The Butler MR-24 Standing Seam Roof Difference A comparison between metal roof systems
Roof Systems Necessities Weathertight (don t leak!) Low maintenance
Weathertightness Roof clips, seams, panel alignment Panel-to-panel end lap Penetrations Ridge condition Mid-span expansion Additions Miscellaneous problems and solutions
Five Types of Roof Systems Non- Ballasted Single Ply EDPM Ballasted Single Ply Four-Ply Standing Seam Metal Roof
Roof clips, seams, & panel alignment
Butler unrestricted 2½ movement, self drilling special Butler Scrubolt-- much heavier than a screw. Standing Seam Roof Clips Manufacturer A restricted 2 movement,self drilling screws Manufacturer B restricted 1½ movement, self drilling screws
Butler Field formed 180 with a 4 stand field seamer; a true seam Panel Seam Profiles Manufacturer A Panel is machine crimped in the field 45 Manufacturer B Panel is machine crimped in the field 45
Panel Alignment Manufacturer A Crooked panel side-laps can cause the roof clips to bind and restrict the free movement of the roof. Butler Panel side-laps of MR-24 run straight because factory punched structurals ensure roof clip alignment.
Roof panel-to-panel end lap condition
Panel Lap Problem Conditions Manufacturer A Nine sheet metal fasteners at each panel lap means nine roof penetrations per panel lap. On an average 100,000 square foot building this works out to be 8,640 panel lap fasteners roof penetrations!
Panel Lap Problem Conditions Manufacturer A Sealant forced out between panels, and panel gaps at side joint shoulder. Also sheet metal fastener has backed out due to panel movement and forces exerted at the panel lap. Manufacturer B Fishmouthing of mid-panel rib at panel lap between fasteners. Weathertightness is totally dependent on sealant which may or may not be in place.
Butler Endlap Solution Butler The sealant, Panlastic, features.05 nylon cubes. The cubes ensure the sealant isn t tightened out of the seam.
Non-staggered vs. Staggered End-laps Manufacturer A An attempt has been made to seal after the fact to eliminate leaks at these end-laps. Manufacturer B Close-up demonstrates the difficulty getting a tight-seal. All panel joints have been treated with a weatherproofing after leaks developed.
Non-staggered vs. Staggered End-laps Butler End-laps are staggered 5 feet off center to avoid four thicknesses of metal in seam. Also, panel lap is made over roof secondary that fully supports panel lap.
Roof penetrations
Roof penetration problems Manufacturer A Ponding at the up-slope of the curb has caused rust to eat away the Galvalume protective coating on the curb and panels. Two more problems exist: insufficient space provided between the curb cricket and panel rib, and the curb is attached to panels with sheet metal screws. Both conditions could cause a major roof leak.
Roof penetration problems Manufacturer B Roof curb sheet metal screwed to adjacent roof panels. Curb has leaked and repair has been attempted with sealant and roof coating material. Basic problem of insufficient side-drainage area and ponding not solved so that roof curb will be a continuing leak source.
Roof penetration problems Manufacturer B 30 coverage of Manufacturer B s panel with structural rib in center provides insufficient panel flat to accommodate Dek-tite base and still provide clearance for drainage. Dek-tite base has acted as a dam causing water to pond up-slope of penetration.
Butler Roof Curbs Curb is shop-welded to MR-24 panel base. This is a seamed-in curb with MR-24 side lap condition. View of curb prior to installation is from up-slope end showing the shopwelded curb with cricket in place.
Butler Roof Curbs Seamed-in curb in place--- view from the down-slope side. Note end-lap strap in place, applying equal pressure across the panel to curb lap condition.
Butler Roof Curbs Supplementary structural support system for roof curb to prevent ponding above and below the curb. Support system is pre-assembled and put in place over the roof secondaries and insulation. Roof curb and standing seam roof then installed. Support system maintains roof curb at the same elevation as the adjacent panels. This is a very critical element in the installation of a roof curb.
Roof ridge condition
Roof Ridge Condition Manufacturer A Ridge condition is dependent on sheet metal screws and sealant to remain weathertight. As roof expands, panels push against the screws and the holes around the screws elongate. This movement causes the sealant to work out, causing leaks.
Roof Ridge Condition Manufacturer A Roof leaks at exposed fasteners in ridge condition have become so prevalent that a final solution of coating the entire panel to ridge connection with Top Coat has been tried. Unfortunately, this, too, has proven to be a temporary fix.
Roof Ridge Condition Manufacturer B This is a more complex ridge condition that does accommodate panel expansion and contraction. Ridge condition lap with exposed sheet metal screws has already leaked and a repair attempted by coating the lap condition. Also, notice the fit-up between void closure and ridge cap is very dependent on sealants.
Roof Ridge Condition Manufacturer A Poorly aligned ridge condition is a result of poor execution practices. Ridge condition is designed to be 90 from panels and is difficult to seal panels to ridge if not.
Roof Ridge Condition Manufacturer A Rubber ridge termination did not have the contraction capacity of the roof and split. Strong dependence on sheet metal screws and mastic to seal ridge cap termination.
