Perma-Tite Expansion Joint with 3-Axis Movement

The Perma-Tite Expansion Joint with 3-Axis Movement is a formed metal cover from Metal-Era's Perma-Tite family. It spans the gap at an expansion joint on a low-slope roof and moves in three directions: in and out (lateral), side to side (lineal) and up and down (vertical). Vertical motion for live loads is accommodated with no loss of thermal or seismic motion. The cover has no exposed fasteners, and no caulking is used on the cover itself.

Two versions are covered here. The roof-to-roof version joins two roof systems, each carried on its own wood curb. The roof-to-wall version joins a roof system to a terminating wall. A continuous cleat protects the joint from wind-driven rain, and the joint prevents condensation by insulating against internal building temperatures. Expansion joints like this one are part of the metal detailing used with low-slope roof systems.

Metal-Era also makes Perma-Tite expansion joints without the 3-axis feature: a Roof to Roof version and a Roof to Wall version. Together with the two 3-axis versions, these make up four expansion joint versions in the Perma-Tite line.

The two versions differ in what sits on each side of the joint and in how the movement is recorded on the print approval.

• Roof to roof: a fixed curb on one side and a free curb on the other, with a condensate seal and insulation in the gap between them. The cleat is fastened to the fixed curb and held to the free curb through retainer plates, so the free side moves. Wood curbs and cants are by others, and each curb is a minimum of 1 1/2 in. wide.
• Roof to wall: a wood curb on the roof side and a surface-mount continuous rail on the wall. The rail's bottom edge sits half the noted vertical movement below the top of the wood curb. The print approval limits each movement to a maximum of 6 in. in and out, 6 in. side to side and 6 in. up and down.

Total expected movement is entered on the print approval as three values: A for in and out, B for side to side and C for up and down. Face heights, rise and overall width are set by Metal-Era from those figures.

Covers are manufactured in these materials:

• 24-gauge galvanized steel
• 22-gauge galvanized steel
• .040-in. aluminum
• .050-in. aluminum
• .063-in. aluminum

Standard colors are coil-coated with Kynar 500 and include a 30-year finish warranty. For Perma-Tite Expansion Joint with 3-Axis Movement, custom post-coated Kynar 500 colors include a 10-year finish warranty, and a 20-year warranty is available on request. Anodized finishes carry a 5-year warranty. Coil anodized finishing has no finish warranty, and post-coat Class 1 batch anodizing can be raised to a 10-year warranty for an upcharge. All colors are also available in mill finish.

On Perma-Tite Expansion Joint with 3-Axis Movement, ten express colors are offered: Dark Bronze, Bone White, Cityscape, Almond, Medium Bronze, Sandstone, Sierra Tan, Slate Gray, Stone White and Clear Anodized. Express colors apply to 24-gauge, .040-in. and .050-in. covers only.

Covers are provided in 12-ft. lengths with pre-punched, slotted fastening holes that allow thermal movement of the materials and fix fastener placement and spacing. The system attaches to wood framing on new or existing roofs.

The roof-to-roof assembly includes these parts:

• A 20-gauge galvanized continuous cleat in 12-ft. lengths.
• A 16-gauge galvanized continuous Z cleat in 12-ft. lengths for the free curb.
• Galvanized continuous steel rails on the curb tops, nailed to the fixed curb at 24 in. on center with 1 1/4-in. galvanized ring shank roofing nails and fastened to the free curb at 18 in. on center with #10 x 1 1/2-in. stainless-steel screws.
• Retainer plates, with 12-14 x 1-in. TEK 3 screws and shouldered washers.
• 20-gauge galvanized double-spring anchor clips, 3 ft. on center, between 6 and 8 in. wide.
• A 12-in.-wide concealed splice plate at each joint, with factory-applied dual non-curing sealant strips.

