Column vents

[Zephyr71]

Hello all. Haven't been on in a while but I'm back in the trade now so I'll be a frequent visitor since your opinions are the only ones I trust. Anyway, I just finished up replacing columns for a pergola. Old wood ones were rotted from lack of ventilation. I used 10" round tapered permacast for replacements. I just need to vent them. I've done plenty of column work for porches - which are a no brainer to vent - but never for pergola applications. Couple of guys I spoke with said they usually drill and insert a 90° 1/2" PVC fitting on the top at the inside corner. To me, it looks like a periscope. Originally I was going to drill 1" holes at the top and bottom in discrete areas and use vent plugs. Aestheticlly Looks better in my opinion. Any other ideas? Thanks

[Slaughter Construction Co]

My first thought is, what does the manufacture recommend?

If the columns are such that water will get in from above, it's sound like you need weep/drain holes more than vent holes. In that case they will need to be at the very bottom of the column. Can you prevent water from getting in?
The permacast columns are not going to be effected by moisture as wood columns. Again, check with the manufacture.
I recently installed 16 non wood columns for a similar project and they came with pages of do's and don'ts instructions.