Subfloor Then Spacers Over Joists Under Flooring

There was never any insulation installed under the floor.

Subfloor then spacers over joists under flooring.

Some experts recommend choosing kiln dried lumber for floor joists. I m putting down a laminate floor over a 3 4 plywood subfloor that is over a unconditioned crawlspace in north florida. The manufacturer of the flooring suggests a 6 mil plastic underlayment for the flooring to block moisture but my concern is the potential for damage to the plywood by locking any moisture in. With the above specs the flooring should be installed perpendicular to the floor joists.

The subfloor is the decking installed on top of flooring joists. It is flexible it can be changed out it is inexpensive. This method of laying a sturdy subfloor on top of joists and then topping the subfloor with a cosmetic only flooring top creates a tighter stronger structure. The finished floor is then installed on top of the subfloor.

In addition be sure to allow the subfloor dry completely before installing any additional top flooring. Uncoupling membranes aren t recommended for tiles smaller than 2 inches square and should not be used when covering old hardwood flooring due to adhesion problems. Always store floor panels under cover. Would 15 tar paper be a viable alternative to use.

Wet lumber may lead to dimensional changes as the joists dry resulting in nail pops and floor squeaks. The vapor barrier is just beneath the subfloor but on top of the joists. The crawl space has a scratch coat of cement on the floor. In basements and in homes with slab on grade foundations the subfloor may simply be a concrete slab.

A 3 4 inch plywood subfloor on a joist structure with 24 inch spacing needs the extra thickness of cementboard or the floor will flex and the tiles will crack. The flooring can be laid parallel to floor joists but you may need to add a 1 2 inch layer of plywood diagonally or perpendicularly to the joists or install a brace between the joists. The subfloor is the foundation beneath finish flooring materials. Avoid using green joists for your floors but instead use sturdy performance tested lumber.

This permits the floor to flex and expand a little as necessary. On wood frame floors the subflooring provides a continuous structural surface over the floor joists. The thickness of plywood panels in a subfloor is regulated by the. Layering makes it easier to change the visible floor if you tire of the look or if it has become damaged.