Span calculator for wood joists and rafters also available for the android os.
Flooring deflection 2x6.
Dead load weight of structure and fixed loads 10 lbs ft 2.
The dead load on a floor is determined by the materials used in the floor s construction.
So consider a simple gable roof on a 24 foot wide ranch framed with 2x6 exterior walls and a 1 1 2 ridge.
Boss hog has instructed us that the feel of a floor depends on its resonant frequency as well as the the actual deflection.
The span would be 11 5 3 4.
If there s wall board covered ceiling suspended from the underside of that floor the dead load increases to about 10 pounds per square foot.
By doubling up the joists we cut their deflection the distance they would bend under weight in half.
Check your code and.
Enter your floor joist information and then hit calculate deflection to find out your floor rating.
For example the allowable deflection of a 12ft span floor joist with plaster l 360 is 0 4 12ft divided by 360.
See the table below.
1 psf lb f ft 2 47 88 n m 2.
Again deflection varies as the inverse of stiffness so the deflection of a 2x6 and 2 8 sistered together is 1 3 5357 2828 relative to the deflection of the 2x6 alone for a 71 72 reduction.
Live load psf dead load psf span calculator for wood joists and rafters available for the iphone.
A typical wood frame floor covered with carpet or vinyl flooring has a dead load of about 8 pounds per square foot.
If there is any deflection in the subfloor when walked on it would be advisable to add an additional layer of 3 8 or 1 2 thick plywood underlayment glued and screwed down over osb subfloor to add stability or install 2x6 blocking between the floor joists for added stability.
Ft plus any long term deflection due to the weight of the floor.
If you have engineered truss or i beam type joists please do not use this calculator.
For example the maximum deflection for a joist span of 15 is 15 12 360 1 2.
Working in the unfinished basement below the bouncy floor we had to remove the plumbing and electrical lines running through the joists and then rerun the lines after the new 2x10s were in place.
Live load is weight of furniture wind snow and more.
Spacing in exterior exposure.
Note it gives the allowable deflection based on a fractional span quantity so a larger denominator will yield less deflection.
Ceiling joists are sized like floor joists except that deflection limits vary depending on whether the joists will be used for attic storage or will have a plaster or drywall finish.
If that same joist had gypsum ceiling l 240 the allowable deflection is 0 6.
Divide the total span of the floor joists in inches by 360 to determine the maximum amount the floor can give in the middle under a live load of 40 lb sq.
1 ft 0 3048 m.
Maximum floor joist span for no.
