Sunday, February 10, 2019

Construction - Standing Seam Steel Roof - Part I: Shopping, Ordering and Receiving

Two and a half years ago, I posted on two design options for steel roofing that we needed to consider, viz., standing seam with concealed fasteners and the exposed fastener type that is used for siding more often than for roofing.  The former is less likely to leak because the standing seam diverts runoff from the junction between panels and almost all of the fasteners are located and protected under the seam where leakage around them becomes moot.  The exposed fastener panels have two drawbacks.  All of the screws remain uncovered and are subject to leakage if the hex-head screws are not tightened precisely for a good seal of the elastomeric washers under their heads.  Also, the seams are relatively flat lap joints that do not divert water to the degree that standing seams do.

At the time of that posting, I was leaning towards the cheaper exposed fastener option in order to stay on budget.  Since then, reality has set in; the budget has become so distorted (grist for a future post after construction is completed) that, when it came time to order the roofing, the additional cost of the concealed fastener design was easy to justify.  Also, the roof pitches turned out to be lower than I imagined at the time of the posting to the extent that the exposed fastener design would have been too much of a gamble.

But First, Why a Steel Roof At All?
Because it is more sustainable.  It contains recycled steel initially and it can be recycled again at its end-life, unlike petroleum-based shingles that end up land-filled.  The life expectancy of a steel roof is several times that of even the most expensive asphalt shingles.  And the steel panels resist hail damage better than shingles and can be purchased in highly reflective colors to reduce solar gain for a cooler roof.  White panels, for example, are 100% reflective; the light gray that we are using is almost as reflective (upon request, Menards corporate provides information on the reflectivity of its steel roofing colors that may not be available at the store level).  The energy embodied in raw materials, manufacturing and transportation to the end-user must also be included in any assessment of sustainability.  Shingles and steel panels both require extractive sourcing but the former is a one-use product while the latter is recyclable.  A comparison of the energy embodied in their manufacture is beyond my pay grade but I suspect the recycled content of steel may tip the scales.  Energy embodied in transportation to the end-user is a case-by-case scenario.  Our steel panels from Menards came from a plant near Omaha, NE that is +/- 375 miles away which is well within the LEED standard of 500 miles maximum for the transfer of materials to the building site.  

Should a Steel Roof Be DIYed?
In my experience, the learning curve for steel roof installation is flatter the than for some other phases of home-building such as plumbing the waste system or cutting stair risers and certainly less challenging than drywalling cathedral ceilings.  Perhaps the most difficult task is cutting panels that cannot be pre-cut by the fdactory.  As I will describe in a subsequent post, even that is manageable.  Having said all of that, I must admit that, for someone my age, hanging out on roofs is a little more iffy now than it used to be. Otherwise, a steel roof is easily within the scope of a DIYer home-builder.

Placing the Order 
Crates of roofing haphazardly strewn about by Menards'
crude delivery protocol 
I compared the price, quality and color selection of several manufacturers of steel roofing and decided to buy ProSnap Steel Roofing from Menards.  Apparently, one of its subsidiaries fabricates steel cladding products which makes their purchase relatively hassle-free for consumers and DIYers.  Indeed, I found the latter to be true except for their delivery equipment that was so awkward and inefficient that the outsize containers were dropped haphazardly at the building site.  Thank goodness I had forks
The damage to the long crate at the rear in the picture
above by the time it was moved to the garage;
 fortunately only one panel was unusable
for my trackloader with which to gather them up and move them to storage in the newly-built garage.

All that is required for a quote and to place an order are reasonably accurate scaled drawings of the roof(s) and a color selection.  I found out the hard way that not all drawings are treated with the same degree of thoroughness by Menards.  When achitectual drawings are submitted in parallel with the scaled DIY drawings, the steel plant emails digital drawings to the customer for approval and a signature.  However, with only DIY drawings, there is no digital feedback from the factory -- the order is shipped without any further communication.  

The accuracy of the factory drawings is best documented by remeasuring the roof with the factory drawings in hand before signing off on them.  Special attention should be given to panel lengths for intersecting slopes on either side of a valley.  And there are a myriad components other than the panels themselves that must be vetted such as flashings of several types, roof edge protectors, vented and unvented ridge caps, and several different fasteners, moisture blockers and mastics. 

Our color selections for roofing and siding were based on reflectivity, i.e., the ability to reflect the sun's rays, in order to maximize the efficiency of wall and ceiling insulation in summer.  Accordingly, we chose highly reflective light gray for the roof and bright white for the siding instead of less reflective, but perhaps more interesting, darker colors.

Staging the Components
The first step in the installation process is to unpack the delivery crates and organize the contents so as to verify that all the components have been received in good condition and to get a leg up on finding them as needed during installation. The latter was particularly important in our situation because three roofs of different sizes were involved, one of which was a hip roof for which the panels varied in length.  Also, as a DIYer, it was important to familiarize myself with the ancillary components that were specified by the factory as add-ons after the order was placed.

In our case, there were two glitzes, one minor and one extremely major. 
The minor one was a panel having localized damage -- denting and abrasion of a small area --  that rendered it unusable but for which Menards readily issued credit.  The bigger problem stemmed from the fact that the measurement I gave Menards for the length of the panels for the garage roof was 10" too short due to a transposition.  The steel for the garage roof had been a last-minute add-on to the original order and, after reviewing the paperwork, I realized that I had not received a digital drawing of the garage roof from the manufacturing plant for dimension verification and a signature before the order was processed.  In the absence of architectural drawings, the cost of the mistake was entirely on me as far as Menards was concerned at a cost of about $1,000.  The reality message here is that a DIY home builder accumulates a lot of knowledge and skills, sometimes the hard way, that have limited or no future value, especially for someone my age.  But that doesn't diminish the joy of the onetime  journey.

The next post covers the installation of the roofing.

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