Smell of rat urine in attic

There used to be a lot of rats in my attic, at least from time to time over the years. I'd set out rat traps to control them and they've been eliminated, at least for the time being (none for over 6 months). Denying them entry will have to wait for some other stuff to happen here (foundation work, etc.) but the traps have made my house discouraging to them, and they aren't willing to try anymore.
My roof was completely replaced in November and I spent a few weeks completely cleaning out the attic. After the tearoff, the mess up there was huge and daunting, but I buckled down and cleaned the attic as never before, ultimately vacuuming out every rat turd I could find, as well as removing all the debris from the roof job.
Yesterday, there was an unfortunate accident. A workman was trying to clear a bath tub drain clog with a waterhose-powered device that forces water down the drain in hopes of clearing the drain. The water backed up the roof vent, which is not uncommon. Unfortunately, the vent had a hole the size of a dime in the attic and much water (several gallons, evidently) sprayed over an area of about 100 square feet, most of it dripping (or pouring) through the ceiling. Luckily, summer starts tomorrow and the weather here is warm and dry, and with a big fan in the attic, the lath and plaster ceiling/attic-floor barrier between the upstairs and the attic appears almost dry already, some 15 hours after the "accident." My problem at the moment is the smell, and it's filling the house. The water on the lath and plaster has apparently reactivated impregnated rat urine. I figured that out this morning after enduring the smell all night.
I figure the smell will subside as the ceiling truly dries, but am fearful it will not. Can I get any hints or suggestions? Maybe an alcohol-thinned coating of shellac brushed on the lath? That's all I can think of but there may be better ways to deal with it. Or will that smell go away when things really dry out? Maybe it never really was not there, but it was just subtle enough that I learned to ignore it. There's going to be a mini heat wave here and I think the ceiling will be dry by the weekend. Thanks for any ideas.
Dan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
PS. I'm really glad I bothered to install 4 large gable vents in my otherwise vent-free attic before I had the house re-roofed (14" x 24"). Those, in addition to the ridge vent they put in, has given the attic considerable ventilation, and will really help dry things out over the next hours/days. I hope it's windy.
Dan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yuckkk! Shellac is supposed to be a good barrier for odors. I'd get it reasonably dry and put a coat or two on. The plaster may be harder to do, but a coat or two of shellac based primer inside may do it. Check out Zinnser and Kilz.
Even if it dries out, a long rainy period may bring it back. I'd seal it up.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:
:
:> :> I figure the smell will subside as the ceiling truly dries, but am :> fearful it will not. Can I get any hints or suggestions? Maybe an :> alcohol-thinned coating of shellac brushed on the lath? That's all I can :> think of but there may be better ways to deal with it. Or will that :> smell go away when things really dry out?: :Yuckkk! Shellac is supposed to be a good barrier for odors. I'd get it :reasonably dry and put a coat or two on. The plaster may be harder to do, :but a coat or two of shellac based primer inside may do it. Check out :Zinnser and Kilz. : :Even if it dries out, a long rainy period may bring it back. I'd seal it :up. :
Thanks. I can easily access all (or very nearly all) of the lath and plaster that was wet yesterday in that accident, and I can do these things with that. But I don't know that I can do these things to the entire attic. I did manage to vacuum the entire attic and clean it out almost entirely by virtue of a couple of things:
1. A long custom-made rake.
2. A shop vac with attachments including two extenders and lieing on a board placed over the floor joists in the attic. With those, I could vacuum even the corners and right up to the blocking at the soffits.
Outside of some crazy kind of spraying, I don't have a chance of getting anything on the wood at those extreme edges of the attic. Yes, it stinks up there, but mostly I don't notice it except last night - it was pretty bad!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dan_Musicant wrote:

Google cat urine clean-up. you may get some tips. Smell may never go away, especially when high humidity. Shellac will help after neutralization to seal up everything. Apply liberally and maybe multiple coats. It dries fast. Bins is also a shellac based primer, regular shellac may be preferable, not sure. Not sure on best neutralizer but pet store may have something (Natures miracle? or am I getting confused). Also carpet cleaners may have a pet stain cleaner. You do not want a scent to cover the scent, you want something with enzymes to kill the smell.
Or, burn the house down.
Yick - Good luck
Inviato da X-Privat.Org - Registrazione gratuita http://www.x-privat.org/join.php
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dan_Musicant wrote:

