Doubling Up Every Other Floor Joist

The main reason for doubling up floor joists is to double the strength of a single floor joist.

Doubling up every other floor joist.

After several centuries of service floor joists in older homes may sag or crack. I don t think doubling up a 16 2x8 will all of a sudden span 30. I would think the doubled up s would span further because you can attach one to the other more thoroughly. Long spans of joists in newer homes may wobble or bounce from foot traffic.

I need to put two large velux roof lights 1200 x 1500 in line with each other which means removing two joists and trimming around them. If you double those joists you can span 12 feet 3 inches. This allows you to install continue reading double floor joists. How to make floor joists stronger.

What are they and why use them. If we use strong enough gussets and fasteners we know that the top and bottom joists will deflect by exactly the same amount when loaded. 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. What are double floor joists.

Double floor joists are two joists side by side that are usually nailed or screwed together along the length. To achieve this doubling effect in strength and stiffness you will indeed need to gusset the upper and lower joists together. Does this seem correct please. Therefore following static s advice about doubled up strength if i double up all the c24 47x170 joists to make 94x170 it seems that they should be more than adequate.

Each joist is strong enough to support my weight 175lbs concentrated in a 1 segment of the joist and.