Real estate

Address

How to fix wet walls, mold, and other damage caused by winter

Water that slipped under an ice dam stained this bedroom ceiling.

Water that slipped under an ice dam stained this bedroom ceiling.

Dear Merriam-Webster:

Let the spelling fit the sentiment.
“Damage” is “DAMNage.”

Signed,

The Concord Carpenter

In this home, water that slipped under an ice dam caused the plaster to bubble.

Winter blankets us in misery every year, but 2015 brought with it the perfect storm for ice dams and inflicted the severest punishment those dams can dish out.

We’ve had 108.6 inches of snow fall on our roofs. (To put this into perspective, Logan Airport budgets for about 48 inches a year, according to the Massachusetts Port Authority.) To add insult to injury, we also endured bitterly cold temperatures.

Birth of an ice dam

Advertisement

By now I’m sure you know that ice dams occur in regions with deep snow and frigid temperatures. Compounding this problem are complex roof structures that trap snow, as well as inadequate insulation, ventilation, and air-leak sealing.

As snow increases in depth on a roof, it becomes an effective insulator — think igloo! Heat escaping from the house warms the underside of the roof and melts the bottom layer of snow, which drains down the roof, slips under the insulating snow cover, and freezes once it hits a colder surface like an overhang. The melting snow above feeds the icy layer, which grows thicker and thicker, creating an ice dam.

Get The Weekender in your inbox:
The Globe's top picks for what to see and do each weekend, in Boston and beyond.
Thank you for signing up! Sign up for more newsletters here

And before long, the water builds up and creeps under the asphalt shingles, springing a leak inside the house.

Leaks and damage

Building-science experts advocate that we need to employ a whole-body approach to our homes, to look at them more as complete systems than at just the symptoms. Using this house-as-a-system approach, we can not only repair the damage, but potentially prevent it.

In this article I want to focus on repairs.

Insurance claims

Advertisement

Some folks do not realize they have policies that allow them to make a claim for water damage caused by rain, snow, or ice or accidental leaking or discharge from plumbing, heating, air conditioning, or a refrigeration system. The question to ask is does it make sense to make the claim or just foot the bill yourself? To make a claim, you need to contact your insurance provider and speak with an adjuster. Be prepared to provide:

 Photos of the damage. If you are claiming damage to contents and have that coverage, provide photo evidence of that, too. The description should include the make/model, size, material, and replacement cost.

 A written estimate, from a contractor, for the repairs needed. Estimates should include a description of the work and a breakdown of the costs by materials and labor. The replacement materials should be those of the same kind and quality of those being repaired.

 Be sure to check your homeowner’s insurance to see if it will cover mold. If you find evidence of mold, your insurer will want to be contacted immediately and most likely will assign an adjuster to inspect the site. Be careful, a mold claim might affect your ability to get insurance later.

OK, so you have a leak. First step: Stop it! Next step: Dry! I recommend running fans ASAP. (If you have mold, however, fans will just spread the spores.) This may mean calling in professionals with special fans and carpet-cleaning machines.

Wet hardwood floors

Once you’ve stopped the leak, use fans to dry out walls, ceilings, and floors. Wallboard and plaster will dry quickly, but hardwood floors may take longer.

Solid hardwood floors react to water in three ways — they cup, crown, or buckle:

 Crown: The boards raise up in the middle.

 Cup: They raise up along the edges.

 Buckle: They come apart and need to be replaced.

All is not lost when a hardwood floor gets wet; oftentimes it is not evident if the floor is damaged or just ticked off!

I once overflowed my kitchen sink and flooded the hardwood floor. After vacuuming up the water, I ran fans in the kitchen to dry the floor and in the basement to get the moisture out of the subfloor. I was lucky; there was no visible or long-term damage.

According to my flooring contractor, R.C. McKinnon Wood Flooring in Hyde Park, it can take anywhere from three weeks to five months for a hardwood floor to settle down after getting wet and crowning or cupping.

If there is no staining and the floor settles down, you’re good to go. If not, you’ll need to sand and refinish or replace the flooring.

What will this cost you? Here are some guidelines, assuming you hire an experienced, quality, and licensed contractor who uses good materials:

 Sanding and refinishing: Plan on spending $2 to $3.50 a square foot. The higher range is assuming that the area needs to be stained to match an existing floor color.

 Replacing and finishing: Figures vary by manufacturer and wood type, but here’s one example. Plan on spending up to $10 a square foot for 2¼-inch red oak flooring.

  Removing and disposing of the old floor: This all depends on the contractor, but a good rule of thumb is to budget $3 a square foot.

Wet walls

How do you dry insulation inside a wall/ceiling cavity or the backside of the wallboard?

The BEST solution with wet insulation is to replace it. Wallboard can be dried in place if there is no obvious swelling, the seams are intact, and you can get adequate airflow to the wet surfaces. If not, remove and discard the insulation. Wall cavities should then be ventilated and dried.

I’d be lying if I said I never violated this principle. Several years back, I had two simultaneous ice dam leaks in my house — prior to installing a new roof with an ice and water shield. Luckily, I was able to stop the leaks within an hour of noticing them.

