Replies to This Discussion

Permalink Reply by David W. Daniel on July 11, 2009 at 7:41am

I have seen LVL's n Maine as beams and girders. I knew this technology was out there and available, but to my knowledge it is not here yet. The concept is great for construction purposes, but when this stuff lights up it fails quickly.

Permalink Reply by Michael Bates on August 2, 2009 at 7:05pm

I'm a residential electrician in new Jersey, In many large (10,000 sq ft and larger ) Homes these LVL and "power Lams" are the norm, they give the strength to carry the slate roof and span large areas, so rooms can be larger, dimensional lumber seems to be used just to fill out partitions, and most structural work is done with engineered lumber. I Don't believe resi sprinklers is enough, i also belive all TJI's should have at least 1/2 inch sheetrock on them in basements. I'm seeing spray foam insulation creating 0 "breathabilty" in thesee structures, causing the inability of hot air and gases to escape on their own. Triple pane windows as well trap the heat and gas and are less likely to "self vent" in a timely manner. in a recent Firehouse article I read that temps in and around the 800-900 degree F area will produce rollover and possibly flashover, as opposed to the 1200-1500F degree temps in the past. these glues give off more unburnt products of combustion that at these lower temps will ignite.
In a recent training excercise we did a thermal burn. the temps at the cieling were 800 degrees, all we were burning was hay and pallet material. What is concerning is that at those temps in a house with a fire load heavy on the synthetics , we are oftly close to flashover conditions. Venting will help this, but we need to be ready coordinate this with our handlines. Even small depts. that don't have a "truck" need to train and use venting tactics