Doubling Up Every Other Floor Joist

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

Doubling up every other floor joist.

After several centuries of service floor joists in older homes may sag or crack. 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. Double floor joists are two joists side by side that are usually nailed or screwed together along the length. If you double those joists you can span 12 feet 3 inches.

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. Why would you use a double floor joist. 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.

I don t think doubling up a 16 2x8 will all of a sudden span 30. What are double floor joists. To achieve this doubling effect in strength and stiffness you will indeed need to gusset the upper and lower joists together. The main reason for doubling up floor joists is to double the strength of a single floor joist.

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. Does this seem correct please. Not even a 12 micro will span that far. How to make floor joists stronger.

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.