Replies

1. 
   msteinkampf_ | May 31, 2001 01:52am | #1

   *
   Within a few months of repainting a steel porch railing in my own house, I noticed some vertical sections had the paint peeling off the lower ends, with the metal slightly "swollen". I drilled small holes near the affected ends, and out poured some funky brown water. After these sections were repainted, the problem didn't recur. My guess is that water seeps in through a weld, freezes in winter, and damages the pipe. I squirted some WD-40 into the holes after drilling to limit further rusting of the pipe interior.

   Weep holes good.

1. 
   elMarko | May 31, 2001 02:37am | #2

   *I worked in a fab shop where we built several tens of thousands of feet of pipe and tube hand rails. Weep holes were standard issue, but no one ever figured out where the water would come from. The same weldors who welded the rails also welded high pressure pipe and boiler tubes for us, and they didn't leak.

1. 
   Darin_Barber | May 31, 2001 04:22am | #3

   *It is basic pysics. The moisture comes from condensation. The tempurature inside the pipe is different from the outside of the pipe causing condensation in the pipe and water vapour forming clinging to the sides of the pipe and forming pools of water. Just like a cold beer in the hot sun will form water on the bottle or can exterior.

1. 
   xJohn_Sprung | May 31, 2001 04:42am | #4

   *OK, but if you really do seal the pipes closed, the only moisture in there would be the humidity in the air trapped inside, a tiny amount. To have enough to let out thru a weep hole, there'd have to be a way for it to get in.-- J.S.

1. 
   WRose | May 31, 2001 04:16pm | #5

   *Water vapor moving through holes is a two-way street tending toward equilibrium, so any condensation amounts would be small. It more likely has to do with how the pipe rail terminates at the step and temperature changes. When the sun shines on the pipe, the air in the pipe could tend to increase in volume by 5%-10%. When the pipe gets cold, the air volume could shrink by the same amount and suck up air or water or whatever is at the lower termination. So I'd go with weep holes or some kind of air gap between the steel and concrete.

2. 
   xJohn_Sprung | Jun 01, 2001 05:12am | #6

   *Ah, yes. Concrete is porous, so if you had an open end stuck into concrete on a hot day, at night the air pressure inside would go down and suck water out of the concrete. So, your choices are to either put in weep holes, or cap the ends before they go in. The downside to capping is that the cap could leak. The downside to the weep hole is that it breaks the galvanizing and exposes some steel to rusting. Between them, the weep hole seems to me to be the safer way to go, especially if the pipe is carefully painted.-- J.S.

2. 
   Cloud_Hidden | Jun 01, 2001 05:12am | #7

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   Has anyone heard of drilling small weep holes into the base and ends of pipe railing to give moisture a way to bleed out so it doesn't freeze, expand, and break the railing? How would the moisture get in there? According to the person who recommended I drill the holes, it'd get in there by normal atmospheric humidity, then it'd condense and pool at the low points in the railing.

   I've never seen holes in pipe railing before, but the advice comes from someone I'm normally inclined to listen to. Any experience with this? Thanks.

   Jim