for eons.
I was just in Mississippi last week for Mother’s Day and noticed some RR ties laying along side some tracks and mentioned this and the individual said the same prohibitions exists there as well. Personally, I used RR ties in the past for landscaping and they lasted about 20 years before the bugs and water destroyed them. Landscape timbers lasts about 7 years and actually have the lowest rating for preservation for treated lumber.
P.S. The graphic is helpful in showing customers what a typical retaining wall components should look like. I know of several different designs as I am sure others are. I still see numerous walls and hold backs made from RR ties and most of them are failing due to poor design or installation.
Irene washed out a 25 year old RR tie wall and driveway at nearby condos.
No one inspected it, nor did an assessment which resulted in $500k repairs.
If I can dig out the photo, I will post it.