Toilet and Tub gurgling noise!

[jtfoxman]

I am new to this site and have a question for anyone out there.
Whenever I flush the toilet I will start hearing a gurgling noise coming from the tub drain. Nothing comes up through the drain but it gurgles. This only happens when it is extremely cold for an extended period of time. After I take a hot shower the noise won't happen but it will start back up again a day later. I was thinking it was a freezing trap or vent. Any help would be great.
Thanks
Jason

Jtfoxman

[LazyPup]

It definitely sounds like you are getting a partial frost closure on the vent.

Quite often this will occur in homes that have more than on bathroom, where the problem bathroom is a distance from the main vent and has an auxillary vent.

Main vents are required to run undiminished in size from the main drain up and out through the roof. Auxillary vents may be reduced to 1/2 the diameter of the drain they serve once it is 6" above the flood level rim of the highest fixture served, but must not be reduced below 1 1/2"(min 2" if serving a water closet(toilet).

In geographic climates subject to freezing the auxillary vent is required to be enlarged to 3" at least one foot inside the structure and run 3" up through the roof to prevent frost closure.

In some newer homes that have heavy insulation and well ventilated attic spaces the incrase to 3" should be made as soon as the auxillary vent enters that attic space.

[jtfoxman]

Thanks for the info. I have 2 vents in the house. 1 vent is a 3" vent that has a cap on it that connects to our downstairs bathroom, kitchen and laundry room. The other vent looks to be only about 2" that connects to the bathroom that is having the problem. The problem only occurs with the toilet and tub not the sink. Would a cap on the vent prevent this from happening or is there another solution for this.

Thanks

Jtfoxman

[LazyPup]

Frost closure occurs on a vent from steam rising from hot water waste such as showers or laundry rising in the vent and condensating moisture which freezes on the inner wall of the pipe. Often attaching a cap aggravates the situation as it tends to catch more condensate.

You stated the problem you are having is with an auxillary vent which is 2". I would try to live with it until warmer weather then you could effect an inexpensive permanent solution by cutting the vent off in the attic space, enlarge it to 3" and run the 3" up through the roof. (That is also the proper code approved solution to prevent frost closure)

The problem is only evident with the tub or toilet due to the amount of water being discharged and the rate of discharge. Typically a bathroom sink only discharges about 1 gal at a very slow rate by comparison to a toilet which discharges it all at once or a shower which may be discharging 10 to 20 gallons. even with an obstructed vent there is usually enough air in the vent riser to effect proper venting of a sink.

[jtfoxman]

Thanks for the information. I will try the 3" pipe in the spring time. I hope this isn't harmful to the plumbing system with it backing up like this.

Jtfoxman

[LazyPup]

Given that this is an auxillary vent, aside from a bit of gurgling noise and perhaps a slight sluggishness it should not present any problems of a permanent nature.

[jtfoxman]

Thanks LazyPup. I appreciate all the advice. It seems like I can stop worrying now.

Jtfoxman

[LazyPup]

If it is not tooo difficult to access, and if it should happen to start causeing backups,,you could spray the outside of the vent pipe with water from a garden hose and that would thaw the ice out.