Dryer venting issues

[MONK]

About as off topic as it can get, eh?

I own a 2 story (separated) house. I rent out the lower apartment and live in the upper. Both have washer/dryer hook ups and both are used. The contractor who renovated the house when I moved in ran both dryer vents to a single Y connector and vented them outside. There is no outside access to the vent as it's under a porch. About 6 months ago, my tenant hooked up her dryer and I noticed, every time she'd turn it on, it would partially vent through MY dryer. This is obviously unacceptable. I had a handyman in today to run an outside vent to the rear of the house.

Here's where it gets tricky. The lower 1/2 of the house is poured concrete finished in stone. The upper half is typical construction (all wood). I was planning on running the outside vent downstairs as it has a dropped ceiling thus easy access. Turns out nobody has anything that will drill a 4" hole through solid concrete and the only way to get to the little bit of wood above it (without going through my floor) is to cut a 4" hole through a floor joist. There's a pocket behind the joist that would allow the outside vent but I don't want anybody cutting 4" out of a 6" joist. Just doesn't seem like a good idea. My dryer is on an INSIDE wall so I can't vent it as most would.

I wish I had taken pics but hopefully you get the idea. Does anybody have any suggestions? I can probably hire a carpenter to go through the joist and shore it up however it needs to be done but I can see some serious $$$ going that route. I can have another vent run through the front of the house but I don't even know how the original contractor did that as it's probably 4' from the wall to whatever he drilled through. In hindsight, that probably isn't even the best idea as I don't see any way to secure/seal the pipe.

I'm hoping one of you knowledgable folks has some suggestions.

HAGO!

 

[spyder01]

I clean vents along with my powerwash business.If it was me I would call the guys at betterventing.com and ask them,if they dont know then search or post the question on their venting forum,good luck.

 

[MONK]

It appears their forum registration is closed.

 

[spyder01]

It appears their forum registration is closed.

Try calling tomorrow

 

[ulflyer]

Could you have a metal plate made with a 4+ inch hole to screw onto the joist? That should be sufficient to shore up the joist. Or perhaps a 1" metal bar along the top and bottom?

 

[Peter Aawen]

Any chance you could just lose the 'Y' connector & just run a new parallel vent pipe alongside the original from there on out?? :dontknow:

Or maybe you could put a 'wind & storm protector' type 'flap/non-return' valve in the outlet pipe on the back of each dryer (altho it might possibly still work if you put those valves anywhere in the outlet pipes running from the back of each dryer out as far as the 'Y'??) so that whenever the 'other' dryer is on & venting, the force of its output air closes off the 'other' dryer's flap valve, stopping any venting out thru that dryer. That should solve the 'wrong way' venting problem when only one dryer is on, still allow each dryer to operate as normal, and yet force any vented air to go out the right way whenever either or both dryers are operating.... :dontknow:

Dunno if any if that helps, but maybe... :dontknow: Good luck! :cheers:

 

[wyliec]

How about power exhaust after the Y, energized by either dryer.

https://www.fantech.net/our-solutions/laundry/inline-dryer-exhaust/

 

[BLUEKNIGHT911]

A 4 inch hole can be a problem or not it depends on whether it has to bear a LOAD. If it is a joist with NO SUPPORT where you need to hole then you can't make a hole - period. Forget any type of support plates, it will be un-safe. ... However if this 2x6 is the vertical support over a SILL plate and the joists run from there out ( as floor supports ) then it not really load bearing and can be done ..... Good luck .... Mike hyea:

 

[wyliec]

How about power exhaust after the Y, energized by either dryer.

https://www.fantech.net/our-solutions/laundry/inline-dryer-exhaust/

Wiring may be able to be run thru the vent if running outside the vent poses a problem; high temp insulation wiring.

 

[Bluetrees]

Monk, Home Depot (and many others) sells an in-line 4" valve to prevent outside air coming in.

How about placing it in-line just beyond your dryer but before the Y.
When the other units dryer turns on the valve should prevent that air from coming your way.

