Methodology Aluminum Windows
Aluminum sliding windows are widely used for windows in recent modern houses. These windows are attractive, light in weight, easy to fix and need less maintenance, if properly fabricated and fixed.
Aluminum windows with big spans can be made with two, three or four tracks depending upon opening of window and number of shutters required.
Aluminum windows are available with powder coated surface. Powder coating can be done in different colours.
Aluminum windows without powder coating are also extensively used.
Material: The aluminum sections are extruded by most of the manufacturers and available in three types namely light section, Medium sections and heavy sections. Based on the location, span and area of opening the appropriate section can be selected.
a) The light sections are normally used for internal windows having opening span of less than 600mm.
b) The medium sections are used for external windows and spans exceeding 600mm with the opening area up to 2.1 sq.m.
c) Heavy sections are normally used for opening above 2.1 sq.m.
Frame section: The frame of aluminum window works as a base for track section. It is fitted on the sill, wall opening and soffit or lintel i.e. all around the sliding window. The frame consists of rectangular aluminum section. They are manufactured in three different unit weights as light, medium and heavy. These are to be used depending on criteria given above in para 2.0. The dimensions and unit weight of sections are given in Annexure 1.
Track: The shutters move on the track section. It is fitted to the frame. The track sections are available in various types like 2-track, 3-track, 4-track etc. There are two types of track sections required for each window, one is bottom track section and another is top & side track section. The bottom track section has additional part i.e. runner, on which the roller / bearing runs.
Shutter Section: The shutter actually moves on the track. It has rollers at the bottom and shutter section hold the glass with gasket.
Shutter Top & bottom section: This section fits to shutter in top and bottom. The shutter having same section at top and bottom. At section ‘a’ and ‘l’ below.
Shutter interlock section: This section fits to shutter on side i.e. in vertical position where another shutter is going to be interlock. All the middle shutters have interlock section on both the sides. The side shutter has interlock section on opposite side of wall. At section ( i-i ) and ( n-n ) in the figure below.
Shutter handle section: This fits to first and last shutter on the wall side of first and last shutters. At section ( j-j ) and (d-d) in the figure below.
Gasket: The Gasket holds the glass in the shutter section. The Gasket is made of PVC or Rubber. The PVC gaskets are Al. Section for Track more durable.
Track wool: The Track Wool, Roller Bearing available in running length, fits in the track section. It is used to avoid metal to metal contact Al. Section for Frame between shutter and track. The track wool should be put in the section after cutting the sections in size and before fixing.
General arrangement: The arrangement of aluminum Sections and other accessories used in two track Sliding Windows are shown here:
Procedure for making Frame: Aluminum windows are generally fixed after the internal and external plastering is over when hold fasts are not being used to fix the frame to the masonry. However, when hold fasts are to be fixed, a recess in the masonry is to be created to receive the hold fast, then cast in P.C.C. and plaster has to be given over the recesses later on.
First of all, measurements of the opening should be taken.
For fixing the aluminum window, the opening must be exactly in right angles and the diagonals of the opening must be equal, otherwise there will be gap between windows and plastered surface of wall. Measurements of length and height must be taken at three or four locations for each window, to ensure the conformation for size of fabrication of window of proper size. The gaps are not allowed in view of future leakages. If gaps occur due to mistake in the plaster, that gap is to be filled with Silicon sealant. Care should be taken to erect the window in such a manner that horizontal and vertical members should be exactly in right angles.
Rectangular tube sections are used to make frame for sliding window. It is always advisable to provide frame to the sliding window. The frame provides stability to the window as well as proper fixing to the masonry. The sizes of tube sections for window frame are shown in the table below according to number of tracks for window.
Frame sections and cleats used for various track.
(Rectangular Tube Sec.) outer dimensions
63 x 38.10
38.10 x 38.10 x 60
101.60 x 25.4
19 x 19 x 96
127 x 25.40
19 x 19 x 122
The tube sections are to be cut in the proper size as shown in the figure. The vertical frame section should be in full height of opening, top & bottom sections of frame are short length and fit inside the side sections. The cutting of aluminum section can be done by hack-saw but it is always better to cut by cutting machine to obtain a perfect right angle and smooth finish.
The wooden batten of minimum 450mm long are to be put inside the vertical tube sections at the ends as shown in the figure. On these vertical sections cleats as well as hold fasts are to be fixed.
The channel section can be used for making frame and wooden batten is to be put inside the channel for full length. It is sturdier than the hollow tube sections. After cutting the track sections in size, put track wool in the frame sections in the groove.
Fix the cleat angles to the vertical sections of frame at both the ends. The gap is to be kept, equal to web thickness of the frame section, from the end of vertical section. The cleat angle sizes are mentioned in the table. The angle cleats are available in various thicknesses from 1.5mm to 3mm and sizes. The cleats are fitted with two full treaded and plated metal screws of 3mm dia and minimum 15mm long. Each angle cleat must have minimum two screws on each surface i.e. four screws to each cleat. The screw should be entered in the wooden batten.
