Reinforcing 2x4 Attic Joists

I need to convert an attic to livable space with minimal disruption to first floor habitation.

Reinforcing 2x4 attic joists.

In the case of 2x6 joists you can pair them up with additional 2x6 joists by nailing them together side by side. Each joist is strong enough to support my weight 175lbs concentrated in a 1 segment of the joist and. 2x10s are the code today. Beefing up attic joists for living space.

Cut a 2 by 4 inch board to match the distance you measured. I talked to a structural engineer and he advised to sister the existing 2 4 joists. Nail the board to the joist and rafter with two nails at each spot. Place the board vertically with the ends overlapping the ceiling rafter and the joist.

Sistering is the process of adding a new joist next to each existing joist. As you can imagine the floor bends a bit when walked on there are tongue and groove planks over the joists in the attic for a floor. Our house has almost exactly the same thing. 20 and are 16 on center.

The existing ceiling joists are 2x6s clear spanning about 11 feet 3 inches. If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists. I want to finish this space with drywall walls and ceiling and also a drywall ceiling in the garage under the joists. There is a 1 2 plywood sub floor on top of the joists.

I have places in the attic where there is a 12 foot span only supported by 2x4s. Each joist is connected by a vertical 2x4 to the roof rafter above it positioned about 4 from the wall. With the 2x4 joists 16 inch centers running the 15 foot width. The attic joists are only 2x4s and are 27 inch on center i double checked.

2x4 s actual size spaced 16 on center running the width of the building uninterrupted with the ends resting on top of the wall top plate. I d like to double my ceiling joists to make my attic space easier to work in for electrical plumbing and for lightweight storage. How to reinforce 2 4 attic floor joists. The type of modifications selected for reinforcing the joists will depend on the recommendations of the engineer but the following methods are commonly used to beef up undersized attic joists.

Plan is to use attic for storage not for living. My ultimate plan is to sister the joists to make a sturdier attic ceiling blow in insulation on the roof and put plywood across the joists for a storage platform for my boxes christmas decorations etc.