Joining wood planks together on stairs

[Zack Lancaster]

I will be tackling my little stair project over the weekend and had a couple questions about the stair I am doing.

1.) Joining my wood planks together. My bottom step is a wedge shape and is about 18 inches at it's deepest, so I will be needing to use three pieces of wood since the stair treads I bought are only 11 and 1/2 inch deep. That said, what is a good way to join these together before I cut them to the wedge shape. Lap joint? Biscuit joint? Some other joint I probably can't do? ;)

2.) The stair has an angle cut as well on the front... so I need to join another piece to the 2 straight pieces I am going. How best to measure and apply the angle correctly to my boards so I can get the angle correct?

Also I have to update: I made 2 circular saw jigs since my table saw is CRAP, and it works GREAT! So cutting the boards, including the nose off the one tread, should prove quite easy.

Thanks.

Zack

[Zack Lancaster]

For the record - I am hoping you say half inch lap join so I can use my fancy new router bits. ;)

[Peter Quinn]

For the record - I am hoping you say half inch lap join so I can use my fancy new router bits. ;)

Sorry to disappoint....for stair treads, the pie shaped kind are called winders...long grain to long grain requires no joinery beyond a good glue joint. Make the edges meet well with a jointer or plane as for any panel glue up and clamp them hard. The glue will do the joining.

[Jim Matthews]

Treads should have parallel top and bottom faces.
The edge between each board should be
perpendicular to these faces.

A simple glued rub joint will do.

The more material you take away to make these two joints,
the weaker the stair will become.

In this case, simplest is best.

[peter gagliardi]

As Peter mentioned, accurate edge prep is all you need. However, it appears you are saying the tread will have a full length back edge, and you will cut the " pie" or angle on the face?
This is exactly opposite of a properly executed stair tread.
Always, always, the front of tread has full length edge grain, the angle or "pie" cut is to the back.

[Bill McNiel]

My approach-
The grain should run parallel to the risers in both the front and back of of the tread, this visually adds to the "winder look". This means that the three pieces that will be joined together will all be "pie shaped" and similar in width.

Easiest way to joint the boards, assuming you do not have a jointer or hand plane skills, is to rough cut the angle and then clamp down the boards so the mating edges are butted together and then run your guided circular saw along the joint so that both boards are cut at the same time. This will create a near perfect glue joint line. After glue-up, trim the tread to fit.

Have fun and enjoy.