Today's homes wouldn't be today's homes without LVL or Microllam lumber. This type of structural lumber is so prevalent and indispensable that it's hard to imagine building a home without it anymore.
Microllam is the brand name for a type of engineered lumber made by Weyerhauser and used for heavy structural support. Each piece of this lumber is actually composed of smaller, micro-thin layers of wood that are glued together—or laminated.
Good overall strength
Good weight-to-strength ratio
Good size-to-strength ratio
Special order item
Installation specifications to be followed
While costly, Microllam and other types of laminated veneer lumber (LVL) are today's standard for areas of the home that need heavy support without the bulk associated with older construction techniques.
What Laminated Veneer Lumber (LVL) Is
Much like plywood, thin sheets of wood are sandwiched and bound with super-strong glue. Unlike plywood, Microllam and other LVLs are solid and intended to carry loads.
Different types of LVL can be used either horizontally or vertically. This use is not interchangeable. LVL is specified for its type of use such as for beams (horizontal) or columns (vertical).
LVL has excellent size-to-strength and weight-to-strength ratios. This means that LVL has greater strength in a smaller size than solid lumber. It also means that LVL's is very strong in relation to its weight.
Microlam vs. Microllam
Microlam is a common misspelling for Microllam, a brand owned by Weyerhauser Lumber since 1994. Weyerhauser did use the term "Microlam" for nearly two years until the name was switched to "Microllam." Microlam or Microllam are often used conversationally to refer to all brands of laminated structural support lumber.
If you have an old house and can get in the crawlspace or basement, you will have a good peek at the joists and carrying beams. Unless the home has been renovated recently, no doubt you will be viewing sizable joists: two-by-eights or two-by-tens. Carrying beams, as the name infers, carry huge loads and are serious hunks of timber. In the past, size equated with strength.
But with newer advancements in lumber processing and lamination, manufacturers have been able to produce lighter and smaller lumber with the same or even greater strength.
Without LVL, today's homes would not have cost-efficient open plan kitchens, two-car garages free of center support columns, or extra-wide doorways. LVL makes modern homes possible.
Garage door openings benefit from LVL or Microllam construction because the span is so wide. Running an LVL eliminates the need for a central supporting column for two-car garages.
Uses For Microllam or LVL Lumber
Laminated structural lumber has a wide variety of uses inside and outside of the house.
- Flooring spans in the form of I-beam joists
- Wide windows with LVL as headers
- Doorway headers, especially for wide ones such as french doors
- Garage door openings
- Carrying beams of all types
- Rim boards
- Roof trusses
LVL Installation Specifications
Because LVL lumber is different from conventional dimensional lumber, it installs differently. All brands of LVL lumber come with installation guides that help the installer understand:
- Hole and Notch Spacing: Holes and notches for running electrical cables and other services are usually allowable but only in specified places. The hole size is limited and the number of holes is limited, as well.
- Storage Requirements: Special storage conditions may be required. For example, some LVL lumber is required to be stored in a vertical orientation, not horizontal.
- Fasteners: Certain types of fasteners may be required (or prohibited from use) on different brands of LVL.
- Fastener Pattern: The number, type, and location of fasteners on the LVL may also be specified by the brand of LVL that you are using.
LVL Companies and Brands
Other companies provide structural laminated lumber products, such as:
- Boise Cascade: VersaLam
- Georgia-Pacific: GP Lam LVL
- Louisiana-Pacific: LP SolidStart LVL
- RigidLam LVL
- Universal Forest Products
Cost of LVL Lumber
Microllam and most other LVL runs high per linear foot because of the high degree of manufacturing that goes into each piece. LVL is always a major part of your materials cost for an addition, room bump-out, or wall elimination for an open floor plan home. Sample prices:
- $445 to $500 for a 5-1/4-inch by 13-3/4-inch treated glulam beam
- $30 to $40 for a 1-3/4-inch by 7-1/4-inch by 8-foot LVL beam
- $65 to $75 for a 1-1/4-inch by 11-7/8-inch by 18-foot laminated strand lumber LSL rim board/stringer blank