Drip edge on WF beams
Drip edge on WF beams
(OP)
Architect is using W16x40 to put a horizontal band around the roof edge of a 1 story building. The length will be about 150 feet!
Initially he showed a 1/4 x 1/4" groove machined on the underside of the bottom flange. I didn't think that was very economical and suggested a piece of bar stock welded to underside - he didn't like that for appearance reasons. I called around and couldn't find any fabricators capable of milling such a groove.
He also didn't like idea of just butting some sheet metal flashing to the underside and using some good sealant.
Now, he has called for a weld bead to form the drip. I can't see that looking too good either!
Anyone done something similar?
Initially he showed a 1/4 x 1/4" groove machined on the underside of the bottom flange. I didn't think that was very economical and suggested a piece of bar stock welded to underside - he didn't like that for appearance reasons. I called around and couldn't find any fabricators capable of milling such a groove.
He also didn't like idea of just butting some sheet metal flashing to the underside and using some good sealant.
Now, he has called for a weld bead to form the drip. I can't see that looking too good either!
Anyone done something similar?






RE: Drip edge on WF beams
You say machining a drip isn't economical. A W16x40 fascia is?
RE: Drip edge on WF beams
RE: Drip edge on WF beams
We originally had HSS 16x6 around the top, but changed to W16. Need width of flange to project out from face of wall and attach handrail!
He resisted the welded on bar drip!
Fab shops had plasma cutters & other fancy equipment, but said they couldn't cut groove. Maybe a diamond blade in a Skill saw?
RE: Drip edge on WF beams
RE: Drip edge on WF beams
Or epoxy a 9 gage steel wire to the bottom.
Or a series of overlapping yellow sticky notes.
Or tell the architect..*&%^%%^^$##%^*(&*^%^
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RE: Drip edge on WF beams
RE: Drip edge on WF beams
RE: Drip edge on WF beams
Cost of milling a notch in the flange? Ship it to milling machine, run and load WF through milling machine, pick up back off table and ship back, etc, etc, etc. Lots!
Cost of welding the edge? Lots per foot of weld.
RE: Drip edge on WF beams
Dave
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RE: Drip edge on WF beams
RE: Drip edge on WF beams
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: Drip edge on WF beams
Dave
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RE: Drip edge on WF beams
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RE: Drip edge on WF beams
Seems to me there are several options, once you understand how absolutely essential this detail is to the Architect’s ego and his winning of that world design award. And, you are standing in the way of his future fame and fortune. Have the Arch. go to the rolling mill with his purty pitcher of the shape he wants. For a nominal fee they can have some rolls made just for his beautifuler section and he can use that on every building from now on, he can even patent the shape. Think of all the machining costs he will save. Have him order the W16's early and have them delivered to his home or office. Then he can get out there during his extra time, with his trusty vice grips and just bend the tip of the flange down a few degrees to make the drip lip. He could buy a DREMEL tool and grind drip lips or grooves anyplace his little heart ane mind desires. Remind him that he should do this on the outside flange tip so it will drain outward. Some of them aren’t too sure of this concept of keeping the water out of their bldgs., given how many of their bldgs. leak.
Why are you worried about this? That’s an Arch. detail and on the arch. budget. Soon enough he will be asking you to eliminate every other beam and column, to help pay for this special detail, since your structure is causing the bldg. budget to explode.
RE: Drip edge on WF beams
RE: Drip edge on WF beams
RE: Drip edge on WF beams
Check out Eng-Tips Forum's Policies here:
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RE: Drip edge on WF beams
RE: Drip edge on WF beams
Check out Eng-Tips Forum's Policies here:
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RE: Drip edge on WF beams
If the bottom flange is completely free and does not come in contact with the exterior wall, don't do anything. Just let the water drip off the flange. It seems to me that any rain accumulating on the beam flange will be due to wind driven rain.
A few other ideas to combat the water.....choose and equivalent shape with tapered flanges, drill drainage holes in the bottom flange (and account for the holes in the beam design)
RE: Drip edge on WF beams
Inside edge is barely bearing on roof deck edge. We need plate brackets to attach it to the deck.
For tapered flange member, there is no 16" S shape - goes from 15" to 18".
The whole driver for this crazy detail is the Energy Code, requiring insulation on CMU walls and bunches in the roof! I've had a number of these driving structural to go through contortions to accommodate the Code and still have something that is not structurally unstable. Anyone else having else experiencing headaches like this?
RE: Drip edge on WF beams
the energy code is very heavy-handed if it's not checked by comprehensive design process. the energy code would have you holding everything together with tape if you let it. z-girts and steel anchors still work great. too often prescriptive values are used w/o attempt to model for performance.