H6 -Build Curved Stairs - LT #8 - Flashcards
When is a curved wall required?
As a form for built-up laminated stringers, stepped wall underneath treads & risers without stringers
What is a trammel used for?
To Swing arcs on the floor using the inside and outside radius. Circular saw or router can be mounted on a trammel point.
When using a saw or router on a trammel, where are the dimensions to the center point taken from?
Inside of blade when cutting outside of plate
Outside of blade when cutting inside of plate
What does fair mean, when referring to curved stairs?
Smooth curve w/o bends or kinks.
Why is it important to offset the joints in laminations?
Strengthen joints and even out irregularities.
What is used to form the handrail?
Stair itself is used as the form.
What are the two main ways to build circular stairs?
Treads and risers can be supported with a wall directly underneath the inside & outside of the treads
Stringer attached to a wall, built using curved wall as a form.
The starting point in a circular staircase will typically be:
The header in the floor framing at the top of the stair and a center point for the radius.
Best way to start a circular stairs?
Plumb the header line down to the lower floor level. Extend the line to the center of the circle to establish the centre point.
Mounting a circular saw works best for radius greater than about:
5’
Laminated stringers are at least: 1 1/2’ inches thick.
1 1/2’ inches thick and made from 1/4” to 3/8” thick plywood ripped to 12” or 16”
How are treads supported on circular tringers?
Notched stringers or housed stringers. Using custom made circular saw base jig or routing jig.
How do you frame a stepped wall?
Each stud will be one rise dimension longer or shorter than the next by a common difference.
Why is a sub-tread useful?
Glued & screwed to the framing, can now serve as the wearing surface for any other work to be done during construction, with the finished treads applied later.
