ADVANTAGES OF GLU-LAMINATED COLUMNS OVER SOLID-SAWN COLUMNS
-More complete treating of 1½” thick plies than for solid sawn columns.
-Longer lengths available in high strength lumber.
-Higher quality lumber can be quality checked more closely.
-Any knots are confined to only one ply.
-Lengths of 60 foot or more are possible.
-Usually available within two weeks of ordering.
-Upper columns may be untreated lumber, eliminating the need for hot dipped galvanized nails and making them 15% to 20% lighter than columns that are treated full length, reducing labor and material costs.
-Glu-lam columns remain straight without twisting, warping, or cracking.
-Glu-lam columns allow for windows and doors to fit into the structure better.
-Panelized wall components fit smoothly between or over the planed columns.
-Glu-lam columns are easily incorporated into expanded polystyrene sandwich panels.
-All columns are useable on the job. The labor of sorting crooked and warped columns, and then sending then back to the supplier/yard and waiting for new columns is eliminated.
-Call-backs to replace crooked columns are eliminated.
ADVANTAGES OF GLU-LAMINATED COLUMNS OVER MECHANICALLY LAMINATED COLUMNS
-Lumber can loosen (overcome) nail fasteners as the individual plies twist, warp, or bow.
-Nail laminated column plies will separate if left exposed in yards or at job sites. They should not be stockpiled for long periods of time.
-Nail laminated columns have a lower allowable load capacity than glu-lam columns. As per NDS ’91.
-Nail laminated columns usually use butt joints which reduce the capacity of the column by 33% to 50%, depending upon joint spacing, nailing pattern, and location of splices.
-Mechanical fasteners present a hazard for drills and saws that may be required on the job site.
