Cutting a stair stringer - GIF

[mwmkravchenko]

I conjecture that the risers and treads will be covered with the composite material, overhanging the cut edges, with sealant applied to the joints, before erecting the balustrade game. I suppose the purpose of the video was to show how a spiral bit in a router can be made to follow a line. Surely that softwood is not for outdoors?

You are right about the main purpose of the video. The shielding idea is also a good one. The plastering spatula id maybe 0.3mm thick.

As for softwood on exterior structural work. That is in the USA. They use a type of pie that is called broad leaf pine. It is rather hard. The Northern USA and Canada use spruce for structural work. Exterior structural work is best done with wood pressure treated for fungal mold and insect infestation. If you follow true carpentry methods it is strong enough for the applications. The stairs shown have a rather limited lifespan due to the only thing holding the treads in place is the shear strength on the few screws on either end of the tread. I don't consider this carpentry.

[Philip Davies]

Not what we in England would call a “proper job”!