The special articulating cleat allows four-way movement for expansion and contraction of the roof. Shouldered washers, Tapcon screws, galvanized ring shank roofing nails and stainless-steel screws are also provided. The roof-to-wall version uses a 24-gauge galvanized continuous curb rail on the curb, a 20-gauge galvanized surface-mount continuous rail on the wall, an 8-in.-wide splice plate and 1/4 x 1 3/4-in. Tapcon fasteners at 18 in. on center into the wall, with non-curing sealant by others at the top lip of the wall rail.

The concealed splice plate has a raised stop that prevents the plate from migrating under the fascia panels, which avoids the cover plates and lap joints used at seams on traditional systems.

Factory-fabricated accessories remove the need for field fabrication. Miters and accessories are made with a non-penetrating quicklock joint and factory-sealed watertight unless otherwise noted. Welded miters and accessories are available at a surcharge. Specially fabricated products are available for the needs of an individual project.

The quantities to be ordered are lineal feet in 12-ft. lengths, outside miters, inside miters, and right-hand and left-hand endcap inserts. On the roof-to-roof version, endcap handing is read facing the fixed curb. On the roof-to-wall version, it is read as seen from the roof.

The installation instructions for the roof-to-roof version run in eleven numbered steps:

1. Condensation Seal: the membrane condensate seal (by others) goes into the gap between the curbs to a depth at least equal to the width of the expansion joint. Membrane joints are lapped 6 in. and sealed, the ends are folded in and held to the wood curb with contact adhesive (by others), and the membrane is trimmed even with the outside edges of the curbs. Fiberglass batt insulation (by others) goes into the membrane pocket.
2. Continuous Rails: the galvanized steel rail is fastened on top of the fixed wood curb at 24 in. on center, and the galvanized Z rail on top of the free curb at 18 in. on center.
3. Miters: curbs are field cut at a 90° angle, then steps 1 and 2 are repeated.
4. Miters: the miter cleat is laid over the curbs with the fixed side flush with the fixed curb. The cleat overhangs the free side, which is the side with the square holes. Screws are not overdriven, so that they do not restrict movement.
5. Miters: the miter cover is pressed straight down until a snap lock occurs on both legs.
6. Endcaps: the continuous cleat is placed over the curbs and secured with stainless-steel fasteners and shouldered washers, washers extruded side down, in the vertical slots of the fixed curb. It is secured to the free curb with TEK 3 screws through the retainer plates.
7. Endcap Inserts: anchor clips are placed 3 ft. on center after the release paper is removed from the VHB architectural tape on their undersides. The endcap insert is placed in the 12-ft. cover section, pop riveted and sealed with non-curing sealant on the inside seams, then hooked on the free side of the cleat and rotated into place.
8. Continuous Cleat: placed and secured as in step 6.
9. Anchor Clips: placed between the square holes, then every 3 ft. on center.
10. Splice Plates: centered on the anchor clips at the splice joints, 12 ft. on center, after the release paper is removed from the sealant strips.
11. Expansion Joint Cover: the cover is hooked on the free side of the continuous cleat and rotated into place until the rear leg snaps. A 3/8-in. space is left at splice joints for thermal expansion. Covers are field cut with a fine tooth hacksaw or snips, and the protective film is removed immediately.

The roof-to-wall instructions start with the same steps as the roof-to-roof version. In Condensation Seal, the membrane is secured to the wall to a height of double the noted vertical movement above the curb. In Continuous Rails, the 24-gauge curb rail is nailed to the wood curb at 24 in. on center, and the 20-gauge surface-mount rail is fastened to the wall at 18 in. on center with its edges facing out. Outside Miters and Inside Miters follow, with the miter cleat laid so that its vertical flange is against the wall and secured through the square holes into the wood curb. Washers on the wall fasteners are placed extruded side down at about slot center.

A 20-year, 120 mph Perma-Tite Wind Warranty is available on orders to meet a project's specification. It provides a maximum of 20 years and 120 mph coverage for repair or replacement of any portion of the roof edge system that has failed due to a defect in Metal-Era supplied materials. The finish warranties described above are separate.