Major roof mods coming to W Marion Elementary.

The roof at West Marion Elementary School is shot.

It shouldn't be. The building, which opened in the 1991-92 school year, is covered with 30-year architectural shingles. But those shingles are baked, according to the school system's maintenance director, Garvin Trinks.

His assessment of the roof was presented to the School Board at the November, 2009 meeting, in the buildings and grounds report of Associate Superintendent Mike Murray. The shingles are brittle and broken. And the fix is more complicated than a simple tear-off and re-shingle.

On Murray's and Trinks's recommendation, the board resolved to ask the state Department of Public Instruction to assign their engineers to design a solution for a roof that cannot be fixed. That design work is now complete and Murray said he hopes work can begin this spring.

The work will include an extensive demolition of the roof structure. Trinks said due to both the expense and the disruption the work will cause, the job will be done in several stages -- probably five -- and the first stage should take about 100 days to complete.

What kind of roof can't be re-shingled without a major reconstruction? The kind that has absolutely no ventilation, Trinks explained.

A shingled roof requires ventilation. In a conventional roof, circulating air enters via soffit vents, passes between the rafters, cooling the plywood deck and the shingles that rest on it, then exits via a continuous ridge vent or strategically placed turbine or fan vents.

The roof at West Marion has no soffit vents and no provision to add them as the roof is now configured. That might be overcome with some clever engineering but the underside of the roof is the problem.

Fire codes in effect in 1989, when the building's construction began, called for a roof that has steel truss rafters to be sealed by two layers of 5/8-inch drywall for the sake of fireproofing. While that might prevent the roof from collapsing due to excess heat in the event of f fire, it also prevents air circulating in the attic from cooling the shingles.

The result? Shingles get very hot indeed, eventually baking. They become brittle and lose elasticity. So when the roof expands and contracts with changes of temperature and humidity, the shingles are unable to flex along; they break.

The solution the board has approved involves tearing off the shingles and deck. Workers will then install vertical (soffit to peak) strips atop the rafters, to create a 1 ½-inch airspace. Ventilation will be provided at the soffit via a continuous vent in the flashing.

The new deck and shingles will then be installed and should stay much cooler under the sun.

Trinks and Murray were reluctant to discuss their estimated cost for the project, as they said it could skew contractors' bids if they knew what the school system was willing to pay. However, the board did openly discuss cost at their meeting in November, as reported in The McDowell News at that time..

At that time the first phase was projected to cost somewhere in the realm of $350,000 and the entire project, all phases completed, around $900,000.

Superintendent Ira Trollinger said there was enough money in the system to deal with it.

"We have adequate construction funds to cover this," he said. "It seems expensive, but we recommend you move forward with this."

Maintenance will also take advantage of the opportunity to rework the drainage system and eliminate the concealed downspouts, which are buried in the walls. These will be replace with more conventional downspouts.

The problem with buried downspouts, Trinks said, was that if they get blocked with leaves and debris, they can trap and hold water in the walls, leading to rot and the possibility of mold.

West Marion's building is of a design common to several schools in McDowell. Will this be a problem at other schools?

No, he answered. The problem is entirely due to the fire barrier on the underside of the rafters. The fire code that mandated that barrier was only in effect for a very short time. The other schools do not have that problem, and their roofs ventilate properly.

Associate Superintendent Mike Murray said he hopes to begin taking bids on the work in the next few weeks, and that work should begin right away.

Trinks said he was grateful for the assistance of Ken Lawson, and engineer from the DPI who spent many hours travelling, consulting and designing.

"They're very good about helping us," he said. "When we call them they usually get right on it."