Crawl Space Repair Before & After Photos

A 20 mil vapor barrier is laid, seams are taped, and it is adhered to the crawl space walls, replacing the old and torn 6 mil vapor barrier. Spray foam insulation is installed on the crawl space walls and the sill plate, rim and band, and vents are sealed. 

This homeowner in Richmond, VA called us out to discuss insulating their crawl space. We sent one of our Home Performance Advisors to inspect the situation and found that there was an abundance of mold growth on many of the floor joists in the crawl space. This can occur on any organic material in the crawl space so long as the relative humidity reaches over 60% during warmer temperatures. We used an antimicrobial, called Shockwave, to eliminate mold growth in any affected areas. We also removed the existing liner and any fiberglass batts from the crawl space. This was so we could replace it with a durable 10-mil vapor barrier, called CleanSpace Light, which would protect the crawl space from the earth's rising moisture. The liner gets wrapped around all piers, sealed with vinyl tape, and mechanically fastened to the foundation walls six to eight inches above outside grade. We also noticed that the foundation walls were made with porous cinderblocks, which was allowing the outside moisture to seep through and affect the relative humidity. Open vents lined these porous walls to also allow the outside air and moisture to infiltrate the crawl space. We used custom foam board pieces to internally block off these open vents, then we used Foamax to insulate the crawl space walls. Foamax is 1.5 inches thick, giving it an insulation value of R-10. It acts as an air barrier and vapor retarder and helps to protect the crawl space from any outside influence. Finally, a high-performance dehumidifier called SaniDry Sedona was installed in the crawl space alongside a LittleGiant condensation pump to regulate and control the temperature and relative humidity. A hygrometer was given to the homeowner to monitor this at all times, and they should feel a definite increase in comfort and decrease in energy bills, as their crawl space is now insulated and sealed off from the outside.

This homeowner contacted us with concerns about the joists in their crawl space. At the inspection, we found damaged and falling insulation, mold growing on the floor joists, and high humidity. To mitigate the problems under the home, and prevent them from reoccurring, we sealed the crawl space. The space was cleaned out, the mold was remediated, then we installed a new vapor barrier, sealed all the vents, rim & band, sill plate, and any holes through the foundation to outside. Next, we installed insulation on the foundation walls and installed a dehumidifier to regulate the relative humidity and protect the home from moisture damage. 

Before: The foundation walls of this crawl space are covered in efflorescence, which indicates that water infiltration has been present for this home. Efflorescence occurs when water from the outside seeps through these porous cinderblock walls, bringing all the inner salt and sediment of the blocks to the surface and leaving these stains and marks upon the walls. The water that finds its way into the crawl space can elevate the relative humidity, leading to wood rot, mold and mildew growth, and material damage.

After: The crawl space walls have now been insulated and sealed with Foamax foam board pieces. These 1½ inch boards act as air barriers and vapor retarders, protecting the crawl space from outside influence. They are mechanically fastened to the walls, while the cracks are sealed with can foam. A 2-inch viewing strip is left on the top for termite inspectors, and the bottom is attached to the 20-mil CleanSpace vapor barrier. The crawl space is much more protected from outside air and moisture.

Before: The fiberglass insulation in this crawl space is beginning to fall out of the floor joists, suggesting that there is an excessive amount of water being absorbed by the insulation, making it too heavy to stay in place. Fiberglass acts as a sponge and will pull in moisture from the surrounding air, but the water droplets will pull apart the fibers, and gravity will pull it down in heavy chunks. If the fiberglass has paper-backing, there is a good chance that mold growth will occur, for paper-backed insulation is considered “mold candy” for how easy it is for mold to thrive on it.

After: The crawl space walls have been insulated using Foamax foam board pieces, which are 1½ inches thick, and act as an air barrier and vapor retarder against outside influence. The open vents lining these foundation walls have also been covered on the inside using precisely cut foam board pieces and sealed with can foam. With the walls protected with Foamax, and the dirt floor covered with a 20-mil CleanSpace vapor barrier, outside moisture, and air will find it difficult to penetrate the underbelly of this home.