We have some retaining walls built using railroad ties. I don't know how
long they've been there, since they were already in place when we moved
in, but they are beginning to look as though it's time to replace them.
If we replace them with new (actually old) railroad ties, how long are
the new ones likely to last? What kind of timber is used for railroad
ties? Anything we can do to make them last longer? -- creosote? The
bottom course is actuually below ground level.

We are thinking seriously about using interlocking concrete blocks
instead. Any thoughts on those?

Perce

"Percival P. Cassidy" wrote in message
...
We have some retaining walls built using railroad ties. I don't know how
long they've been there, since they were already in place when we moved
in, but they are beginning to look as though it's time to replace them. If
we replace them with new (actually old) railroad ties, how long are the
new ones likely to last? What kind of timber is used for railroad ties?
Anything we can do to make them last longer? -- creosote? The bottom
course is actuually below ground level.

We are thinking seriously about using interlocking concrete blocks
instead. Any thoughts on those?

Perce

Around here (Atlanta), they sell different grades of used railroad ties.
I'm sure the better ones last a little longer, but after 15 years, most RR
tie walls start looking pretty ratty, and after 20 years, it would probably
be replacement time.

The interlocking blocks are a good solution depending on how high you want a
wall. Some of the smaller ones they only recommend for 2' or 3' walls.
However, there are bigger, heavier ones that can go substantially higher.
If you hire the work done, this is a fairly expensive option.

Poured concrete is another solution.

"Percival P. Cassidy" wrote in message

We are thinking seriously about using interlocking concrete blocks
instead. Any thoughts on those?

Perce

That is what I'd use. Concrete last longer than wood. Just look at the
Coliseum in Rome. Stone is there, wood is long gone.

Percival P. Cassidy wrote:
We have some retaining walls built using railroad ties. I don't know how
long they've been there, since they were already in place when we moved
in, but they are beginning to look as though it's time to replace them.
If we replace them with new (actually old) railroad ties, how long are
the new ones likely to last? What kind of timber is used for railroad
ties? Anything we can do to make them last longer? -- creosote? The
bottom course is actuually below ground level.

We are thinking seriously about using interlocking concrete blocks
instead. Any thoughts on those?

Perce

There are RR ties and then there are RR ties. They are made from all
kinds of lumber. I have 300 ft of retaining wall built from basically
cull RR ties that is still standing after 20 years but I am surprised.
I have posts that I just pulled after about 20 years in the ground. 3
of 5 were too rotted to reuse (one fell over, rotted at ground level).
2 would still grade #1.

Harry K

Hi Perce:

When I built my 6' tall x 150' long retaining wall 8 years ago, I went
through a similar decision. I ruled out RR ties because of the
creosote. I considered building a wooden wall from 0.6 pcf CCA treated
wood (which I would have had to specially order), but by the time I put
enough material into it (including stainless steel bolts) to hold up
for more than 20 years, it was just as costly to use interlocking
concrete blocks. I chose to use a locally made product, called
Metrostone, which are 20" x 12" x 8" hollow concrete blocks with a
rough face on one side. They weigh 90 lb each, and are dry stacked,
filled with washed gravel, and pinned together with rebar. It took me
about 3 months of weekends to build it. After 8 years, it still looks
like new, and I know it will always be there (barring major earthquake
or armageddon). If I had made it from wood (even RR ties), I'd start
wondering how much longer it would hold up in a few years.

Regards,
John.