How to prevent mold in your attic?

Let's start with the basics. Mold needs three things to grow.

1. Mold Spores

2. Food Source

3. Excess Moisture

You can't control No. 1 since mold grows naturally.

You're probably wondering what kind of food mold likes to eat. Well you can't control No. 2, the food source, since our buildings are constructed with materials that are food sources for mold.

So let's concentrate on the only thing we can control - excess moisture.

What causes excess moisture that enables mold to grow on surfaces within our homes and commercial buildings?

Let's start at the top of your house.

Have you ever gone into your attic and discovered mold? Pretty scary, right.

You immediately begin asking yourself what went wrong? What caused this?

Excess moisture! The No. 1 cause of excess moisture in an attic is elevated humidity.

Attics need airflow. This will help keep the decking dry and keep mold from growing.

What can I do?

Air needs to enter the attic through the soffit vents in the eaves. Unfortunately, many times contractors will stuff the top of the soffits with insulation to prevent heat loss. Bad idea.

Bathroom vents can also be a source of excess moisture. If the exhaust from the vents are discharged into the attic it can provide the moisture necessary for mold growth to occur.

Once the air enters the attic where will it go?

Attic air has to discharge to the exterior.

The most common methods are ridge vents along the peak of the roof, gable vents in the gables, passive vents in the roof and powered fans in the roof.

One or more of these are essential to remove warm, moist air from the attic, thus reducing the No. 1 cause of mold growth - Moisture.

If you find insulation is blocking your soffits just insert these ventilation baffles through the insulation and attach to the decking with staples. Make sure the bottom of the baffle is open so air can flow into the attic.

If your attic doesn't have enough ventilation you can install a powered vent. It is thermostatically controlled to operate when needed.

For larger attics to increase the airflow.

If you have gables and need additional ventilation these vents can be mounted in the gables and thermostatically controlled to operate when needed.

Best installed by those with some handyman skills installing ridge vents are helpful in removing built up moisture from an attic.

Mold cleaners and stain removers

If you do discover mold in your attic, promptly clean the affected areas with a disinfectant and apply a stain remover for a more aesthetic appearance.

Moving down through the house.

Common causes of moisture in the living areas of the home are water intrusion around windows, doors, skylights and plumbing leaks.

Periodically replacing the caulk around these fixtures is a good idea.

Now the bottom.

Basements are often damp. They are built underground so naturally the chance of excess moisture is increased.

What can you do?

Let's start with the most important item you can purchase. a dehumidifier.

Dehumidifiers can help maintain an ideal humidity near 50% in the basement.

You'll want one with a built in pump, if possible, so the dehumidifier can run continuously without needing to empty the condensate collection bucket.

Moisture along block walls can cause efflorescence to form on the walls or possibly even some mold growth. Applying a masonry waterproofer can help inhibit efflorescence and mold growth on the block walls.

What if you have a crawl space?

Damp crawl spaces can provide necessary conditions for mold growth. Mold growth in a crawl space can easily infiltrate into the living areas of the home.

What can you do?

For starters crawl spaces should have a vapor barrier on the floor, and sometimes the walls, to prevent water from getting in. The vapor barrier isn't effective unless it is sealed to be air-tight.

For very wet areas a sump and pump may be necessary to keep water from accumulating under the vapor barrier.

Just like a basement, a dehumidifier may be necessary to keep the relative humidity near 50%.