Homeowners dealing with a bubbling, splashing toilet

Q. I really your enjoy your weekly column on home repair; it is very interesting and even more informative. I've had an ongoing issue with my toilet and I was hoping you might be able to help.

When one of my residential toilets is flushed, air bubbles appear in the water within the toilet bowl. In addition, there is some upward splashing from the air bubbles and it's unsanitary.

An upstairs toilet, directly above the other, does not have the same problem, and the problem didn't exist with a prior toilet in the same location. I have lowered the water level within the toilet tank and it only minimized the issue but has not solved the problem.

I have contacted American Standard and they have no reported issues with this model of toilet. One customer service representative felt there might be an improper seal with the wax ring. I asked a plumber about the issue, and he said he was not aware of any air bubble/splashing toilet problem.

Are you aware of such a problem? How may I resolve this issue? Is the toilet defective or is it a sign of a larger problem?

A. This is a tough one. Is the toilet plugging up a lot or does it remove all waste every time? Is the water in the bowl at the proper height? Does this occur on every flush?

If the water in the bowl is very low, it will glug and splash, looking like bubbles. Low water in the bowl can be caused by the fill valve hose not correctly positioned into the overflow tube.

The flush time may be too short or you may have siphoning occurring, which causes low water in the bowl. If siphoning is the problem, there may be a venting problem, but you should have noticed it with the earlier toilet.

You may need to have a plumber check out your drainage lines. To find out if the toilet is defective, you would need to replace it with a new one and see if this solves the problem.

Q. For years I've followed your column with interest, but have never seen our problem addressed. I hope you can offer some advice.

We finally had a water softener installed a few years ago and have it serviced at least once a year by a professional water softener company.

Since the beginning, after the system rejuvenates, we have air in the lines. This has caused problems when bathroom stools are flushed. I asked the professional who services the water softener what could be done about it and he said there's nothing to do. My daughter and son also have softeners in their homes, but they do not have problems with air in the lines after rejuvenation, so there must be a way to solve this problem.

Can you help?

A. Your water softener specialist should check the backwash valve; it may not be closing all the way and could be introducing air into the lines.

A new control head may correct this.

Q. I have been reading your column for years. Thanks for all your advice. I do remember you talking about roof shingles before, but of course I didn't save the clippings.

I am going to have a new fiberglass shingle roof installed in the Chicago area. I got some estimates for the job - most about $8,000.

My question for you is: Which brand of shingle will be best? Two different brands have been recommended. I have a two-story colonial and will be installing three rows of ice and water shield on the south side. I have ice dams at times, created on very sunny days. I do rake the roof with a plastic snow rake. I hope to never do that in the future.

A. This is a difficult question to answer because most shingle manufacturers have had quality problems, some having suffered class-action lawsuits.

If you Google "class action suit against roof shingles," you can see the extent of the problem.

Contractors I know are using CertainTeed and BP, and have no reported failures in the last few years, but it is too short a time span to be certain that the inherent manufacturing problems have been solved.

The recommended practice is to apply an ice and water protective membrane at the eaves, in valleys, around chimneys, skylights and any other roof penetrations. At the eaves, coverage should extend a minimum of two feet above the intersecting line of the wall below.

Raking a roof is not the best practice. Not only can it damage the shingles, but under severe weather, it can create ice dams at the base of the snow pack.

Q. Like many others, I read your valuable columns and hope you can give me some guidance.

My house was built in 1977 in the northwest suburbs of Chicago and has gable vents. It was resided five years ago. A new roof was installed three years ago, and I was persuaded to have ridge vents added, even though I think you advise against having both.

Last January, I noticed a small wet spot on my master bedroom ceiling the size of a silver dollar.

The ceiling is foil-backed board. Insulation is blown with batt (no paper backing) overlays, about six inches deep. The two upstairs bathrooms are vented to the outside and insulated.

I went up into the attic and found frosted roof nails over the wet location. Also, the insulation was wet for about 18 inches around that point.

My guess is there is warm air that condenses on the nails and melts periodically. I don't know of any obvious source. I'm not sure if the soffit vents are all open, and I'm not sure what effect the gable and roof ridge vents have.

Any guidance is appreciated. Thank you very much in advance.

A. Your guess is correct: Warm, moist air is convecting from the conditioned spaces into the attic. It is essential that you find out where this convection occurs and deal with it.

The best way to do this is with an energy audit that includes a blow-door test and perhaps an infrared scan.

The photos you sent are very helpful in my being able to determine the problem you have.

The reason why ridge vents and gable vents are not compatible is that air, like water, seeks the easiest path. Ridge vents are exhausts, and gable vents are the closest intake to satisfy the lack of equilibrium caused by the negative pressure induced by the ridge vents.

You can see on the photo of the ridge vent that the plywood is almost completely clean on both sides of the ridge vent. But, as you look down the roof sheathing, the damage caused by long-term lack of adequate ventilation and excessive moist air convection is increasingly severe, and is worse at the eaves. There is heavy frost on the roofing nails, and I can even see some signs of minor delamination on one section of plywood.

It is possible that the soffit vents have been blocked by insulation, rendering them useless and aggravating the dearth of ventilation. I can't see any light showing at the eaves where the sheathing is affected the worst.

Another concern I have is that it looks like the bathroom vents seem to join before exiting through the roof, but I can't see how they do so. This is a very poor practice, as under certain circumstances, the discharge from one bathroom can be sent into the other one instead of being vented outside.

I have seen examples of this where a smaller bathroom was covered with mold even though it was seldom used, while the main bathroom was used daily by most of the family. It is also a very poor practice to vent bathroom fans through a roof in cold climates. Condensation can run down and eventually rust the fan, damage the ceiling, wet the insulation or leak through a small hole. It is possible that this is what has wet the insulation and is causing the small silver-dollar-sized leak on your bedroom ceiling.

Bathroom vents should be laid flat with a slight slope to the outside and should terminate through gable walls. It is also best for the vents to be made of bell-end solid plastic pipe, which will not deteriorate over time, as flexible ones usually do.

If you decide to have an energy audit, followed by the sealing of all convective paths, the contractor performing the work should make sure that the soffit vents are clear of insulation and open. The contractor should also seal the gable vents with exterior grade plywood (preferably pressure-treated) painted a matte black on the exterior side.

You should tend to this as soon as possible before further damage is done. Structural deterioration is not far behind, and you are fortunate that your roof is sheathed with plywood and not particle board, which probably would have failed before now from the extent of the damage I see, as it is not as resistant to moisture.

Q. How can I remove fireplace soot from the tile, screen and glass doors in my gas fireplace? I forgot to open the flue vent once last winter and the entire interior is covered with a layer of black soot.

A. Make a solution of mostly ammonia, a small amount of white vinegar and a little water. Using a spray bottle is best. Or apply the solution with a clean cloth or paper towels. Let it stand for a few minutes to penetrate the soot. Use paper towels to clean the affected surfaces.

You may have to apply the solution more than once depending on how thick the soot deposits are. You may also need to use a non-scratching scouring pad if the deposits are stubborn.

• Henri de Marne was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. His book, "About the House," is available at www.upperaccess.com. His website is www.henridemarne.com. Email questions to henridemarne@gmavt.net, or mail First Aid for the Ailing House, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.

© 2016, United Feature Syndicate Inc.