These jack posts will be used in my crawl space to reduce floor joist flexing that is causing bath and laundry room tiles to crack. Given the 18,000 lb. load limit, I feel they can easily support 3 joists if I distribute the load across a beam. My crawl space is higher than the 36" range of these posts, but installing a strong pedestal base and using a beam will make up the difference in height. The heavy welded flange plates at either end have several large holes to accommodate anchoring with bolts or lag screws. Product illustrations show these being used with 2 lock pins and 2 holes engaged, but to obtain the full 36" length you will only be able to use a single lock pin hole and the jack threads will need to be nearly fully extended, making for a weaker and less stable installation. But overall, these posts are easily adjusted and secured, and they can support a very large load.