Dan-
I would try to kill / neutralize the smell rather than covering it up. That being said my initial try would be a bleach water mix about 1 pint to a gallon. I have used this with success before but sometimes requires repeat apllications.
I did a qucik search & found a
http://www.woodweb.com/knowledge_base/Removing_Urine_Odor_from_Stored_Lumber.html
to save everyone time, suggestions of bleach & vnegar (& the typical "you'll never get it out) the last post on the page was from a guy who rehabs homes & he uses
OdorXit Concentrate.
http://www.odorxit.com/Gen.htm?gclid=CLOw1suw1YUCFRr7SAodQyiEKA
I've never heard of or used the stuff.
If possible I would try to mount a couple cheapo box fans (in the attic blowing outward) right up against the gable vents. Open the attic access & you'll get god ventilation of the attic. It will help dry the attic quicker
cheers Bob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ventilate and dry attic, sprasy everything effected with Kilz, it will seal in the odor you CANT clean it up.
This is akin to fire restoration to elminate odor.
seal both sides of plaster with kilz once its completely dry
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:
:Ventilate and dry attic, sprasy everything effected with Kilz, it will :seal in the odor you CANT clean it up. : :This is akin to fire restoration to elminate odor. : :seal both sides of plaster with kilz once its completely dry What kind of Kilz are you talking about? There's several kinds. Thanks.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
:Dan- : :I would try to kill / neutralize the smell rather than covering it up. : That being said my initial try would be a bleach water mix about 1 :pint to a gallon. I have used this with success before but sometimes :requires repeat apllications. : :I did a qucik search & found a : :http://www.woodweb.com/knowledge_base/Removing_Urine_Odor_from_Stored_Lumber.html : :to save everyone time, suggestions of bleach & vnegar (& the typical :"you'll never get it out) the last post on the page was from a guy who :rehabs homes & he uses : :OdorXit Concentrate. : :http://www.odorxit.com/Gen.htm?gclid=CLOw1suw1YUCFRr7SAodQyiEKA : : :I've never heard of or used the stuff. : :If possible I would try to mount a couple cheapo box fans (in the attic :blowing outward) right up against the gable vents. Open the attic :access & you'll get god ventilation of the attic. It will help dry the :attic quicker : :cheers :Bob Thanks, Bob. Good idea about the fans, but I caught one little piece of luck in this "disaster," and that was the weather. It's been less than 24 hours and things in the attic seem virtually dry. I'll leave the honkin' 20" box fan running until I go to bed tonight, though, just for good measure. I don't want to hear it again overnight, and I hope (and think) the smell won't be noticeable by then (in my bedroom, anyway).
I think that smell must have been in the attic all this time but pouring water in there REALLY brought it out in a BIG WAY!
I went to those links you have above and read them. Will see how things seem by this weekend, and maybe do some stuff to deodorize the attic if at all feasible if it seems to be an issue. I think it is but don't know how practical it is to try to do anything about it. The attic is really big (~20' x 40') and a lot of it is difficult to access where the headroom gets to be less than a foot (near the walls). If it's just a matter of deordorizing the portion that got wet, that IS doable.
Dan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

One thing to think about, is that bleach can react with ammonia to make a poisonous gas: http://www.google.com/search?q=ammonia+bleach+reaction
We've used odo-ban to remove bad odors. It also kills mold, mildew, viruses, etc. it's a little perfumey, but fades with time.
Be careful, and use lots of ventilation.
--
May no harm befall you,
flip
Ich habe keine Ahnung was das bedeutet, oder vielleicht doch?
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

There is a good chance it's not rat urine at all, but the hole in the vent pipe allowing the sewer gas in the attic. Repair that hole ASAP. Sewer gas can be flammable and even explosive so you do not want it going in the attic.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 21 Jun 2006 00:07:53 -0500, ---------------@--------------- wrote:
: :There is a good chance it's not rat urine at all, but the hole in the :vent pipe allowing the sewer gas in the attic. Repair that hole ASAP. :Sewer gas can be flammable and even explosive so you do not want it :going in the attic.
Hmm. Well, it will be at least a couple weeks before the pipe can be replaced, looks like. I will duct tape the holes. There's a couple of them about 2 inches apart. A bit of duct tape will stop gases from getting into the attic for the time being, at least through the holes I have seen. Thanks!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
After drying out and turning off the fan, the smell was mostly gone. It wasn't something I noticed during the night, anyway. Yes, it's likely to reactivate some in humid/rainy weather. I will look into sealing or neutralizing the wood or both.
Dan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Site Timeline

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.