Chapter 22 – Inspecting Sub-Areas & Crawl Spaces
We will continue our inspection with the sub-area and crawl space.
Unless your home was built on a concrete slab it will have a sub-area or crawl space.
I found issues in the crawl space even in the best kept homes. This is probably because most people prefer not to enter this area, even if there is enough room to stand.
Sub-areas can be tight confined spaces with only a few inches of clearance between the soil and floor joists or they can be open expansive spaces several feet high. Whether you choose to inspect this area is your decision.
There are various aspects to be investigated in the crawl space including: the foundation system, proper installation of the insulation, crawl space ventilation, dryer vent ducting, HVAC ducting, water heater bracing, water supply and waste plumbing pipes, electrical items, soil condition and excavation issues.
Access to the crawl space can vary from a trap door hidden under carpet in a bedroom to a full size door at the exterior of the building. Ideally, this access opening will be at least 30″ square.
If you see standing water in the opening of the crawl space, STOP!!
Text Repeat:
DO NOT ENTER THIS AREA UNTIL YOU KNOW THERE ARE NO ELECTRICAL WIRES LYING IN THE WATER. CONTACT A LICENSED ELECTRICAL CONTRACTOR FOR FURTHER INVESTIGATION.
IF WATER IS THE RESULT OF A SEWER LINE LEAK, YOU MUST NOT ENTER THE AREA. SEWER LINE LEAKS CONTAMINATE THE BREATHING AIR.
If you are able to safely enter the crawl space your inspection will include examining the perimeter of the foundation for cracks or damage. Put on gloves, a mask or respirator, kneepads, elbow pads and goggles or protective eyewear before you enter the crawl space.
Inspect the piers and posts to insure they are making good contact with the beams they are supporting.
The home inspector will be looking for excessive cuts and holes in wood construction components. There could be several reasons why the joists and beams under the building have been cut. One example is when a plumber bores a hole to fit pipes and waste lines. Sometimes an HVAC installer will cut a floor joist rather than reposition a heater floor register.
If you recall the discussion on “span” in an earlier chapter, you received a brief education on wood span issues. The underside of your home is constructed of several components that make up the support system and floor of the building.
Beams and joists are the primary components that cross back and forth under the building to create the floor and tie the exterior walls together. Builders and architects follow specific tables to know what material types and sizes can be used to “span” certain distances and still support the structure above.
Let’s have a look at our span image again. The lower drawing shows excessive stress being placed on the beam. What do you think would happen if I cut holes in the board at those areas indicated by the arrows? The larger the holes, the quicker the board will fail.
Holes and notches are allowed within very specific tolerances and in a few locations along the beam or joist. Here is the rule of thumb:
Holes: Do not bore holes closer than 2″ from joist edges, nor make them larger than 1/3 the depth of the joist.
Notches: Do not make notches in the middle third of the span where the bending forces are greatest. Notches should be no deeper than 1/6 the depth of the joist. Notches at the end of the joist should be no deeper than 1/4 the depth. Limit the length of notches to 1/3 of the joist’s depth.
Boards with holes or notches exceeding these limits must have additional construction members installed to redistribute the load the board is supposed to support.
No wood component of the foundation, flooring or support system should be in contact with the soil. No wood materials stored in the crawl space should be in contact with the soil.
The insulation material should be properly installed and securely fitted.
Proper installation of the insulation in the crawl space has been a controversial issue from time to time. The most common insulation material used in the crawl space is rolled fiberglass batting with a facing. The facing or material coating is foil, plastic or kraft paper. The facing is also referred to as the vapor barrier. Batting in attics is often unfaced.
On many occasions I observed insulation material in the crawl space where the vapor barrier faced downward toward the soil. I reported the insulation was installed upside down.
That report note often generated phone calls from owners and Realtors informing me their licensed contractor said it was installed properly. I had a conversation with a contractor who told me I was wrong and that I should find another line of work. He told me the vapor barrier was to block the vapor that was being released from the soil. After three or four of these episodes, I decided to get the final word on the issue.
I spent several hours researching this subject. Here is a very condensed version of my findings:
In climates of low humidity, the vapor barrier is always placed toward the heated living space. In walls, the vaporbarrier faces inward toward the room; in attics, downward to the rooms below and in a crawl space, upward toward the rooms above. The warm moisture generated inside a building will naturally migrate to the colder surfaces and exterior walls and floor. The moisture can and does penetrate through floors and walls. The vapor retarder (barrier) essentially prevents the moisture generated inside the building from getting trapped in the insulation material where mold and fungus can grow.
In warm climates with high humidity, the denser moisture laden air will migrate towards the conditioned dryer air inside the building so the vapor barrier is installed away from the conditioned living space. The reason is to prevent moisture from getting trapped in the insulation batting, which will reduce its effectiveness. This also prevents the growth of fungus and mold.
In my region of the country, the vapor barrier installed in crawl spaces faces toward the living space above.
Termite contractors will recommend and install a plastic moisture barrier over the entire floor of a crawl space. This barrier traps moisture coming from the soil. This practice is useful in chronic damp conditions and lowers the potential for mold and mildew.
