Fixing Instructions for the Rafter Gasket System (50mm Wide Rafter)

Transcription

1 Fixing Instructions for the Rafter Gasket System (50mm Wide Rafter) Tools you will need to construct your Rafter Gasket System Roof:- Tape Measure Screwdriver Spirit Level Hacksaw Drill Hammer

2 System Description The Rafter Gasket System is designed for installing Multiwall polycarbonate glazing onto 50mm wide rafters. It consists of a 50mm wide Rafter Gasket, and a screw-down Aluminium Capping Bar, which clamps the Multiwall glazing firmly and securely in place. Design Detail Multiwall polycarbonate is normally used on a roof with a gentle slope, which will allow rainwater to drain into guttering. A minimum slope of 5 Degrees is recommended. Sheets of polycarbonate will expand and contract as temperatures change, and room should always be left to accommodate expansion when joining sheets on glazing bars (Fig.1) Sheet widths should be reduced by 10mm to allow for expansion. For example, if you are installing 10mm sheets and your glazing bars are 700mm apart (centre to centre), use a 690mm wide sheet. Sheet Thickness 10mm Glazing Bar Centres 700mm When measuring up for your roof sheets, remember your sheet should be 10mm shorter than your glazing bars to allow for the fitting of aluminium U profile end closures. It is not recommended glazing 16mm and 25mm thick Multiwall on 50mm wide rafters. Should thicker glazing be required you could fix a quadrant either side of the existing rafter (Fig.2) thereby bulking it up to 60mm and use the Rafter Gasket Glazing System for 60mm wide rafters.

3 Step 1: Measure and set out where the rafters, and if applicable purlins, are going to lie. Rafters should be at 50mm wide when installing this System. As per the table on the last page, 10mm sheets should be accommodated at centres no more than 700mm apart (Fig.3). Step 2: Nail the Rafter Gasket to the rafters through the central channel with galvanised nails (not supplied) placed 300mm apart. Step 3: If installing on a roof over a room with enclosed sides, fix the Aluminium Eaves Filler across the structure at the eaves end (Fig.4). This solves the problem of filling the gap between the underside of the sheet and the top of the support structure. Step 4: Cut the Capping Bar to the required lengths and drill the cap at regular intervals with holes no more than 300mm apart, ensuring the holes will line up uniformly with the holes on each of the other bars once on the roof. The drill holes should be of a size to accommodate a 10swg screw. You can now start to fix the roof sheets; starting at one side of the roof and working across, fixing and dressing down flashings as you go. Please note, the multiwall sheets are UV coated on one side only. The sheet has a protective film on both sides, but only one side is printed. This is the side that should face outwards towards the sun. Do not forget to remove the masking film on both sides of the sheet. The ridge end of the sheet is sealed with solid Aluminium tape and the gutter end with anti-dust breather tape. Step 5: Having already fitted the Rafter Gasket to the rafters, fix a Side Trim Profile over the Rafter Gasket to the side of the fascia or building (Fig.5)

4 Step 6: If butting the glazing bar up to a wall face simply upturn the Side Trim Profile, fix to the wall and flash over (Fig.6) Step 7: Place an adjoining sheet with the Aluminium U Profile already fitted at the ridge end into position of the Rafter Gasket remembering to leave 5mm at either side for expansion. Fix through the Capping Bar and through the Rafter Gasket by using 62mm x 10swg stainless steel wood screws. Ensure that the screws are not over tightened as this will undulate the Glazing Bar Cap, limit the expansion and compress the sheet (Fig.7). Finally press down the screw cover caps. Step 8: Repeat this procedure for the remaining panels and on the last panel, repeat Step 5 or 6 to finish off. Step 9: Push fit the Plastic End Plate onto the end of the Roof Bar (Fig.8) Step 10: Measure and accurately cut the Aluminium U Profile End Closure to the exact length and fix over the anti-dust breather tape at eaves end of the sheet between the end of the plates. A small bead of silicone sealant can be applied to the upper side of the sheet along the line where it meets the U profile. Smooth this out to give a neat finish (Fig.9). Only use silicone sealant that is compatible with polycarbonate. Step 11: Finally dress down the Butyl Flashing.

5 As our policy is one of continuous improvement, we reserve the right to change specifications without prior notice. All information, recommendations or advice, written or verbal, is given in good faith and to the best of our knowledge