Innovation is at all times happening within the development trade. New methods to do issues, higher merchandise, and sooner, extra correct knowledge to construct our designs round. That is very true within the retrofit steel roof trade.
Retrofitting of an present constructing is turning into more and more extra technical than it was within the early 90s after I started doing retrofits. Uniform loading of the roof design is a factor of the previous. We now have nook zone, edge zone, and ridge zone wind load areas. We’ve unbalanced snow loading, larger floor snow, and wind velocity designs.
This isn’t information to anybody concerned in new or retrofit development. What’s altering the retrofit enterprise is the addition of photovoltaic panels put in on older steel roofs.
Because the nation turns into increasingly energy-conscious and the price of electrical energy continues to extend, including photovoltaics after retrofitting with a brand new roof makes good sense for the next causes:
- Metallic roofing is the one roofing materials that has a service life exceeding the lifetime of the photo voltaic panels.
- The price of the photo voltaic panels is commonly supplemented by native and federal tax credit.
- Many utility corporations will purchase the surplus electrical energy generated by the panels.
- The constructing proprietor has their utility invoice diminished.
- The panels will also be put in with specialised roof clamps that get rid of penetration and potential leaks within the new roof panels.
- The portion of the retrofitted roof that helps the photo voltaic panels might qualify for accelerated depreciation.
So, every thing is all good, proper? You already know it’s, apart from one small element, the load. New photo voltaic panels can add 2.72/m2 (6 lbs/sf) or extra. That could be a lot to ask the outdated steel constructing purlins, which had been by no means designed to assist that load quantity.
Now the query turns into how do you take care of this extra lifeless load? Prior to now, we might usually should go inside the present constructing and attempt to add extra purlins to deal with the load. It is a sluggish, tough, and costly course of whether it is over an workplace space, that means the one approach to accomplish that is to take away the outdated roof, add purlins, set up extra ones on the wanted spacing, after which reroof.
Thankfully for our trade, notched zee, retrofit sub-purlins have been confirmed so as to add extra capability to the present purlins. Relying on the present constructing’s development, load will increase of two.72-5.44 kg/m2 (6-12 lbs/sf) have been achieved.
A structural evaluation will should be accomplished as a result of not all buildings will get pleasure from this enhance, however most will. This makes retrofitting with the considered including photo voltaic panels now or sooner or later a no brainer. It may additionally make the price of the roof retrofit rather more inexpensive.
Ask your panel provider or retrofit framing provider about this function in your subsequent re-roofing challenge.
Dale Nelson is the president of Roof Hugger, LLC. Tampa, Fla. Based in 1991, Roof Hugger grew to become a division of the LSI Group, Logansport, Ind. in 2016. Roof Hugger is a nationally acknowledged producer of retrofit framing programs for present steel roofed buildings. Dale holds a Class-A Florida Contractors License and a Florida Actual Property Brokers License. He has been on the whole contracting since 1973.