 

[oh400ex]

Peter hit the nail on the head earlier IMO.

The product you are looking for is called a "backdraft damper" (4in)
Install anywhere after one of the units but before the Y

Simple and nothing to go wrong aside from needing a bit of extra lint cleaning.
Edit: Behind the dryer for easy cleaning (Bluetrees basically said the same thing I am seeing now)

 

[bmccaffrey]

Peter hit the nail on the head earlier IMO.

The product you are looking for is called a "backdraft damper" (4in)
Install anywhere after one of the units but before the Y

Simple and nothing to go wrong aside from needing a bit of extra lint cleaning.
Edit: Behind the dryer for easy cleaning
View attachment 186057

This will work. Will let air out but not back in

 

[Lew L]

The backdraft damper will work. They are always in vent fans for bathrooms/ laundry rooms. Also ar 4" core drill will make it through solid concrete. I had to drill holes through the foundation stem wall when I added on the the house.

Lew L

 

[Gwolf]

There are ways to cut a 4 inch hole through solid concrete. None of the local contractors may not be able to do it, but it can be done. Seen it plenty of times putting pipes through 8 to 12 inch thick floors in chemical plants and manufacturing plants.

 

[Woodaddict]

yes they do make 4" core concrete drills. any type of backdraft damper, your only asking for trouble with lint build up. should SEPARATE them. i don't think building codes would even allow this double venting.
find the right plumber will have core drill. i will look over for you monday, i do alot of handyman work and just built my house with contractor, doing alot of the work

 

[trikermutha]

As Lew stated a 4 inch core bit will work for drilling a 4 inch hole in concrete.

Maybe able to rent one from Home Depot or someone local.

 

[Lew L]

And just to complicate matters:


Every 90*bend in duct work is the same as 15 to 20 FEET of straight duct. The HVAC company the did my first dryer vent did not know this as they put 6 -90* elbows to cover a distance of 2.5 ' to an outside wall ( in the wall ,down,up and out). And yes it clogged up with lint. I rectified the situation with a short length of smooth duct and 1 elbow. Dryer works great.
Good luck,
Lew L

 

[BajaRon]

Could you have a metal plate made with a 4+ inch hole to screw onto the joist? That should be sufficient to shore up the joist. Or perhaps a 1" metal bar along the top and bottom?

I agree. But there is an easier way. Get 3/8" plywood and make 2 pieces 3' long. Laminate them to both sides of the joist with construction adhesive and suck them up with some long wood screws. Unless there is a grand piano or some other very heavy object sitting right over this joist, This should give you more than enough reinforcement. I've done this myself. Much less work and cost than boring a 4" hole through solid concrete. I'd suspect there may be some rebar in there as well.

 

[Gwolf]

I agree. But there is an easier way. Get 3/8" plywood and make 2 pieces 3' long. Laminate them to both sides of the joist with construction adhesive and suck them up with some long wood screws. Unless there is a grand piano or some other very heavy object sitting right over this joist, This should give you more than enough reinforcement. I've done this myself. Much less work and cost than boring a 4" hole through solid concrete. I'd suspect there may be some rebar in there as well.

The hole will go right through any rebar that might be in the concrete. You can see where the rebar was in the cylindrical plugs that come out of the holes. The better core tools have diamond cutting surfaces.

 

[spyder01]

I agree. But there is an easier way. Get 3/8" plywood and make 2 pieces 3' long. Laminate them to both sides of the joist with construction adhesive and suck them up with some long wood screws. Unless there is a grand piano or some other very heavy object sitting right over this joist, This should give you more than enough reinforcement. I've done this myself. Much less work and cost than boring a 4" hole through solid concrete. I'd suspect there may be some rebar in there as well.

thats called sistering in a joist.I had to do it when I sold my last house and there was termite damage,but you dont do it with 3/8 plywood,use the same size wood thats already there like 2x12 and make it as long as you can easily fit like maybe 3 or 4 feet.Oh and use bolts with washers and nut if you can.If you ever have a home inspector look at it you'll be good.