Finished Attic Wieght Limit

Stairs can take up a lot of space in both the attic and in the floor below so they are important considerations for planning.

Finished attic wieght limit.

If you care about this you will need to add a second layer of floor joists over the originals perpendicular is best to limit thermal bridging insulate then lay floor over that. It is vital to observe the weight rating and make sure that you comply with it at all times. Modern standards call for around 12 to 16 inches of insulation in the attic and your long term utility bills would probably appreciate it. Building codes typically require that a finished space have a ceiling height of 7 feet 6 inches over at least half of the available floor space.

Your allowed weight and span for a 2 x8 x12 2btr hem fir based on the info you have provided is 20 psf of dead load and 30 psf of live load with minimum bearing length of 0 68. This is because the ladder is simply not strong enough to support any more weight and you are putting unreasonable pressure on the attic access ladders every time you break the weight limit. This is where dreams of adding new living space in an attic are often abandoned. Finished attics need stairs that meet all of the standard staircase requirements.

In general stairs must be at least 3 feet wide and provide at least 6 feet 8 inches of headroom. However if the attic is intended for storage the attic live load or some portion should also be considered for the design of other elements in the load path. To simplify you can place 20 pounds of dead load per square foot on your subfloor as long it s supported mid span. The international residential code on which most local building codes are based requires that floors in non sleeping rooms must support a minimum live load of 40 pounds per square foot and floors in sleeping rooms must be able to handle a live load of 30 pounds per square foot.