Blind bolt (Hollo-bolt, Box bolt) connection question

[cliff234]

We are framing a roof screen with HSS sections and are connecting the members with blind bolts (also known as Box Bolts or Hollo-bolts). Is there a need to be concerned about water seeping into the HSS's through the bolt holes? If the bolts are properly tightened and connection plates are sufficiently thin, I would think the connection would be tight and water infiltration would not be a concern - but I am wondering if anyone has ever had a similar concern or if they have heard of any problems due to water infiltration into HSS's through such connections. Thanks!

 

[JohnnnyBoy]

I've heard in other situations drilling a small hole at the bottom of the HSS to allow moisture to seep out if there is infiltration. Although I will let the other experts comment on whether there will be infiltration.

 

[canwesteng]

Will it be air tight to stop moisture from getting in? I doubt it. And you can never inspect the inside of the HSS.

 

[MotorCity]

If it were me, I would either use some sort of cushioning washer or sealant around the bolts. I would also provide weep holes at the bottom as a belt-and-suspenders approach.