Joist sizing is based primarily on the span distance between supports and the joist spacing.
Minimum legal height attic.
If staircases are less than one meter wide they should have a handrail on at least one side.
The minimum ceiling height in rooms with sloped ceilings such as a finished attic space is 7 feet over at least 50 percent of the room area.
In an attic room with a sloping ceiling or projection below ceiling line or non habitable room or similar a height that does not unduly interfere with the proper functioning of the room or space.
More than 50 of the ceiling space should be on average a minimum height.
The height of handrails should be between 900mm and 100mm.
With full home additions costing 75 000 minimum and usually far higher many homeowners search for creative ways to increase living space without overly decreasing their bank account.
It s obviously ideal to have even more but that is the bare minimum from a regulatory standpoint.
In a stairway 2 0m measured vertically above the nosing line.
Minimum vertical height of 30 inches measured from the top of the ceiling framing members to the bottom of the roof framing members.
Staircases more than one meter must have handrails on both sides.
Minimum ceiling height for basements with no habitable spaces section r305 1 1.
So what is the minimum height needed.
R304 4 height effect on room area.
Areas with ceilings lower than 5 feet are allowed but do not count toward the official room area total irc.
The access opening should be located in a hallway or other readily accessible location and minimum 22 x 30.
Room area is this case is calculated as the total floor space with walls at least 5 feet tall.
Obviously you need to be able to move around comfortably without having to stoop like the crooked old man who found a sixpence but the fact is that the available headroom or rather the lack of it can usually be sorted out by raising the height of the building or adding a dormer.
One way is by working within the home s existing footprint and converting the attic into living space.
Portions of a room with a sloping ceiling measuring less than 5 feet 1524 mm or a furred ceiling measuring less than 7 feet 2134 mm from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required habitable area for that room.
If the attic space is smaller than these specs then an access hatch is not required.
In other words if your attic has 200 square feet over which the ceiling is at least 5 feet high then for a minimum of 100 square feet 50 of 200 that is the ceiling height needs to be at.
2 x 10 joists spaced every 16 inches can span 13 to 14 feet.
