Nailing It Down
By Dave Murnen
and Pat Beaty
A wet, silent predator is consuming our homes.
If you guessed the predator is the ever-falling rain, you were half-right. Our home’s worst enemy is any kind of moisture trapped by insufficient ventilation.
Perhaps that does not sound very menacing to you, but in our years working for Aberdeen Neighborhood Housing Services, we have inspected and directed the rehabilitation of hundreds of moisture-damaged homes. From the foundation to the roof, our inspections have overwhelmingly identified improper ventilation as the common factor in each of those homes.
Much of what you see on our homes—peeling paint, curling shingles, rotted skirting, mold, mildew and bug damage—the signatures of the home predator, can be prevented with proper ventilation and timely maintenance.
There are many sources of problem moisture. Many times we will hear, “Oh it’s Grays Harbor, the weather here is so hard on houses.” It is, but that’s not the only source. Entering our homes with wet shoes, coats and umbrellas, cooking, cleaning, washing, bathing, roof or plumbing leaks, even breathing, all contribute to a high humidity problem.
The good news for all of us is that vents to get this moisture out can be installed in your roof, foundation, bath and kitchen without much expense.
So you are probably wondering: “How do I know if my house is adequately ventilated?”
Our rule of thumb for houses in our area is one square foot of ventilation for every 150 square foot of area. For example, a 1,200-square-foot house, divided by 150, would need 8 square feet of ventilation in the foundation and the same amount in the roof area.
This can be achieved by adding 1- square-foot foundation vents at every corner and evenly spaced around the foundation skirt. For the roof, we recommend ridge and soffit venting. Inside the house you should have a power fan, vented to the outside, in the kitchen and bathroom. By installing these vent types you have taken all the preliminary measures needed for a healthy, breathing home.
In this article, we would like to focus on just one area, the foundation, as a source of moisture.
Let’s begin by describing what we want to see and smell under your house and then what will create problems.
• There should be at least one good access point to get under the house.
• You should have 18-to 24- inches or more space from the ground to the floor joists.
• You should have clean, dry 6-millimeter black plastic on the ground, Laid tightly, anchored at the edges, cut around each pier block and overlapped at the seams, one sheet 12 inches onto the next sheet.
• You should see very few, if any, bugs, spiders or cobwebs.
• There should be no wood-type debris and nothing growing.
• All areas of the foundation, especially under the kitchen and bath, should be dry. There should be lots of fresh air streaming through all the vents and no odd smells, standing water or signs of animals.
• All non-treated wood components should be dry, rot-free, away from soil and separated from any concrete by a felt or composition-roofing barrier.
If you are you wondering what to do if you see or smell some of the things you should not down there, here are some tips:
If you see lots of spider webs, that usually indicates a constant source of moisture. You should put down 6 mil. black plastic tarp and place a splash block at each down spout. Do the formula for ventilation and add more vents if needed.
If you find a water puddle, you need to play detective.
If it is gray, filmy or soapy looking water, it means your sink or tub drainpipes are leaking. You need to operate each fixture, find the problem and repair it.
If the air smells like toilet water, or there are feces and toilet paper on the ground—stop using the sinks and toilet and call a plumber! That water is very hazardous to you health.
Clear water usually means a fresh, constant source. That means you should check your water supply pipes for leaks. If instead it is rainwater, install splash blocks, pipe it or pump it away from the house. Never allow it to go into the City sewer system, though.
If you observe any signs left by critters—urine smells, feces, hair, tracks, the critter!—trap or remove the animal and secure openings in and under the skirt.
Finally, there may be sawdust trails and little holes peppering the wood or larger holes, sure signs of powder-post beetles, ants or termites. You need to get rid of these pests. Depending on the level of damage, a professional pest spray, ventilating to our rule of thumb and removing all sources of moisture will cure the problem. If you wait too long, you’ll have to replace your foundation, sub-floor and skirting.
If you are seeing considerable indications of damage you may need a professional inspection. That is one of the many services we offer through Aberdeen Neighborhood Housing Services.
Do you have questions about home repair or need help in becoming a homeowner? Call Aberdeen Neighborhood Housing Services at 533-7828 or visit us at 710 E. Market St. ANHS is a non-profit organization committed to creating safe and affordable housing for all residents of Grays Harbor County.