Sheri’s Blog

Dear Homeowner,

Have you noticed…

• Small cracks in the drywall above windows and doors
• Small cracks in the exterior brick motor
• Funny smells
• Floors feel a little uneven
• Sound of water dripping in the walls
• Allergies flaring up (nose running, eyes watering, etc.)

These are my invitations to come visit me, your crawlspace. I know you probably don’t want to visit me anymore than you do the dentist, but you need to, before the pain gets bad- maybe real bad.

When you come in and visit, you’ll need old clothes and a good flashlight, because I have a lot to show you. You might want to bring a camera, too! By the way- entering the crawlspace is not for everyone- so proceed with caution, and at your own risk. If you are not up for it, hire a qualified Home Inspector.

Let’s start with the floor joists over your head- the heavy wooden beams that support the floor. There are a lot of them- and they are very important. You need to look at both sides of each joist, to make sure there is no fungus growing on them. If you are not sure what fungus looks like- but see any kind of regular pattern of spots, you need to call an expert.

While crawling around to look at the joists, it is important you look for the major cause of damage under your home- MOISTURE. Moisture can come from a variety of sources. Here are a few

• Cracks in the foundation
• High water table, underground springs, runoff
• Roof leaks
• Leaking water or drain pipe
• Condensation on AC ducts

If you do find moisture, or evidence of puddles of water, remember that the source can be above you, below you, or from any side. If rain related, and it has not rained for a while, pretend you’re the mars rover, looking for evidence of water, and where it came from.

An extremely common source of crawlspace moisture, in our humid southern climate, is condensation from the AC ducts. Some “solutions” to keep the crawlspace dry, like powered ventilation fans, actually exacerbate this problem by increasing the air flow over the cold duct, increasing the rate of condensation, thus generating more water. The typical solution to this: an electric de-humidifier is placed under the house, and powered fans are turned off.

If water is entering the crawlspace thru the foundation wall or soil- ideally it should be externally blocked and rerouted away from the crawlspace. Sometimes this can be a simple matter of adding hoses to the gutter down spouts. Other times, you will need to install external French drains around your foundation (trenches with corrugated pipe and gravel) to reroute this water.

If water the source of the water entering the crawlspace cannot be identified and blocked, the typical solution is to add internal french drains and a sump pump to extract any water which gets inside. The French drains will all lead to a sump pit, with the sump pump at the bottom.

While in the crawlspace, you should look at your AC ducting. Over time, the tape used to secure the ducting together can fail, leading to leaks. Crawling around can also damage the ducts, so be careful. If you have a leaking duct, this can cause two types of problems. If the leak is on the suction side (the large duct from the return inside your home to the main air handler), you will be sucking crawlspace air into your home- which can be unsafe. More commonly, the leak will be on the distribution side- blowing cold air from your house into your crawlspace. Both types of leaks will cost you for the extra electricity used- but the suction leaks can make you sick too.

Finally, you’ll need to take a look at your foundation. The thing to keep in mind here- if you have cracks in your drywall or brick work, something in your house has moved. There is always going to be some movement of your house- as the temperature and humidity change, materials expand and contract. Don’t be concerned with hairline cracks- but watch them. However, if you can insert something into the crack- the movement is probably due to a shift in the foundation- and should be checked out.

Typically, the foundation walls have a poured cement footer, 18” wide and 12″ deep, which is buried and cannot be seen. On top of the footer, cinderblocks make up the majority of the foundation wall.

If the foundation was waterproofed by the builder, the color of the cinderblocks should be a consistent light gray. Color variation is a sign of moisture. Exterior foundation waterproofing is common in today’s construction, but was not in the past- so it is normal to see some discoloration- and if you don’t have signs of moisture problems, you probably don’t need to worry about it. While looking at the foundation, keep an eye out for termite tunnels.

If you see cracks in the cinderblock motor and/or significatnt discoloration, have a foundation repair company come out and take a look. If needed, they will hand excavate under the original foundation, and poor a “sub foundation” under it to add support.

Piers, the internal foundation supports, should be visually inspected for cracks in the motor, or any lean. If built correctly, the piers should be centered under the beam they support, and should be straight and plumb.

In closing, two other things to look for: Is the vapor barrier (plastic sheeting) completely covering the ground, with overlap at the seams and no holes or gaps? Ideally, the vapor barrier has been run about 12” up the foundation wall, and was tacked in place with wood strips- the purpose being to keep the water under the barrier. Gaps in the vapor barrier can allow Radon gas and moisture an easy path into your crawlspace.

Well, by now, you are probably ready to have a look- or hire a professional. Hope your crawlspace is clean, dry, and stays that way.