Carpentry landing for staircase.

[FredrikR]

As some of you know, I'm working on the basement stairs. I have an overall plan, but I'm currently stuck on the old landing that needs to be expanded and redone...

Down to it will be oak steps similar to the stairs on the right, the green shows how the new should be. About 140 long, 100-110 wide, and 80cm on the far side.

Tips on materials, etc.?

The left part will be freshened up "later". Should I use floor chipboard with an oak surface (countertops from Ikea)?

 

[justusandersson]

Much depends on what the resting plane is supposed to rest on. If there is 100 cm between the side supports, chipboard is less suitable. There is special glued laminated timber in oak for stairs that is thicker (30+ mm) than regular glued laminated timber (for countertops and the like).

 

[FredrikR]

Much depends on what the supporting surface will rest on. If there is 100 cm between the side supports, particle board is less suitable. There is special glued edge oak for stairs that is thicker (30+ mm) than regular glued edge (for countertops and the like).

The existing left part is 50mm tongue-and-groove wood and rests on a frame on the outer edge, it would be possible to add cross-bracing there for something like floor particle board.

Conceptually, it feels difficult to create a new part and join it with the old part on the left.

 

[justusandersson]

I must admit that I don't really understand the situation. Is it an old and a new staircase meeting at the height? The left part also feels very steep. My experience suggests the use of homogeneous materials in stairs, but of course, solid oak can cost a fortune if you don't have access to proper machinery.

 

[FredrikR]

Yes, the old cellar staircase is to the left, then there is a new staircase to the right that weaves together.

The staircase strength you helped me with in the other thread applies to the section with 4 steps down to the landing.

 

[justusandersson]

One option is to buy 18 mm glued wood panels of oak and reinforce it on the underside with furläkt (for the resting surface)..

 

[FredrikR]

I am into something similar with 28mm Ikea oak butcher block.
The small marks are dominoes/biscuits.

Should work, or am I barking up the wrong tree...?

 

[justusandersson]

I amused myself by doing some calculations. Oak has a 20% higher stiffness (modulus of elasticity) than pine and spruce. If you have a 28 mm thick solid oak step with dimensions 60x100 cm that is only attached at its outer edges, a 100 kg person will cause a deflection of 1.4 mm, which I think is completely OK. Glued wood panels should be even stiffer, so I think you can try that. If you glue pieces together with biscuits, I think it can work well.