Add Bridging Attic Joist

Affix rigid foam insulation to the attic side of the hatch or door.

Add bridging attic joist.

Start by making sure the original bridging is tightly fastened. Add weatherstripping around the perimeter and a sweep to the door of a walk up attic. Use a zippered insulated tent to keep the enclosure draft free attic tent at 7 attic cover insulator 120. Bridging or x bracing allows joists to share weight.

Divide the span by three and add rows of bridging at both of the one third points. Installing flooring material over the attic doesn t quite leave room for the recommended insulation space needed to provide efficient home energy. Toenail the blocks or end nail through the joists to tie everything together. Cut and install lumber blocking or bridging between the joists if required by local code.

Attic hatch or door. Pull down stair or ladder. Floor joist bridging is critical to the structural strength of a floor as shown in figure 1. Measure the width and length of the existing joist.

Put 2x8 blocks at the third points set at the midheight of the assembly and bridging the horizontal joint between top and bottom joists. If the existing joist system is very close to being sufficient to support a new attic flooring the addition of bridging between the joists may be all that s required. Yet it is not uncommon to find bridging not properly installed or missing all together. Once the structure has passed the building inspection you can run electrical plumbing and mechanical lines and insulation as applicable then install plywood subflooring.

What i would do is to add a 2 4 to the top and bottom of each joist using glue and structural screws to convert each joist into an i joist in place piffin writes. A raised platform of lumber in dimensions of 2 4 or 2 6 with insulation placed between joists and covered up with a 12 inch plywood helps build the right flooring. Purchase the type of lumber that matches the width of the existing joist. Most new construction uses 2 by 8 lumber for joists although 2 by 6.

You could even possibly introduce a good crown to each by holding the bottom chord in place with a slightly long 2 4 post under the center as you install it. Each piece of bridging requires four nails two at each end. Add nails or screws if necessary.