The Green Gobbler

Part six of this do it yourself home energy audit series takes you through the audit of your crawl space.

To this point we’ve walked you through the basics of the tools, safety, systems, mechanics. We like to be pretty darn thorough, so in the spirit of going through your home from top to bottom, leaving you last time with how to go through your attic and insulation, now we will discuss how to do your own audit of your basement crawl space. Note that homes is closed crawl spaces (conditioned crawl), typically save more on energy when compared to homes with wall-vented crawl spaces.

Here are the things you should look for for per Crawlspaces.org in order to have good design of a crawl space:

Moisture management- roof run off directed away from the house, site grading directs surface water away from the house, etc. More will be touched on in the next series.

Pest control-termite inspection gap, batt insulation in the band joist.

Combustion safety-combustion appliances correctly installed and appropriately vented per manufacturers specifications.

Fire safety-air sealing of penetrations with non-porous materials, documentation of fire rating of exposed foam insulation, if applicable

Thermal insulation- insulation at the sub-floor or at perimeter wall to provide R-value required bu the local residential code. Insulation at the sub-floor installed without gaps or compression and in full contact with the sub-floor to achieve nominal R-value; insulation on crawl space access(es) of minimum of R-2.

Radon control- In areas where radon is a risk or where the local residential code requires control of radon or other soil gases, houses with closed crawl space foundations can be tested, monitored and if necessary, mitigated with the same techniques used for houses with a slab or basement foundation in the same region.

When you get your access into your crawl space, remember you will want to be wearing clothes that you don’t mind dirtying and possibly ripping, as you might have to do so- ahem… crawling. Take you flashlight and a measuring take or ruler so you can measure the insulation in your floor joists. A crawl space is much like an unheated basement. You will want to inspect your insulation levels and make sure it is installed correctly. While you’re in there, see if you can do the same game you did in the attic… find hole, fix hole; if you find a hole from the crawl space to the living area, seal it with a spray foam or caulk so that you aren’t pulling in damp air from your crawl space into you living area. Also, make note of any areas where there is sitting water, or where the ground is considerable more damp. Take a look for any leaking pipes while you’re down there! If you take away one thing from the inspection of your crawl space, you should have a fully sealed vapor retarder on the floor and perimeter walls to reduce evaporation of water into the crawl space. Crawlspace.org suggests a “6-mil un-reinforced polyethylene ground vapor retarder to avoid damage in areas that may require service equipment.”  Most crawl spaces in Northern Virginia will be where pipes are below the house. If the crawl space is an un-vented crawl space, you could be likely to collect bulk moisture in your crawl space, which could be a potential mold hazard. In this instance, using a mechanical drying system to reduce humidity would be a good option for you in your crawl space. It is easy to find water alarms to inform you of water build up in your crawl space; these “waterbugs” can save you thousands of dollars if you hear an alarm go off when they immediately sense bulk moisture in your crawl space.

You’ve gone through your house from top to bottom, attic to basement, HVAC to hot water heater. Now it is time to think about the exterior. Next time, we will chat about moisture management. We hope you’re having fun with your do it yourself home energy audit! Spread the word! Ask us questions!