Howctovstrengthen Floor Joista

A layer of 3 4 in.

Howctovstrengthen floor joista.

I need to strengthen my floor joist so i can lay a tile floor in my kitchen. With the butt end of the 2 4 against the foundation i worked my way across the floor plumbing the joists and screwing through the 2 4 into each joist to secure them. In the case of 2x6 joists you can pair them up with additional 2x6 joists by nailing them together side by side. Drywall screws through the plywood and into joists.

Lay the new sheets perpendicular to the floor joists and orient panel ends over joists. Notches at the end of the joist should be no deeper than 1 4 the depth. For blocking i ran a 2 4 perpendicular to the joists across their bottoms at the center of the span. If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists.

Step 4 reinforce the floors you will have to use a very sturdy piece of wood or some steel plating to reinforce the floor joists. Add an additional row of fas teners midway between the joists to pull the layers tightly together. As a joist bends downward the lower edge bends slightly to one side or the other. Cut a piece of 2 by 6 or 2 by 8 lumber according to the width.

Your local code will have a allowable live load for attic or living space and multiply by local code safety factor. The reason for the 2x6 is with wires and other utilities i can in most places fit a 2x6 in tight to the floor board. Notches can compromise the strength of floor joists although some notches are acceptable depending on their location as dictated by the international residential code irc. In a perfect world any floor joist that is cut should have a header installed preferably two and doubled adjacent joists.

Place the lumber block between the two joists. A steel plate can be used the same way. Choose ring shank nails or screws that are long enough to penetrate the joists by 11 2in and space them every 6 in. The screws should be no more than 4 in.

Here s a good rule of thumb. Plywood firmly fastened to the undersides of joists helps prevent this side to side bending and stiffens the floor. You then have to find out live load. Is this a waste of money for what i might gain in strength.

The purpose of the headers are to transfer the floor load to the adjacent trimmer joists. Add the floor board and any other dead load which is on the joist and multiply by 1 25 dead load factor or what ever your local code dictates. I ve read about glueing 2x4 to bottom. Beefing up the joists was the only answer.

All headers should be nailed to the cut joists and their ends attached to two adjacent uninterrupted floor joists. My plan is to glue 6 strips of osb to the side of my 2x8 joist then glue and nail a 12 2x6 to the osb. Measure the width between the span of two joists. Now it is time to use some wood and screw it into place on the original joist as well as the cross beam.