02 Sep LVL’s or laminated veneered lumber is very popular but…
ProBuilder Repairs ~ LVL’s or laminated veneered lumber is very popular and regularly specified by designers of late. Laminated veneered lumber is basically plywood strips glued and compressed together to form an engineered beam.
It used to be readily available (until the current supply issues), is gun barrel straight and can come in very long lengths. This makes it perfect for internal works.
However it is increasingly being used externally for decks and similar structures. If not treated and specified correctly it can become troublesome.
To use laminated veneered lumber externally it will have a minimum treatment of H3. This protects it against fungus and periodic wetting. H4 level treatment is required if it will receive more frequent wetting.
The have seen many failures which are a result of poorly specified design. Failures also result from the builder ordering the wrong beam (there are a few variations and this is not a generic beam). Worst of all is when suppliers incorrectly order or decide to substitute with another because of lack of availability of the specified material.
There have been some spectacular failures of late with samples of the failed beams being sent to overseas laboratories to find out what went wrong and who was the blame.
While this has been happening, which is an extensive time consuming exercise, the clients homes are left in tatters.
The attached photo shows how these beams can quickly turn to mush.
What brought about this post? A recent project with the incorrectly specified treatment for a fully exposed deck!