Butler Ridge Condition Butler ridge assembly in place prior to the installation of the 26 gauge curved ridge cover. Note the plastic plugs, in place over the seams, filled with sealant. Note the tight fit of the panel flute closure and the panel flat. Also note the absence of exposed fasteners penetrating the roof.
Butler Ridge Condition Butler ridge condition with ridge cover in place. Note the only exposed fastener is the lock rivet that holds the ridge cover to the ridge cover retainer--and this fastener is totally outside the roof enclosure envelope. Also note the rubber boot used as the ridge end cap to accommodate movement in the ridge assembly in all directions. Ridge cover plates are lock-riveted together 10 on center.
Mid-span expansion condition
Maximum Clip Movement Maximum Clip Movement Maximum Panel Length Manufacturer A 2 210 Manufacturer B 1½ 160 Butler 2½ 260
Roof Step Problems Manufacturer A Roof step at mid-span of roof slope. Lower elevation panels move in relationship to upper panels. This movement tends to work exposed fasteners--resulting in a high potential for leaks. This is particularly true when light gauge (.024 ) material is involved. Note treated fabric membrane exposed to the elements and attached with sheet metal screws.
Roof Step Problems Manufacturer B Due to considerable leakage, roof step has been generously coated in an effort to eliminate water infiltration. Photo also shows that the reliance on sheet metal screws to secure the panel tightly to the underlying structural member is not adequate.
Butler Roof Step Solution Butler s stepless roof features a horizontal truss-joist to stiffen the two roof secondary bar joists at mid-span of the roof. The roof panels will be anchored at this point and allowed to move toward the ridge and eave.
Butler Stepless Roof MR-24 standing seam roof panels showing the attachment of the panels to the stabilization channel at the panel side-lap. While the stepless roof condition does require 8 lock rivets with neoprene washers through each panel, these fasteners anchor the roof panels at this point. Fasteners are located above the panel flats and the use of neoprene washers for sealing the fasteners minimizes the chance of a leak. The stepless roof is much more weathertight than a roof step.
Butler Stepless Roof 336-0 unimpeded run of MR-24 stand seam roof panels from ridge to eave without a roof step to allow water to infiltrate the building.
Miscellaneous roof problems and solutions
Roof Edge Seal (Gable Trim) Manufacturer A Gable trim seams into the roof panel yet is attached to the building with exposed sheet metal screws. Photo inset shows trim laps opening and only mastic is preventing leaks. Butler Gable trim is a multi-piece that has a slip-joint which allows the one piece seamed to the roof panel to move while the actual gable trim is permanently attached to the building frame.
Pipe Supports Untreated wood supporting a poorly painted black iron pipe. Rust staining on the roof below pipe and behind pipe support will eventually destroy the Galvalume coating and the roof panel. Butler Butler s seam reinforcing clip with aluminum angles and unistrut to be used as a pipe or conduit support on MR- 24 roofs.
Work by Other Contractors Before Repair After Repair
Work by Other Contractors Before Repair After Repair
Butler Sky-Web In 1992, after several years of testing and development, Butler Manufacturing and BUCON introduced Sky-Web as a fall protection and insulation support system. To date, Sky-Web has prevented more than 35 falls and resulting probable lawsuits. Insulation Support System Manufacturer B When insulation support is required, most manufacturers use a galvanized chicken wire to support the insulation.
Gutter Support System Manufacturer A Gutter support system consists of a strap connected to the high leg of the gutter and attached through the standing seam roof panels with exposed sheet metal screws penetrating the roof. (Also shown are repair caps over sheet metal screws where the panel has moved and elongated the screw holes.)
Gutter Support System Butler The Butler system consists of a spreader bar locked into the gutter--maintaining the full width of the gutter--and a gutter hanger strap attached to the top of the MR-24 panel seam with a clip. Note this gutter hanger strap does not require any sheet metal screws penetrating the roof membrane.
Rib Closure Plugs Manufacturer A Panel side-lap rib closure held in place and sealed with caulking. Eventually this caulking will dry out due to ultra-violet rays and weather, and this rib will leak. Butler Butler panel seam rib closure in place. Note screw protruding through eave member. This screw holds the rib closure in place. Sealant is used only to seal between the rib closure and the standing seam roof panel.
Packaging of Roof Panels Manufacturer B How roof panels are packaged for shipment can have an impact on the weathertightness of the roof. With this type of packaging, it is difficult to: a) get the panels to lay flat on the roof secondary, and b) maintain constant panel width coverage, and, therefore, good panel alignment.
Packaging of Roof Panels Butler MR-24 Packaging Professional packaging of MR-24 roof panels assures their arrival to the job site in good condition--no damage to sidelaps or end-laps and no misshapening of the basic panel profile.
Low Maintenance
MR-24 Monolithic Standing Seam Roof Full double lock-seam same as a soda can. Perfect alignment for tight closure. A complete system with all the parts. Factory Mutual Class 1 rating for fire, hail, leak-resistance and wind uplift. Wind uplift ratings to I-120.
MR-24 Monolithic Standing Seam Roof, cont. UL 90 wind uplift rating. Corps of Engineers approval. Meets ASTM E330 uplift requirements. High energy efficiency. Low maintenance costs.
MR-24 Nearly 2 billion square feet in place