Osha standard 1910 27 for the safe design and load requirements of fixed ladders appurtenances and fastenings.
Osha roof ladder.
For starters prior to the new ruling the only real guidance on fixed ladders came from the construction standards osha more 1926 1053 a 18 required the use of cages wells ladder safety devices or self retracting lifelines for fixed ladders of 24 feet or more.
Ladder rungs steps and cleats have a minimum clear width of 11 5 inches 29 cm on portable ladders and 16 inches 41 cm measured before installation of ladder safety systems for fixed ladders except that.
Per osha 1910 23 d 4 the side rails of through or sidestep ladders must extend 42 inches above the top of the access level or landing platform served by the ladder.
You can choose any pfas provided it meets the osha requirements in section 1926 502 d.
Fixed ladders shall be provided with cages wells ladder safety devices or self retracting lifelines where the length of climb is less than 24 feet 7 3 m but the top of the ladder is at a distance greater than 24 feet 7 3 m above lower levels.
A ladder that is less than 24 feet high does not require a fall arrest system of any sort.