Fixing dryer vent by drilling hole in a beam

Hey folks - talk me out of doing something potentially unwise. I’m redoing a 2nd floor dryer vent that broke internally. I found evidence of many code issues so need to reroute the pipe. It appeared that I could fix things with a straight dryer vent run in one ceiling joist to the outdoors using solid 4†piping.

I now discovered a triple 2x10 beam in the way running above a bay window breakfast nook. (Not a true bay window, the floor extends out. It’s about 2’ wider than the rest of the room.) Also, the 2nd floor extends over this nook; there is a deep 6’ tub above it. I think the beam exists only because of the breakfast nook/bay window and the tub.

The joist span on the nook side of the beam is less than 2’ so the tub gets a lot of support. The beam itself spans about 10’. I would be cutting the 4†holes in the middle third. That makes me nervous but the old dryer pipe run won’t do either.

I was going to glue and screw an extra 2x10 plate to each side of the beam where I drill the holes, although the plates will have 4†holes too, so not clear that they will improve much.

Crazy to cut holes in the beam? Probably. Any thoughts welcome. I have no good ideas for rerouting the pipe otherwise. See photos here http://picasaweb.google.com/dereksbrown/RedoingDryerVent?feat=directlink
Thanks!

Yes, VERY crazy toi cut a hole in a triple beam like that
It was installed for a reason
A 2x10 = 9.24' - 4" you are almost cutting the beam in 1/2
Despite the fact the floor sticks out this is still a support beam
A 10' span is a pretty big span

Thanks, I agree, I just don't like the reality. Seems like it would strength the beam a tiny bit by adding the plates on either side ... but not enough.

The problem now is that I do not have a good, up-to-code mod for the dryer vent pipe. I can leave it running though the soffit but look at this bogus job from the 1988 builder. And this is only part of it, there are a few more bends and pipes to work around (see link)
http://picasaweb.google.com/dereksbrown/RedoingDryerVent

Possibly a heavy duty metal angle iron on each side could provide enough support. But now you are leaving any sizing that most people can provide. It would probably require an engineer to calc options
No chance of going out another wall?
But I suppose you thought of that before considering the beam

No, no other walls. Running up into the attic and out the roof is an option, but I have other things in the way up there that I have not fully evaluated. Attic would be complicated if not impossible. Roof is too high and steep for me to DIY and a roof laundry vent would be hard to clean.

First I think I'll try to recover the old route, installing solid 4" pipe through the soffit (these pics) around all of the DWV etc. If I can do that, there IS a mod through the garage that would shorten the run by 5' (down to 15-20') and eliminate on 90-degree bend. But that's IF I can work through the soffit. I give it a 50-50 chance.

Will post back here after the weekend with an update. Thanks, Derek

beam

A triple beam IS supporting the joists for the upper floor, not the rim joist outside the alcove. DO NOT cut it unless you get a professional's recommendation as to reinforcing it.

I am installing new basement windows and while I am at it I will be installing a dryer vent window to correct my existing code violation: a 3 inch vent.

Ian, dryer vent window is pretty cool. Haven't seen one of those before.

Rest of y'all - had a plumber come out to explore moving the copper supply pipes with me in the soffitt. Not really enough room and would still leave some other problems. Then he asked the obvious: why not widen the soffitt by 6" by putting a bay for the dryer pipe running right next to it? It basically solves all of the problems. Now I just have to do it.... Will post back with results and pics as soon as I can get it done, maybe 2 weeks. Cheers, Derek