Hello all.
I’ve got a stinky problem I’m hoping to get some help with.
We had an addition put on our house last summer/fall – construction was completed around mid-October. We added one room each on the first and second floors on the back side of the house. We live on a fairly steep hillside with one house 400′ up the hill behind us and one about the same distance down in front – both set off to the right of ours.
As the warm weather has finally started to set in, we have, of course been opening up the windows during the day. We’ve found though that these two rooms get really stinky shortly after the windows are opened. It sort of smells like somebody’s septic tank (all three houses have them) but I couldn’t say for certain that’s what it is.
The odd thing is, it’s only the two new rooms. I can open up every window in the house, and only these two rooms have the smell. The other odd thing is, if I go outside, even right outside the windows of the new rooms, I don’t smell anything – its only inside…but it goes away once the windows are closed.
Any thoughts on what could possibly be causing this?
-Photog
Replies
Do either of these rooms share a plumbing wall? What is the orientation of the plumbing vent to the new windows?
[quote][b]Do either of these rooms share a plumbing wall?[/b]
Yes, both. The first floor room always did (the addition on the first floor was actually an expansion of an existing room). It shares a wall with the first floor bathroom and all of the plumbing is in that wall. Second floor bathroom is directly above ff bath, and was originally in a shed dormer (house is a cape). New second floor room shares a wall that was part of the dormer - and again, all plumbing is in that wall.
[quote][b]What is the orientation of the plumbing vent to the new windows?[/b]
Vent stack is in the roof of what was the shed dormer for the 2f bath
Could it be some sort of new air current that is driven by the new roof in relation to the vent stack? In addition to maddog's thing to check, maybe adding a coupling and extra length on to the stack could help...if it's the kind of vent that I'm thinking of where the PVC just barely sticks out of the flashing rubber.
Any possibility that you punctured the drain stack or disturbed that wall enough that you opened up a crack in the stack.
With the windows open that changes the pressurization with in the house.
That was the other thing I was thinking, of course, but thoughts of ripping into the new drywall chased that out until the other possibilities have been eliminated.
Were you around when the framing/roof was being done?
Edited 4/14/2003 1:24:20 PM ET by johnnyd
I was around when the roof framing was done, and in fact the vent stack had to be moved slightly from its original location because it would have ended up in a new valley.
But again, if there was a problem with it being cracked or somehow otherwise failing, wouldn't the smell be evident in other areas of the house (i.e. the bathrooms) and not just confined to the two new rooms? If I open all of the windows in the house except those in the new rooms - no smell.
it seems pretty clear that the pressure difference between the sewer gas SOURCE and the inside of the two rooms changes when those windows are open. If it's a leak from a crack within the building, the open windows provide an easier way than the end of the stack for the gas to flow...OR create a wierd draft situation where the gas from the end of the stack eddys down into the rooms. I suppose you could climb up there and temporarly plug the end of the stack to rule out the eddy issue. That would probably also make the smell worse if there is an interior fault. Just make sure you don't flush any toilets while it's plugged.
If it turns out to be just the wind currents around the house carrying sewer gas back into the house, can a mechanical vent be used in that situation? I thought I saw an ad in FHB for a 3 inch mechanical vent. I have a similar situation in that I would like to (in theory) eliminate some vent stacks from penetrating our roof, and wasn't sure what the code was with studer vents.
Aaron
Photog,
Get your plumber to do a smoke test. You killing that septic tank with silver nitrate?
KK
I'm with JohnnyD, but further than that, did you add plumbing--a new tub or toilet, sink etc? Could be getting gas through the drains, especially if you haven't used them much or at all. Seems like a vent issue though. If you have a toilet flange open but not temporarily plugged up that would be a likely suspect.
Nope, no new plumbing added and existing is used regularly.
If gas was coming through the drains, wouldn't the bathrooms (and other rooms) smell? They don't.
Did you have any disagreements with anyone prior to the drywall going up?
I think you've gotten some good suggestions. To expand a little on what johhnyd said:
Try sticking on a 3' piece of PVC with a coupling (don't glue it, just stick it on). Unless it's particularly windy it will prbably stay on for a long time.
I'm thinking that a draft over the roof probably isn't the problem, but this might be the least expensive thing to try.
Any jackass can kick down a barn, but it takes a carpenter to build one.
I think Johnny got you covered, have a similiar situation on a summer home and when breeze is right I can smell sewer gas.
That valley probably offers a great downdraft for the vent pipe fumes. I'm also thinking an extention might help.
Bob
"Rather be a hammer than a nail"