Go About Replacing Old Windows With Aluminium Windows

Aluminium windows are becoming increasingly popular for their durability, weather resistance, and environmental benefits, as well as for the way they improve the appearance of the home. Replacing your old windows with new installations of this material is not difficult, provided adequate safety measures are taken, and provided you have at least a basic knowledge of building and carpentry. However, before you can install your new windows, you first have to remove your old ones, and if this is not done properly, your installation will not be a success. 

Removing Old Windows

For removing your old windows, you need a reciprocating saw, a hammer, a wrecking bar and a knife. This task can be quite dangerous -- you should have at least two people on the job, and always wear gloves and eye protection. If your old windows have wooden frames, the easiest way to remove them is to pull the trim away from the outside of the window, and then go inside the house to take the glass panes out from the inside. Using your wrecking bar, you can prise away the window stops. Window stops are the strips of moulding that keep the panes in place. If the moulding has been painted over a few times, you may have to run the knife down it to free it more easily. For a sash window, first loosen the window stop from one side of the lower pane, and you should then be able to slide the pane out, followed by the upper pane. 

Once you have removed the panes, you can start halfway up the side window frame and saw through it just enough to sever it -- make sure you avoid hitting the plaster or wall into which it is fitted. If you then pry it out with your wrecking bar, it should start to become loose -- if it seems stuck, look for any nails that may be holding it, and use your saw to cut them. If the old window frame is vinyl, you will probably have to remove part of your siding to expose the flange -- you then remove the nails from the flange, and the window should slide out.  Once the frames are out, check carefully all-round the aperture, or opening, for any nails or other debris -- it needs to be completely clean before you start to install your new window.

Assembling the Frames

You are now ready to install your new aluminium window. Obviously, if you are actually living in the house, you need to install the new windows on the same day as you remove the old ones, otherwise the house will be uninhabitable overnight. This may mean removing and installing one window at a time, rather than removing all the old ones before starting to install the new ones. Your new frames will probably have been delivered to you in separate units, and you will need to start by assembling them according to the manufacturer's instructions. In doing this, you need to be very careful to ensure that the coupling joints are equal. If you want your joints to allow for thermal expansion without distorting the frame, you need to place sealing material actually inside the joint, at the time of assembling the frame -- the external sealant you apply after installation will not be sufficient. The sealing material could consist of polyethylene or polyurethane foam, flexible polymer gaskets, or bedding mastic. 

Positioning

Once the frame is assembled, you can then carry out the preliminary positioning. You should try to set it as far back in the reveal as possible, to maximise weather resistance, and you should also make sure you leave the correct movement gap. Set the frame plumb (absolutely vertical) within the aperture, making sure that no section is twisted or distorted. The best way to avoid distortion is to use installation packers next to the fixing positions -- the packers prevent the frame being deflected during installation, and increase security around the fixing point. They also support the frame, to ensure it is absolutely plumb. If packers are not supplied with the windows, you can easily obtain them from DIY stores.

Fixing

For fixing the frame, there are two main methods -- you can use one or the other, or both. Which method you use depends on various factors, including whether or not there is a wall cavity and what sort of cavity it is; the need to minimise damage or disturbance to your interior decoration; and the way the reveal is designed. One method is through-frame fixing, in which the holes are drilled in the frame, and the screws are either hammered or screwed through the frame into the masonry. The other is lug fixing, which will be used when the reveal is on the outer wall or over the cavity, while the fixing is in the internal wall. The lug is inserted into the window on the outside and fixed internally, so it crosses the thermal bridge. The lug needs to be made from a non-corrosive material, and used in conjunction with one-way screws, which must penetrate a minimum of 50mm. The installation packers you are using will ensure the lugs do not come into contact with the substrate, which would cause the lugs to be distorted. Foam fixing must not be used as the only method of fixing the frame into the reveal, but it can be used alongside one of the other two methods.

Installing the Glass

The next step is glazing. Your windows may be delivered ready glazed, or supplied along with glass units and gaskets, to be installed separately. When installing the glass, it is extremely important to follow the manufacturer's instructions, and to examine all the units before you start, for any chips or other damage. For all types of glass installation you will need frame-to-glass gaskets, setting blocks, location blocks, and possibly beads, bead end caps and bead-to-glass gaskets -- some systems also need glazing tapes. First, ensure that the rebates (the angles in the surround in which the pane is placed) are dry and clean -- there must be absolutely no moisture or dirt, or the pane will not install. Apply the frame-to-glass gaskets to the glass, and place the setting blocks on the bottom edge -- these are the small blocks of solvent material placed between the frame and the glass edge. These and the location blocks, which are placed on the side edges, are extremely important, as it is vital that the glass should not come into direct contact with the frame, or with any other hard material. The blocks also prevent movement between the pane and the surround. If beading is used -- beads are the strips of metal attached to the surround to retain the glass -- you then apply the bead end caps, clip the beads into them, and fit the bead-to-glass gaskets.

Finishing Off

One of the final steps in installing your window is sealing around the perimeter. This is essential, to repel water, and to prevent leakage of air in the case of any movement of the window against the aperture. For aluminium frames, a suitable sealant is silicone caulk. You should apply it against a firm backing, to force it against the sides of the joint, but avoid allowing it to stick to the backing. The best way to do this is by using a closed-cell circular foam strip. If practicable, you should also insert or inject an insulating fill behind the external seal, right round the perimeter of the window. 

Finally, the finishing touch is the trim, which can also be the same material as the frame, but does not have to be. For instance, it can be vinyl or PVC, but it should still be colour matched. Remember that, with this type of window, you cannot nail the trim to the window casing -- it has to be nailed to the outside wall. If you use wide trim -- 10 cm or more -- you will find this easier. 

Keeping your Windows New

Once installed, aluminium windows are very low-maintenance, but they do require reasonable care to ensure they keep their smart appearance. Most windows will have some unfinished and exposed edges, and these edges need to be cleaned at least every three months. However, you must avoid power washing or using a garden hose on them, as this can cause the sealant to fail. You must also avoid using harsh chemical cleaners, which could well leave permanent marks on the frames and ruin their appearance, although this will not affect the service life of the frame. Applying a car wax to the frames will protect them from dirt and grime, and make them shine. Alternatively, you can use a detergent solution and rub it gently on the frames -- never scrub or scour. If you find dirt and grime accumulating in the sashes or other grooves, the best way to clean them is to use a vacuum cleaner, with a nozzle small enough to fit into the groove and suck the dirt out. After cleaning the frames, you will want to spray on a silicone lubricant to protect them from corrosion. With the right maintenance, you will be able to enjoy your new windows in pristine condition, for decades to come.