How to Repair a Crawl Space Joist Rot
- 1). Examine the floor joists in the crawl space to determine the extent and cause of the rot. If the rot is limited to the ends of the joists, then the repair will be relatively simple, by "sistering" a joist on to the side of the existing joist. If the entire joist needs to be replaced due to extensive rot, then the repair will be more complicated. You may need to hire a professional inspector to tell you the extent or cause of the damage.
- 2). Take steps to remove the source of the rot. Make sure the crawl space is properly ventilated, and, if it has a dirt floor, cover it with weed block or plastic sheeting to keep moisture from seeping from the soil directly into the space. Check to make sure water doesn't seep into the crawl space after rainstorms.
- 3). When possible, "sister" new joists side by side onto the existing joints. This is only recommended if the rot is not very extensive and once the moisture problems are dealt with.
- 4). Remove joists that are extensively rotten. Attach new joists in their place.
- 5). Coat all new joists with weather sealant to prevent rot. Make sure to reapply the sealant at the recommended intervals to prevent rot from developing over time.
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