Which lasts longer- RR ties vs. PT timbers
I am building some Timbered steps on a sloped pathway, basically following this outline I found online: http://www.sustland.umn.edu/implement/steps.html
Since the tails of each u-shaped step will be buried into the slope, it was recommended that I use PT timbers rated for direct burial. These are not available locally, and will be very expensive if I special order them.
alternately, PT timbers rated for “ground contact” are 25% less expensive, and available in stock.
The PT timbers im looking at are the MicroPro treated brand.
Since we live in an area rich with railroad ties, I can get these for free or very cheap, and many of the ‘locals’ say they will outlast any PT timbers anyway.
So my questions are which is the safest product to work with and to put in the ground, and which is going to have the longest life span in this application?
any thoughts appreciated!
In my opinion-use the better PT-rated for burial.
RR ties are a pain to work with-dirty, heavy, very hard to drill and cut. Ends in the ground are where they punk out. I have seen them deteriorate-but, these were probably salvaged and had a life span that might have been nearing their end.
The ground contact rated PT will not hold up. The ends will wick moisture even if coated-the PT isn't as deep and many times they are not made out of Yellow Pine.
You MUST treat the ends-I've used preservative and tar to seal the cut ends not exposed.
The main problem is that the RR ties you get are not new, they're something like 50 years old already, and nearing end of life. They were removed because they were going punk and were not longer sound enough for RR use.
Any of them are safe to put in the ground.....the longest lasting will be the most expensive. If you are going to bury them then it would make sense to me to use a grade designed for just that.