Crawl space liner vs Encapsulation

Friday, November 10th, 2017 by Brittney Gebers

Challenge

A Clarksville home owner called in complaining of what seemed like mold or water smell coming out of the crawl space vents into the house; one room in particular. The home is over 50 years old. They think it may be the insulation under the floors in the crawlspace that's causing the smell.

The home owners had lived here for 23 years and plan to stay forever. They are aware the crawl space leaks and are concerned about the water and mildew. They do not have any mold upstairs now but have in the past. Over the last few years the problem has gotten worse and want to prevent mold and mildew from coming back. The family does suffer from allergies and understands these conditions are a contributing factor to those health concerns.

In a previous attempt a think plastic liner had been placed as a liner on the dirt crawl space floor. However this water proof liner also held liner on the top side, leaving pooled water to linger under the home.

Solution

To start, the old plastic is removed as well as the soiled insulation between the floor joist.

Sister floor joist are installed to run alongside the damaged joist.

Delta Drainage Matting is a dimpled plastic that is laid down on the crawl space floor to allow for ground water movement without pooling under the CleanSpace liner.

CleanSpace liner is a 20 mil plastic vapor barier that will protect the space from leaks and ground water. To make this an encapsulation the vapor barier also runs up the wall is atttached and sealed at the joist.

Sump liner with sump pump are installed to collect and pump water out of the crawl space keeping the space properly conditioned.

An Everlast crawl space door closes, locks, and seals the crawl space off from outside conditions. The non-organic material will not rust, rot, or mold.

Plastic liner holds water in just as well as it keeps water out. The block and brick are porous and allow for water to penetrate and enter the crawl space.

The wood floor joist, temperature, and high humidity create the perfect environment for mold growth.

Wood moisture reading is high at 23.2%. The shrinking and swelling of wood weakens the structure of the home and also contributes to mold growth. These conditions create wood rot which is also damaging to the structure.

With a relative humidity reading of 85.6% moisture in the air is an honest concern for this crawl space.

Encapsulated and sealed the crawl space is conditioned, protecting the home's structure and the duct work. Eliminating drafty floors and cutting back on heating and cooling cost.