Published on Thu, Sep 15, 2005 by ack Kintner

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Home Improvement

By Jack Kintner

“It’s getting busy,” said Mitch Knutson of Knutson Drywall in Ferndale, who employs anywhere from five to over 50 drywallers at a time in a currently frenzied Whatcom county construction scene. Knutson said it won’t end anytime soon. “This is going to go on for a while,” he said. “So if you have work you need done you’d better get on a schedule.”
Knutson was in the process of applying the drywall inside Don and Debbie Scherk’s new house in the 9700 block of Allan Street, off H Street on the crest of the ridge near Blaine’s east side. The daylight basement walls of Scherk’s house are made of styrofoam filled with concrete for an “R” value above 50, but above ground the house is wood frame, and he’s gone with a more normal but still innovative insulation product from Canada called rock wool, marketed under the name Roxul.

“It’s cleaner, it won’t burn and it doesn’t absorb water,” Scherk said, “unlike the pink stuff.” While costing more, it’s a better sound deadener between rooms and as 9-inch batts will give the Scherks an insulation factor of R-30 in their great room’s vaulted ceiling. The walls have 5-inch batts, and the Weathervane windows are all double-glazed. Perhaps best of all, like the Trex boards he’s using for his exterior decking, rock wool is a recycled product, in this case recycled mine tailings called slag.

The slag is combined with natural basalt, an igneous rock, melted at extremely high temperatures and then drawn and spun into tiny individual fibers that are then bound into a dense, non-directional material much like wool is made into felt, except that the basic material here is rock.

Because of that it’s water repellent, never absorbing water either from interior moisture or burst pipes. It’s completely non-combustible due to a melting point of well over 2,000 degrees (1,100 C), meaning that even in an extreme house fire it will not burn. “It just gets kind of black when you put a blowtorch to it,” said Scherk.

As rock it’s chemically inert, non-corrosive and completely resistant to rot, mildew, mold and bacterial growth, making it virtually hypo-allergenic. “If we were standing here with pick fiberglass insulation as we drywall,” Knutson said, “we’d see all these little floating nits in the sunlight and begin coughing. But not with this stuff.”

The installers left a space of a few inches, as called for in most codes, between the ceiling insulation and the inside of the roof, and the roof itself is completely ridge vented, meaning that air circulates freely outside the insulation but inside the roof surface keeping everything aired-out and drier. With rock wool’s higher resistance to absorbing moisture then the structure stays even drier.

Home Depot in Canada once had an exclusive marketing agreement with the material, Scherk said, but now it’s available in regular yards. While at the moment it’s slightly cheaper in Canada, prices are quite volatile with so much demand for material. The product is new to the U.S. market but has been manufactured in Canada for two years. Scherk said he first heard about it on a Canadian home improvement talk show called “Home Discovery” on CKNW hosted by Shell Busey.

The gypsum drywall that Scherk is having Knutson install is the same product that’s been used for some time, somewhat refined. He’s using half-inch in the main part of the house and 5/8-inch thick drywall in the garage’s exterior walls. The main room in Scherk’s house soars to a peak 20 feet above the floor but Knutson said that it simply means his workers will stand on scaffolding to nail up the custom cut pieces of drywall cut by others working on the floor.

He said it will take about three coats of mud to finish the walls, some of which are to be textured but most of which will be flat. Corners will be finished rounded off with a 3/4-inch radius bullnose.

The 2,200 square foot house is finished with what looks from the outside like wood siding, but Scherk says it’s really a concrete product called Hardie Plank. It comes pre-primed and takes paint well, he said. “It’s harder to cut and is heavy to put on, but it will last a long, long time. It won’t warp or cup, is completely water resistant and once painted will hold it much longer than wood,” Scherk said.

Scherk said that his design for the main floor of the house surprised him when it was first framed in, “and I’m glad I had a good framer,” he added. The soaring ceiling one sees when first walking into the front door gives what he called a “wow” factor as your eye is drawn up to the ceiling, peaking 20 feet above double French doors that lead out onto a front deck.

Knutson said that such high places inside don’t really make his work any harder, though. “Installing it is pretty much the same, whatever you happen to be standing on,” he said.