Light Wood Frame Construction Framing Methods Floor Systems Wall Systems Roof Systems Wood Terms IBC - Type 5 Construction Professor Richard Luxenburg, AIA Anne Arundel Community College Department of Architecture and Interior Design Fall 2009
The true measurement of a 2x4 is actually about 1.5x3.5. When the board is first rough sawn from the log, it is a true 2x4, but the drying process and planing of the board reduce it to the finished 1.5x3.5 size. The lumber is then sold as a "2x4" because the cost of the drying and machining are figured in ... it is also much easier to refer to a board as a "2x4", rather than a "1.5x3.5".
Acoustiblok ® is a unique 1.1 lb. psf U.L. Classified, high S.T.C. reinforced dense noise isolating material for reducing sound transmission. is approved by U.L. for walls, ceilings and floors (see U.L. classification. It is usually stapled to wood studs
Each layer of 16 oz Acoustiblok ® reduces sound transmission by as much as 30 db depending on the frequencies.
A typical 2 x 4 gypsumboard stud wall is usually 33 to 35 STC. Acoustiblok® installed in the 2 x 4 wall is lab certified at an amazing "STC of 52", better than 12" of poured concrete (STC 51).