Warm air can cause condensation in attic

Q. I live in the Chicago area, where it gets cold now and then in the winter, although we’ve had little snow this season. (It’s 12 degrees now.)

Anyway, I just noticed that the house attic roof (1-by-6 planks, not plywood) is covered with frost near where it meets the outside walls (facing north). Also, most of the attic roof on the north side of the main beam is wet, and in some cases dripping on the insulation and seeping through the ceiling in one room.

I’ve lived here since 1969 and never noticed this before. What could cause this? I appreciate your insight.

A. Did you check the condition of the attic frequently before now, or did you just do so recently? My guess is that this has been going on for a while and is caused by convection of living space moisture into the attic — the most common source of attics’ excessive moisture.

Convection can take place through cracks in different materials, unglued drywall tape joints, electric boxes, holes drilled for wires and plumbing pipes, ceiling light fixtures, bathroom and kitchen fans, attic access panels and stairways.

You can try to find the paths by looking carefully, but the most reliable way to find them is to have a blow door test performed, pressurizing the house while using a smoke candle to detect the leaks.

Leaving things as they are is not healthy. Serious damage can eventually occur because the condensation is dripping onto insulation and wetting the ceiling.

If this problem has just started this winter, something very different has taken place to allow moisture convection. I suggest you examine this critically.

Q. I have a two-story house with a basement that is half above ground. This makes the roof very high. Because of many trees around the house, I get a lot of leaves and other tree stuff in the gutters, and the downspouts get clogged. This is a yearly problem, sometimes even twice a year.

Worsening arthritis makes it difficult for me to climb my ladder this high to clean the gutters and clear the spouts. What gutter guards or covers would you recommend?

A. I am not fond of any gutter guards or covers, because I have not found a type that is problem-free. My question about what happens during a gusher has not been answered satisfactorily by firms that install covers. Only one representative was honest enough to tell me that water would shoot over the gutter.

I have tried DCI’s Flo-Free Leaf Guards on our gutters, but I found they collect tree debris at the slight hump of the guard where the roof terminates. The company sent me a special hooked attachment that is fitted onto a length of 2-by-4-inch downspout to allow cleaning from the ground, but that would not work with your high roof.

Some readers have reported good luck with other brands of gutter covers, but I haven’t tried them.

Consider these options:

Ÿ Take your chances and choose one of the gutter guards on the market.

Ÿ Have a gutter installer replace your downspouts with commercial ones. They are 3 inches by 4 inches (twice the cross section of regular downspouts) and are almost sure not to clog.

Ÿ Change to commercial downspouts and gutters (6 inches wide instead of 5 inches, and able to hold more debris), although that may not entirely solve your problem.

Ÿ Replace your gutters and spouts with the Rainhandler system (rainhandler.com) if your town does not mandate standard gutters. Rainhandler consists of 3-foot strips of small horizontal louvers screwed to the fascia boards. Not only do the strips not collect leaves or other tree debris, but they also spray roof water in a showerlike pattern, preventing the usual ditch that roof water creates on the ground.

My original concern about Rainhandler was whether it could withstand the weight of icicles. This fear was allayed when a friend sent me photos of his Rainhandler sporting huge icicles, several feet long, with no damage to the system. I have since successfully installed the Rainhandler on the high side of our house — no more gutter cleaning!

Q. You’ve mentioned Sikaflex many times for caulking around tubs. I went to Home Depot and could not find the right type. I’ve also searched the website and can’t determine what product I need — Sikaflex 1C, 1A, Crack Flex? Please help.

A. Last time I checked, Home Depot carried Sikaflex polyurethane caulking under the name Sika Construction Sealant; it looked pretty much the same to me. It was in the masonry supply aisle and not with all the other caulking materials. When I first asked, the clerks in the caulking department didn’t know what I was talking about. I found it by searching around.

I have used Sikaflex-1a around tubs for decades. Be aware that it must remain dry for seven days to allow time to cure or it is likely to turn pink. If it is not possible to keep the caulk dry for that long, you should either tape plastic thoroughly over it for a week to shield it or use another brand of tub caulk, such as DAP Kwik Seal 3.0 caulk with Microban. It’s silicone-based, and it peeled off in about a year when I tried it around half of our tub while using Sikaflex-1a on the other half.

Q. I worked with a person who owned a large and rather expensive house near me in central Massachusetts. The plumbing vent through the roof was copper, and it would frost up and freeze completely in the winter. Your comments?

A. A metal stack vent is more likely to freeze than a PVC one. Was the vent 4 inches in diameter? That size is unlikely to freeze completely in your climate.

If there is access to the attic, the entire visible section of the stack vent can be wrapped with loosely tied fiberglass. If the stack is less than 3 inches, consider replacing it from the attic floor through the roof.

Q. We had a Dacor cooktop installed when we remodeled our kitchen. Shortly thereafter, black stains appeared on one burner after simply boiling water in a saucepan. We have tried all kinds of cooktop cleaners and remedies, but nothing has helped. Any suggestions?

A. According to Dacor technical services, if your cooktop is stainless steel, first try Bar Keepers Friend, available at Home Depot, Target, etc. If that does not remove the stains, try Flitz (flitz.com). If your cooktop is not stainless steel, Simple Green or 409 should work.

If you do not succeed, contact Dacor at (800) 793-0093 and follow the interminable prompts — the bane of today’s business world, geared to the business’s convenience and not the consumer’s — until you hear the right digit to punch.

Q. We are planning to paint our house shutters (plastic) this summer. How should they be prepped, and what kind of paint do you suggest?

Our front door has a pane of glass, and even after 10 years, the caulking melts and runs so the door really never looks decent. I would appreciate your thoughts on that, too.

A. After thoroughly cleaning your plastic shutters, prime them with B-I-N, followed by a top-quality outdoor latex paint.

The caulking of the glass/metal joint runs because it is probably overheating. This can occur if the door and the glass trim are painted a dark color or if there is a storm door and the sun shines on the doorway several hours a day.

If the storm door is the problem, take off the storm panel and leave the screen year-round.

Interesting follow-up: “I make sure I read your column every week. I am writing in reference to your … column about the source of a sewer smell coming from the shower drain. We had a similar problem. Ours, too, was intermittent but occurred only during blustery days (not a temperature condition). When we plugged the shower drain with a stopper, the smell went away, so we kept focusing on the shower drain and its vent, yet we could find no issue with either. (This included excavating through tile and a cement floor to expose the drainpipe!)

“Another plumber investigated the toilet and found its seal to the drainpipe was in poor condition. When he replaced the seal, the sewer smell coming from the shower disappeared and has not returned in the two-plus years since.

“My advice is to check that toilet drain seal. Although the toilet would seem to be disconnected from sewer gas coming from the shower drain, it was the solution for us, and it’s relatively inexpensive to do this.”

Thank you for sharing your experience. It backs up what I mentioned as a probability to the reader with the same experience, although it may seem illogical to think of the toilet seal when everything points to the shower drain. Toilet seals are generally the source of sewer smell in bathrooms. Your experience validates this and demonstrates how the unexpected can often be the culprit.

Ÿ Henri de Marne was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. Write to him in care of the Daily Herald, P.O. Box 280, Arlington Heights, IL 60006, or via email at henridemarne@gmavt.net.

© 2012, United Feature Syndicate Inc.