wood building drawing grids

[Taro]

Where is the most practical location to set building grids on plan drawings for a wood bearing wall building, and why? Centerline of wall, face of stud (exterior/interior), face of sheathing, other? The building will have both exterior and interior walls.

 

[steve111]

set your grid for the concrete foundation. if it's residential framing use o/s of foundation wall, off set wood framing from this. if you have pilasters, interior piers and spread footings then centerlines/grids of these. Framers will want o/s faces (sheathing) of exterior walls, and distances to faces of interior stud walls. very rare to see grids on residential wood framing. if the foundation goes in correctly thats 90% of the dimension game resolved.

 

[Taro]

I guess some clarification is needed. The project is not residential, it's a 20,000 SF commercial building. Glulam custom roof trusses and no interior columns or isolated spread footings. Only bearing walls exterior and interior.

I have always set grids at face of studs, for both exterior and interior walls. The architect on this project usually sets interior grid lines at centerlines of interior walls. Just wanted to see if anyone had any good reasons for doing it either way.

 

[JAE]

We've had a total argument with our architects on this one. Not so much with "gridlines" but with dimensioning. They want to dimension to finish face of walls while we want to dimension to face of stud.

Their argument: We need to set corridor widths, clearances and simple-finish distances to line up with ceiling grids, doors, etc. If we dimension to face of stud, we have to add small, cumbersome dimensions to our drawings and that's a lot of work.

Our argument: Dimensioning to the face of gypsum board or to dryvit is ridiculous as the contractor must first build the studs and footings in the first place. If you give him the finish distance, he has to do field math with fractions to lay out his walls.....pretty risky.

Architects design spaces....engineers design the material that encompasses the spaces....we each come from two different directions and thereby tend to want two different means of getting to the finish line.

 

[engrx2]

I've always dimensioned to outside face of wall on framing plans and to outside edge of trench footings for foundations. If any columns are present, I always have the architect or myself set up grids at column centerlines. This is useful for column footings and any necessary baseplates.

 

[steve111]

exactly correct all the messages, as replied. Columns, built up columns, any principal structural members should be centerlines of members. all walls should be outside faces of framing, which if the wall is sheathed should include sheathing (as they build the wall on the ground and flip it up and push the wall to the chalk line snapped on the foundation wall or slab) and if unsheathed to the face of the stud.

 

[dik]

If an architect is involved, we usually let them set the gridlines and dimensions and use these. The contractor can establish the dimensions to structure... Often projects are revised and dimensions are changed... and the responsibility for dimensioning and coordination is with the Architect and Contractor (actual design is based on dimensions calculated to structural elements and significant dimensions are added to the plans when necessary).

If no architect is involved, then we usually use face of wall or centre lines of columns for gridlines and dimensions. For small lumber framed residential projects, I've often come across plans where dimensioning is to centreline of partitions and bearing walls.