I did not open up the wall because I have extensive wainscoting and crown molding. That does not mean mold did not grow in that wall cavity. I’m sure it did.

(Need to make a hole? See my article on how to fix one on the preceding page.)

Mold concerns

A lot of people ask me how long it takes mold to grow after a recent water incident. First, let me just say I’ve never worked on a house that didn’t have mold somewhere. Mold is a microorganism that’s found everywhere. It can grow on almost anything as long as there is enough moisture. Inside your home, mold grows quickly on damp surfaces like bathroom walls and trim around windows. Mold may look like furry growth, black stains, or specks of black, white, orange, green, or brown.

Many researchers say mold will start to grow in the first 24 to 48 hours after a leak, under ideal conditions. Carpets get moldy very quickly. Older carpets that have dirt as a food source start smelling moldy after being wet just a short time. It may be a week or two before it grows to the extent that it is visible to the naked eye as spots on drywall or carpet pads.

In my experience, you usually don’t get mold when you stop a leak quickly and dry out the area properly. It’s the longer term, constant leaks you have to be concerned about.

Mold spores need three things to grow and thrive:

1. Food (cotton, leather, drywall, wood, and paper products, among other things)

2. Water (good circulation throughout the home is important to eliminate dampness or potential moisture, especially in attics, basements, crawl spaces, and laundry rooms)

3. Optimal temperatures (unfortunately, that range is broad — 32 to 120 degrees Fahrenheit; although a temperature of 70 to 90 degrees is the most conducive for mold growth). Mold doesn’t die when temperatures drop below 32 degrees; it goes dormant. Take away one of the ingredients, and mold will not grow

In some cases, mold growth may not be obvious. It is possible that mold may be growing on the back side of drywall, wallpaper, or wood paneling; on top of ceiling tiles; on the underside of carpets and pads; and inside ductwork. If you think you may have a mold problem, consider hiring an experienced professional. It’s also wise to close off the heating, ventilation, and air-conditioning system in that room.

Dry it the right way

Proper drying often involves discarding wet carpet and pads because they trap moisture. If the leak was extensive, it may be helpful to remove the baseboards, because they can trap water.

Try the following:

 Use wet vacuums to remove standing water.

 Set up fans to move air.

 Turn on dehumidifiers to help everything in the area dry faster.

 Call in a specialist in mold remediation, flood damage, and/or carpet drying.

 Open walls and ceilings as needed. You can purchase a moisture meter at your local hardware store. Prices vary from about $30 into the hundreds of dollars.

 Remove and discard wet insulation.

 Throw out anything that cannot be cleaned (materials like moldy carpet and mattresses, for example). Have mold? Before you remove anything, get gloves and protective eyewear. You can get rid of mold in bedding, curtains, drapes, and clothes by washing or dry-cleaning them. If you are taking something out of the house, double bag it so you limit the spread of mold spores. In many cases, what you are tossing can go in your local landfill. Be warned: Removing wallpaper can lead to “a massive release of spores from mold growing on the underside of the paper,” according to the Environmental Protection Agency. Some nonporous materials can be cleaned with a mold remediation product and a scrub brush.

Rules of thumb Y’all know I LOVE them. Here’s a good one: If your house smells moldy, then you probably have mold. Sorry, couldn’t help myself, but it’s true! OK, here’s my real rule of thumb: There are thousands upon thousands of different species of mold. There is no way to tell if mold is toxic just by looking at it. Be wary of any remediation specialist who tells you that you have toxic mold just by looking at it.

As far as I’m aware, unless that person is the “Alchemist of All Molds,” the only way of determining whether you have a toxic kind is to have it tested by a qualified environmental lab. By the way, there are mold-testing kits you can buy and then send to a lab for an additional fee. Many hardware stores carry these kits, and I’m sure you can purchase them online as well.

Dead but still dangerous

“Dead or alive, mold can cause allergic reactions in some people,” according to the EPA.

Want to get rid of it with chlorine bleach? Bleach is convenient and inexpensive but has drawbacks. Its effectiveness in killing mold is significantly reduced when it comes in contact with residual dirt, which is often present in wall cavities, basements, and other areas. Also, bleach water can be corrosive when it comes into contact with electrical components, and it cannot completely kill mold growing in porous materials. The chlorine is left on the surface, and only the water component is absorbed into the material, providing more moisture for the mold to feed on.

The single best method for eliminating these spores in your home is through the use of a certified mold remediation professional.

If you’re a DIY kind of guy like me, you may want to try using a mold-remediation product such as Sporcidin . This brand of products has been used in institutional, commercial, and residential environments for mold remediation and sewage, biohazard, and flood cleanup. I’ve used it on plastic, vinyl, latex, metals, glass, wood, and porcelain products — areas of heavy contamination and staining may be scrubbed with a stiff bristle brush to help speed up the cleaning action and work the product deeper into the substrate. As with any remediation product, follow the manufacturer’s instructions and always wear gloves and protective eyewear.

Rob Robillard is a general contractor, carpenter, and editor of AConcordCarpenter.com. Send your questions to homerepair@globe.com or tweet them to @globehomes or @robertrobillard.
Loading comments...
Real journalists. Real journalism. Subscribe to The Boston Globe today.