Open crawl space foundation vents provide a cross flow of air and are essential for maintaining low levels of moisture. The vents should be screened to prevent the entry of vermin and should not be blocked. The foundation vents can also be inspected from the exterior of building.
Another source for moisture is the clothes dryer duct pipe. The dryer ducting should be properly secured to the floor joists, not have any sags, not be damaged or disconnected in any way and terminate at the exterior of the building. Dryer ducts over 20’ require a booster fan to exhaust the moist air.
DISCONNECTED DRYER VENT DUCTING DISCHARGED INTO THE CRAWL SPACE MAY ATTRACT TERMITES.
SAGGING AND DAMAGED DRYER VENT DUCTING MAY CAUSE OVER HEATING AND BECOME A FIRE HAZARD.
Check the HVAC ducting of the central heating and cooling systems. Make sure that all ducting is suspended above the ground, is secured to the floor joists and that all wyes, boots and sheet metal joints are attached and insulated.
Clear soil and flammable materials away from the water heater and furnace. Insure the water heater and furnace are properly braced.
Inspect the plumbing water supply and waste lines for damage, leaks and proper installation. To help identify water leaks, run all the water faucets, toilets and showers in the home before inspecting the plumbing and waste lines. The trick is to look at the ground beneath the pipes for wet spots or mud. This will give you a clue as to the condition of the plumbing joints.
There are charts that instruct building contractors on how often certain pipes should be supported to prevent sagging. For your inspection, if a pipe or waste line looks like it is sagging it needs more support.
Inspect the electrical components. The crawl space often has open splices, missing junction box covers and wires that seem to go nowhere. Use the non-contact voltage tester
Remove all debris from the crawl space area. Debris is anything made of cellulose material that attracts termites and other pests. Cardboard boxes and wood sitting on the dirt are huge red flags for termite contractors and home inspectors. A way to impress the termite contractor and the home inspector is to rake the soil in the crawl space. Leave the lines made by the rake. This is very cool.
The exterior grade slope and landscape irrigation practices can have a huge impact on the dryness of the crawl space. Record any signs of moisture or any place where water appears to have been flowing.
The home inspector will look for areas of over-excavation of the soil. The foundation, piers and posts and retaining walls require support from the earth in order to support the structure above.
In the mountains where we work and live, many homes were built on a hillside. These buildings often had expansive areas underneath. We found homeowners who had altered this sub area for storage. In order to have a nice flat floor they would remove or “excavate” excessive soil around the foundation, stem walls and support posts.
Another common practice was partially enclosing the sub area for additional living space. This presents problems such as: floor joists and wall components in contact with the soil; inaccessible crawl space under the new room; compromised ventilation of the sub area and excessive excavation of the soil.
It was unknown if these rooms were constructed under permit but the biggest issue was the installation of access stairs from the floor above. I am not sure how a person can think it is ok to cut out several floor joists for a stairway and not properly support the floor.
Such practices compromise the foundation of the building and will always generate a note in a home inspection report. The note will recommend that a licensed Structural Engineer be called to evaluate the changes. Nothing will raise the hair on the back of a Realtor’s neck faster than calling for an engineer’s evaluation. The need for such an evaluation usually indicates a serious problem, and such problems may jeopardize a smooth close.
______________________________
SUB AREAS AND CRAWL SPACE FINDINGS: REMEDIES AND SOLUTIONS
Broken, damaged or deteriorated framing members should be inspected and repaired by a licensed contractor.
Hairline cracks in the stem walls of the foundation are not uncommon. Unless they are shearing (twisting in different directions) or are large enough to fit a nickel in the crack, concern should be minimal. A licensed Structural Engineer would need to provide additional information.
Insulation that has been damaged or is hanging down should be secured or replaced. Open up blocked foundation vents and repair or replace damaged foundation vent screens.
Secure or repair damaged or detached heating and dryer vent ducting.
Brace the water heater. Clear away soil from the water heater and furnace housing. In California, it is state law that the homeowner must brace the water heater before the close of escrow. Check with a local plumbing company or your municipal building department to learn the necessary requirements for your region.
Hire a qualified tradesman to repair water leaks and electrical issues. Splices should be in junction boxes and open junction boxes should be covered.
Dampness in the crawl space soil may be a seasonal condition. In some areas, naturally occurring moisture in the ground is normal. Plastic sheeting set on the crawl space floor is a common way to trap and retard condensation issues and reduces the potential for organic growth.
The source of muddy, standing or running water should be thoroughly investigated. Excessive water intrusion can be detrimental to the integrity of the foundation. It can also cause deterioration in the wood underpinning. If it is determined that the water is coming from an underground source and is more than seasonal, a sump pump or “French” drain may be a necessary. Contact a Geotechnical Engineer to determine how best to address this issue.
Excessive excavation issues can usually be resolved be supporting the soil with retaining walls. Questionable construction practices can be looked at and repaired without necessarily calling in a Structural Engineer. A good contractor can determine a reasonable course of action for repairs. Let the contractor call an engineer if needed.
PHOTO GALLERY
An additional 86 images with descriptive captions are available in the 27 Dollar Home Inspections eBook.
Click here to move on to
Chapter 23 – Inspecting Pools, Spas, Alarm Systems, Telephone Service. etc.