Fixing tracks to frame: Bottom track is heavier than the other tracks because it has extra runner for roller bearing. The tracks to be cut as per the inside dimension of frame. The corners be cut at 45° as shown in figure using a miter box. The angle cleats to be fixed to the bottom track as shown in figure. The top track will also have angle cleat. The bottom track is to be fixed first i.e. before fixing side and top track to the frame. The screw size should be 6mm dia and 25mm long. Then fix the side tracks to bottom track cleats then fix to the frame. Lastly fix the top track.
Making Shutters: To calculate the shutter size takes the measurement of window opening. Deduct the frame section thickness twice (2A), and then deduct the clearance of center web (B) of track section twice from frame. For the frame is fixed to wall only with screws into wooden plugs in the masonry but it is always better to provide holdfast.
In case of external windows, showcases of commercial establishments, holdfasts must be provided. Two hold fasts are fixed to the verticals on either side screwed into the wooden batten, fixed inside the hollow tube.
If hold fasts are not provided, fix the frame to the wall opening with screws of dia 8mm and 75mm long. The wooden plug / ravel plugs is to be put in the drilled holes before screwing in the wall. The rectangular section frame is to be fixed to the all-around the opening of window with screw. The first screw on all members from their end should be on 100mm and then spacing of screw should not be more than 45cm on each member of frame.
After fixing cleat to the vertical sections of frame, the top & bottom sections to be put on the cleats of vertical section, the cleats go inside the top & bottom section. Then fix the Top & bottom sections to the cleat with screws.
The holdfast is to be provided on both the vertical members of the frame. In the commercial system the holdfasts are not provided and the frame is fixed to wall only with screws into wooden plugs in the masonry but it is always better to provide holdfast.
Fixing tracks to frame: Bottom track is heavier than the other tracks because it has extra runner for roller bearing.
The tracks to be cut as per the inside dimension of frame. The corners be cut at 45° as shown in figure using a miter box.
The angle cleats to be fixed to the bottom track as shown in figure. The top track will also have angle cleat.
The bottom track is to be fixed first i.e. before fixing side and top track to the frame. The screw size should be 6mm dia and 25mm long. Then fix the side tracks to bottom track cleats then fix to the frame. Lastly fix the top track.
To calculate the shutter size takes the measurement of window opening. Deduct the frame section thickness twice (2A), then deduct the clearance of center web (B) of track section twice from frame. For vertical measurement the runner height of bottom track section is to be deducted additionally i.e. `C’ as shown in figure. This should be physically verified by measurements also.
Shutter Size = opening — 2 ( A + B ) – C – 3 mm
Put the marking on shutter section according to the measurements of track sizes.
The side sections like interlock and handle section should be in full length. The top and bottom sections are fixed with a L-Butt Joint in between the side sections.
The bottom ends of side sections are to be cut in `U’ shape for creating space for accommodating runner track of bottom track section. This `U’ also facilitates fixing one of the two screws to bottom shutter section. Another hole is drilled just above `U’ for facilitating second screw matching the projected lugs with threads in the bottom section. The top end is drilled with two holes for fixing the screw to top sections matching with the position of lugs in the top member.
First take bottom section and fit two roller bearings to it on either ends with 25 to 50mm margin from the ends.
Put the gasket inside the shutter bottom section and then put glass into the gasket.
Put the gasket to all sides of the glass.
Put the side sections to the glass according to the position of the shutter. The end shutters have handle section to one side and interlock section to the other side. Put the top section on the glass.
Fix all the sections with metal screws of 3mm dia and 25mm long coated with anti-corrosion layer as shown in figure. The screws fit with self-threading in the lugs (3/4th circle) part of the extruded section.
Fixing shutters in the track: Remove the top track which is fitted in step 3. It is necessary to first fit and then removing of top track for perfect arrangement of tracks and shutters. Put the shutters in the bottom track and hold it inclined. Put top track on the inclined shutters. Push the assembly in the frame from top side. Fit the top track section to the frame with screw.
If the height of the shutter is excessive the height of shutter is to be halved a glazing bar is to be provided in between, then the section used for the top or bottom section of shutter is used as glazing bar. The figure shows the arrangement of fixing glass and other accessories.
· The sliding operation of shutters should be checked for its free movement.
· Tracks should be cleaned with the help of vacuum cleaner or air blower.
· The gaps formed in between walls and windows should be grouted with epoxy based rubberized compound or silicon sealant such as tough seal or polysulphide with the help of grouting gun.
· If required M.S. grill should be fitted from outside for safety purpose.
To fit Jali shutter in sliding window, the wire mesh / Jali is put in to the shutter section. Pull the mesh from all sides. Then push a `U’ channel in to the groove of shutter section and fix it with screw. The Aluminum section of medium weight and thickness should be used for external windows with the shutter size up to width 25mm and the span up to 610mm. For the span above 610mm heavy section should be used and shutter size should be 30mm or more.