Take the 2-minute tour ×
Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

I recently had the plumbing get backed up and snaked out. Things are working much better now, however, there are certain conditions (notably the use of toilet paper in conjunction with a shower or the washing machine) which result in extremely slow draining for the whole house. This also results in the showers backing up (slightly) and the sinks gurgling.

I'm thinking that the main line may need to be snaked another 20-50 feet but I want to rule out anything within the house. The main is the only common drain between the various rooms impacted so the only other thing I can think of would be the vents.

How can I tell if this is a problem in the main line or in the venting?

Edit: city sewer. At the end of a dead end road if it matters.

share|improve this question
1  
Sewer system or septic tank? –  Steven Aug 5 '12 at 4:11

1 Answer 1

up vote 5 down vote accepted

I'm afraid it's probably both. You have a venting problem because the sinks gurgle. Watch the water level in a toilet when the washer starts to drain, it'll probably drop a little. The reason you don't have a bigger problem with water getting sucked out of traps is because the main line is obstructed, minimizing the demand for makeup air through the venting system. If the mainline were not obstructed, the backed up water would quickly drain away once the traps were voided of water, providing an alternate path for makeup air.

The fact that toilet paper is a contributing factor also indicates main line problems. The waste water backing up could have caused solids to float up into vent lines and get lodged there. Hopefully snaking through the roof vents will free any vent obstructions. Depending on the nature of the blockage, simple snaking may only temporarily allow drainage. More aggressive clearing may be called for.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.