Hello,

I Need to install hardwood against nosing on landing between two staircases..

This nosing is 3/4" red oak stained and finished to match the hardwood we will be installing.. Its got a groove that we will install a spline in and contine with the hardwood install...

Problem is, we need to shim a bit next to the nosing so that the hardwood is even... whats the best way to tackle this?

I want to also use some PL under the first board... hopefully to fill the void...

Why are you shimming? Why not sand the substrate flat so no shimming is required?

Because there is no problem wiht the substrate really...
Its more an issue with the actual nosing where its slightly high in the middle... last thing I want to do is have to sand down the nosing, restain and refinish...

Ideas?

So, the nosing is flawed? The nosing does not fit the flooring? Simply return nosing for the correct one. If that is impossible, then are you shimming the nosing or under the flooring that fits next to the nosing? You can use 15 or 30 lb. asphalt saturated felt paper and layer it up as needed. You can glue and staple the paper down if you want. There is no reason to glue the flooring if the slip tongue/spline fits snugly into the groove of the nosing. Simply glue the nose down and top nail with finish nails into the open, darker grain areas. Those hide better when filling. Then glue the spline into the groove of the nosing using yellow wood glue. Shim up the area next to the nosing with the felt paper as need and engage the groove of the first board into the spline. Once fitted, tight and flush, then simply blind nail through the tongue of that first floor board. If the T&G are loose at that joint, either get a spline that fits better or glue the T&G together with yellow glue. You can use the PL if needed. It will adhere to the felt paper and the flooring. Takes overnight to dry.

What I see all the time is the landing is not straight or level so when the nosing is put on the carpenter shims it so it is level probably thinking about building codes, but not taking into consideration how the floor will marry up to it. I would use shims here and there to even it out and you can still use the PL.

is this is a noising that you have put on your self?
If so take it off and sand the top of the riser if the riser is higher in the middle or the ends. or just bite the bullet and sand the noiing flat.
if it was on there it should be a nail on each side of the noiing that you cant see.
Jeff