Installation Guide
The following is a basic step-by-step guide for the installation of Westman Steel’s steel roofing and siding.
STEP 1: Material Checklist
It is necessary to make sure all pieces are on hand before starting. Please stage your material according to roofing, side walls, end walls, sliding door sheets, trims and fasteners, and put them in a convenient location nearest to their application point. Make sure to use the correct length of sheet in the correct area and be careful to stage, or secure, sheets prior to installation from the elements, and wind, at all times. Please see storage recommendations attached. Depending on your application, some trims need to be installed before cladding, so to avoid delays please make ensure you have what you need.STEP 2: Install Roof Trim, Flashing and Westman Steel Underlayment
The examples of trims and fashings used in this guide are only representative of the products available, and may not be recommended in certain applications. Please call us for advice, or direction, as needed. While the use of trims/fashings are needed to ensure a weathertight building, some trims are optional and can be used to enhance appearance. The following installation instructions refer to fashings and trims that are either, in- stalled before the cladding (Before applied), or installed after the cladding (After applied). Determine which type you have purchased and follow the appropriate installation procedure. (a) Gable Trim (Before applied): To install gable trim, fit the pieces in place, fastening through (at 36'' spacing maximum) both top and bottom nail- ing fanges. If this type of trim is used, it is important to properly seal (sealer tape is commonly used) and fasten the cladding sheet along the gable to prevent water from migrating under the sheet and into the building. (b) Eave Trim (Before applied): Eave trim are installed before the roof sheets. There the Eave trim will cover wall sheeting, determine the wall panel depth (e.g. 3/4'') and fasten the top nailing fange of eave trim to allow a space for the wall panels plus a 1/8'' clearance. Use at least three fasteners per 10'6'' length of trim. (c) Corner and Ridge Boxes (if required): Corner and ridge boxes are optional items and are installed after the eave and gable trims are in place. Follow the manufacturer’s directions. (d) Dormer and Valley Flashings: Where required, install the valley fashings as shown. It is important that the valley fashing be supported by sheathing or blocking along its entire length. Without this support the fashing will not lie fat and it will be impossible to make a weathertight seal between the roof sheet and the fashing. The size and shape of valley fashings differ from one roof to another. A low-pitch roof may require a 36'' wide valley fashing, whereas a higher-pitch roof may only require one 24'' wide. The roofing sheets should be cut at an angle to accommodate the pitch of the valley. A ''W'' valley is more effective in channeling water off the roof than a ''V'' type. Care needs to be taken to close off the cladding ribs to prevent water backing up under the sheet. Flashing where the dormer meets the main roof area can be done using Westman Steel Roof Shield, which is an EPDM dormer cap designed for this application (shown as an On-Site Flashing below). Installation details for this can be found at the back of this Installation Guide. The dormer ridge cap needs to be cut and fitted under the main roof sheets. (e) Membrane: When sheet steel roofing is installed over a sheathing material such as plywood, it is common practice in some regions, and some applications, to install a synthetic underlayment, or a peel and stick membrane over portions of the roof area. Please consult with your Westman Steel representative for recommendations.STEP 3: Roof Sheets
(a) The first thing is to check the roof squareness. At the corner where an eave and gable meet, measure eight feet along the eave purlin and mark. Then measure six feet up the gable edge from the eave and make another mark. Measure the distance between the two marks. If it is exactly ten feet, you have a square roof at that corner. Check all roof corners using this procedure.NOTE: The following instructions assume that the roof is square. If the roof is not square there are two correction methods that can be used depending upon the severity. If the deviation is not too signiicant, it can be corrected a little sheet by sheet taking advantage of the tolerances in the sheet side laps. For unsquared roofs, the sheet along the gable can be trimmed along its length to match. An After applied gable flashing is used to reduce the visual impact of the trimmed sheet.(b) Identify the proper seam lap and the proper screw placement to fasten the sheets to the building.
NOTE: When walking on a roof, avoid walking on the ribs. Step where the purlins are and follow the fasteners up or across.(c) To get the roof sheets up on the roof, put a board or ladder against the fascia board and slope to ground as far away from the building as possible. Using vise grips and a rope, pull sheets up the board and onto the roof. This method is not suited to long sheets.
NOTE: Extra care needs to be taken on windy days to prevent the sheet from buckling or getting out of hand. Work safely.(d) Start at the eave on the end of the building farthest away from the prevailing winds. Extend the sheet about 1'' over gable edge and 1'' to 2'' over the eave. (e) Overlap sheet ends by at least 6''. Sheet end overlaps should only be made at a purlin for support. Lay sheets one by one from eave to ridge before commencing second row (below). Do not fasten open side before starting next row. Except for large buildings, a single sheet will span from eave to ridge without requiring overlaps. (f) Check sheet alignment every four to five rows by chalking a line square to the eave. (g) Leave the required space at the ridge to accommodate ventilation requirements.