How The Nu-Lok Roofing System Works

1The Nu-lok™ fastening system starts with a conventional waterproof membrane installed over the plywood deck. As with any roof, the membrane must be fully waterproof and able to shed moisture off the eaves.

2Once the membrane is installed and inspected, a series of parallel counter battens are nailed perpendicular to the roof eave. Counter battens should be nailed through the plywood directly into the rafters. The spacing of the counter battens should not exceed 24-inch centers. Installing the system on counter battens elevates the Nu-lok system above the deck and allows natural ventilation. This also prevents water condensation from being trapped behind the horizontal battens.

3Galvalume battens are then laid horizontally across the counter battens and parallel to the eave. The horizontal battens are fastened with galvanized ring-shank nails through both the counter battens and plywood deck into rafters. The battens are installed at 12-inch spacing with care taken to insure exact spacing and parallel runs.

4With the battens nailed down and starting at any row on the roof, link channels are positioned and locked into the upward facing flange on the battens.

5The link channel eliminates the need for horizontal overlap between slates, as each link channel spans the horizontal gap between the two slates it supports, catching water seepage and conducting it onto the next course of slate below. In essence, each link channel contains a 3/4” wide, 5/32” deep miniature gutter.

6Natural or ceramic slates are then placed on the link channels and centered. The front edge of each slate is slotted into the 316 stainless-steel retaining clip fitted into each link channel. When correctly positioned, the two front corners of each slate are suspended by the clip, and the side edges of each slate are centered over the internal gutter in the link channel.

7The next slate is then butted against the one next to it, and secured at the corner by a stainless steel clip. The process is repeated to complete a horizontal course. Another course is then started, working up the roof, by locking the next row of link channels into place. Each row of link channels also secures the top of the slates in the row below. No nails are used.

The stainless steel clip serves as the fastener in the Nu-lok suspension system. The clips are black oxidized, and while visible up close, their non-reflective black color and low-profile design make them nearly undetectable from the ground. Clips are inserted into the link channels at the job site before loading on the roof.

Roof valleys

1As with any hard roofing product, attention to valley flashing details is extremely important. However, unlike most roofing systems, the Nu-lok suspension system uses four layers of valley protection. The first layer of valley flashing and the waterproof membrane are both installed prior to installing battens. A single layer of 26-gauge galvanized sheet metal is bent and fitted into the valley. Once the sheet metal is seated, a layer of waterproof membrane is rolled over top. The valley is now prepared and the Nu-lok battens can be installed.

With a closed valley, the battens should extend across the roof and into the valleys. The 12-inch horizontal spacing between parallel rows will remain unchanged. However, battens will not be tightly jointed within the valley. Instead leave a small gap between each set of battens.

2Upon completion of the batten installation, the valley soakers can be prepared. The soakers serve as the third layer of protection. These 9.25-inch wide by 20- to 24-inch long strips are folded on site to approximate the valley angle. They are then fitted into the valley and secured on the batten.

3With valley soakers installed, the valley is ready for slate. Both natural and Nu-lok ceramic slate can easily be cut to fit into the valley. Field measurements are taken and each side of the valley is closed with a custom-cut slate. With closed valleys, care must be taken to insure a clean accurate fit of the valley slates. With open valleys, use one long top-to-bottom flashing in the valley, leaving the horizontal battens cut short to allow installation of the flashing.

4With no unsightly valley flashings exposed, the closed finished valley is impervious to leaks. Unlike a traditional slate installation, Nu-lok allows for valleys to be completed prior to installation of field slate. This gives a large unimpeded work space on the roof. Materials can be easily loaded to the roof, cut and installed without damaging or replacing existing courses of slates.

Nu-lok roofs are safer and easier to install

Another benefit of Nu-lok™ is that a steeper roof can be stacked out for installation without scaffolding or roof brackets. Battens allow the installer to walk up a steeper roof and also allow stacking small piles of slate behind the battens. This makes installation much faster as materials are laid out in front of the installer as he works his way up the roof.

Every Nu-lok roof is fully walkable. Nu-lok™ supports each slate more evenly than a traditional nailed-in-place installation, allowing tradesmen to walk on the roof without risk of slate breakage. This makes finishing and trim work easy to do.