per NWFA rules;

1. Wall Line Layout

2. Choose a starting wall according to the most aesthetically or architecturally important elements in the
   room, taking into consideration fireplaces, doors, cabinets and transitions, as well as the squareness of
   the room. The starting wall will often be the longest unbroken wall in the room.

3. Snap a working line parallel to the starting wall, allowing 3⁄4” expansion space between the starting wall
   and the edge of the first strip or plank run.

4. As a general rule, a 3⁄4” expansion space must be left around the perimeter and at all vertical obstructions.

5. Random-width plank is laid out with alternating courses varying by widths. Start with the widest board, then the next width, etc., and repeat the pattern.

   Are you installing rift & qtr?

   *By its nature, wood can shrink and expand relative to the surrounding humidity. The way the annual rings run through the board determines the direction of movement. Plain Sawn will move across the width of the board creating gaps and other problems. Rift and Quarter sawn movement is restricted to the thickness of the board and movement is vertical so the boards are not moving against each other and stay tight. This dimensional stability of each board makes it the best option for radiant heated floors & wide plank flooring.

   The direction of expansion and contraction in the various board configurations is shown below. Note the end grain patterns and how movement corresponds to the grain direction.

   *Allegheny Mt.

   If installing solid floor it is also recommended that it is glued and nailed.

   
   

   
   

Wood expands mostly across the width so if you have to butt a board end into something, it's probably not going to cause a problem.

Is there a reason you dont want an expansion space on the butt ends? It should be covered by baseboard nonetheless.

None. The knowledge that boards shrink very little in length just gives installers flexibility in fitting.

Thanks for the helpful responses. I have one section where the boards will be butting up against my door sil. I am replacing the door in a couple of months and currently the boards go under the sil. Not sure where the the new sil will land so may have to trim back the boards or add a molding depending on where the new sil lands.