Glulam Floor System

[Boiler8019]

I always see glulam's being used in roof systems but never for floor systems. It's a straightforward design in the NDS, but I'm not sure how the most efficient framing is typically laid out. Does anyone know of case studies for using glulams in a floor system? It will be an exposed structure from below.

 

[RARWOOD]

It is not very common to use glulam in floor systems in commercial buildings in the Midwest. Glulams are sometimes used for restaurants or retail space in the Midwest. The use of glulams for floor systems is probably more common on the West coast, Contact AITC or APA-EWS for more information.

Glulams are used both with wood decking and plywood with light weight concrete, for floor construction. Typically your beam spacings are 4' to 6'.

If you are using wood decking generally the most economical layout is one where you use 2" decking for both floor and roof construction. Although the use of 2" decking requires closer beam spacings generally that will cost less then a sytsem that uses 3" decking.

 

[Boiler8019]

Thanks RARSWC. The system with 2" wood decking is what I had planned. Is the reason for its rarity because of cost or just the local engineers unfamiliarity with the system? This would be for a church building.

 

[IceNine]

I think since the floor loads will be much larger than the roof loads generally, the glu lam system may get very deep and expensive.

 

[Boiler8019]

As far as depth goes, the glulam beams will be about 30" deep for the 40' span i'm looking at. If that's much more expensive than other systems who knows. Architect is giving lots of space for the structure.

 

[RARWOOD]

In most cases a glulam system is more expensive then other structural systems. However the use of glulams offers asethetic appeal in addition to structural support. Also in many cases the additional cost of glulam over other material is not as large as it appears when the additonal cost of finish material is added to the cost of other systems.

Also as you indicated I think a lot of engineers avoid wood design because they are not familiar with it or they don't like to do wood design. Architects however tend to like wood. Many time the people I work with have to talk an architect back into using wood when an engineer has talked them out of it.