There are many variations of wood used for glu-lam products. Typically, SYP and Doug Fir are used for their strength and beauty. These may be treated or untreated. Doug Fir must be incined to treat which leaves marks on the surface. Cedar is often used in lieu of a treated product for exterior use and also for its beauty and aroma. Red Cedar, Alaskan Cedar, etc. are common types used. Hardwoods such as oak are often used because of beauty and durability. Hardwood products require special attention such as pre-drilling for even nails, screws and small lag bolts. They also are not treatable so must be sealed and protected from excess moisture. Spruce Pine Fir (SPF) is often used for lower stressed beams and columns and is often used for the middle section of beams with high strength plies on the top and bottom. SPF does not treat well.
- Glu-lam members are substantially stronger than sold sawn members.
- Large solid lumber beams must be cut from large trees. This limits the supply to older trees of which there are fewer and fewer around.
- In a solid beam or column, any knot or other anomaly usually runs through the entire member. When this is near the edge, the member is substantially weakened. Since glu-lam member plies are randomly assembled, these anomalies never continue through the entire cross section.
- Solid sawn members are prone to twisting, splitting and warping when drying out. Glu-Lam plies are all kiln dried prior to gluing to within a few points of equilibrium moisture content of the structure they will be placed in. Also, the grain patterns oppose each other and therefore hold each other straight.
Face checking may occur in glu-lam products but it is never a structural problem.
If the product is manufactured under the supervision of a third party group such as APA EWS or AITC, they meet ANSI A190.1 standards and thus meet IBC & IRC and most state specifications. Therefore they should be accepted by all building officials. On a rare occasion, an inspector, who is not familiar with glu-lam products wants to communicate with a structural engineer registered in the state the project is in. Gruen-Wald provides this service for you. On rare occasions, elaborate calculations may require added fees, but very seldom does it become this extreme.
There are wood frame structures in existence that are over 1500 years old. Many European cities have 1000+ year old structures. If properly maintained, a wood structure will typically outlast steel and concrete structures.
Is it environmentally friendly to use wood instead of steel, concrete, recycled plastics or other such products?
Wood is the only truly renewable resource to use in buildings. More trees are being planted each day than are being harvested (about 6 to 1). These beautiful living organisms remove carbon from the atmosphere, store it in their fibers and breathe out pure oxygen. Then, when harvested they store tons of carbon for the life of the structure. If the structure is to be demolished, these wood members may be recycled and used to build another structure.
- Wood is the most efficient product of all other typical products.
- Wood compared to steel, concrete, aluminum and recycled plastics has the smallest carbon footprint!
- Wood structures are also superior for insulative properties.
We have done up to 120’ spans for trusses but typically they are practical to 100’.
Manufacturing usually takes four to eight weeks depending on the size, complexity and erection is generally 1/3 to ½ the time for other construction. For example, a 4 story, 12,500 square foot heavy timber frame house was erected in two weeks of working time with 3 laborers and a crane operator using SIP panels for walls and roof.