Older aluminium louvres often break at the hinge
I recently had to replace three sets of aluminium window louvres because the original 1960’s rivets in the hinge had finally broken. Initially, I thought of replacing the rivet by drilling out the old one, but the amount of force on the hinge would probably be too much for a standard rivet. It’s much easier to just buy replacement cooper louvres from one of the major hardware stores.
I used Trimline louvres from Ullrich Aluminium that I bought from Bunnings for about $30 a pair. They also offer another option called Blade Lok which secure the glass in the holders but these are more troublesome if replacing louvres, as they take up more width due to the plastic locking strip. For most old louvres, this will mean cutting an extra few mm off the glass to fit. If your windows are on the second story like mine are, you’re probably not too concerned about securing the glass permanently.
What ever brand you use, check the spacing for the glass to make sure the old panes will fit ok.
Tools for the job
- Hammer
- Screwdriver
- Power drill and drill bit
You may also need
- Primer undercoat
- Sandpaper
- Paint brush
- Paint for a top coat
- Wood clamp
Removing the old louvres
First, remove the glass. Trying to do anything else first is just asking for trouble! The old louvres will probably have a thin piece of aluminium bent over the end of the glass pane to hold it in place. You should be able to bend this back by hand or you can use a pair of pliers. This will allow the glass to slide out easily. Be wary of splinters from the old glass but I don’t suggest using gloves without non-slip grips as the whole pane is more likely to slip out of your hands.
Once you’re removed the glass, you’ll find the mullion (the upright bit that screws onto the window frame) is attached to the frame with screws. These may well be seized-up, so grab your screwdriver and placing it on the screw, give it a short, sharp tap wth your hammer. This should loosen the screw. If pieces of broken plastic tinkle to the floor from your screwdriver handle, go buy a better quality one!
After removing the screws, don’t assume that the mullion will come directly off the frame. It could well be stuck with paint and may also be set into a routered groove. In my case, the mullion had to be tapped outward. If you need to use a hammer to remove the mullions, use it lightly and watch for splitting in the timber frame around any groove. If this is a problem, a clamp could be used to prevent splitting.
Preparing the window frame
Depending on the type of louvres you’re replacing, preparation may include priming and painting the timber window frames to cover areas that were hidden by the old louvres but aren’t covered by the new ones.
The new mullions are unlikely to have exactly the same profile as the old ones, so there may be some exposed, unpainted timber. Before painting this, put the new mullions in place, check for fit and drill screw holes. When checking for fit, pay attention to the spacing when the glass holders are in the closed position. Too tight and the glass will break. Too loose and you’ll get drafts.
When you’re sure the fit is right, start preparing the frame. First, using a damp cloth, remove any grime or your paint won’t stick. The old mullions will likely have a paint edge that needs to be sanded down to avoid an unsightly, lumpy line. When you’ve smoothed that down, put on some primer undercoat. Once this is dry, you need a couple of top coats to match the old paint. Lightly sand with fine sandpaper between coats to get the best finish. It’s not a good idea to try and do this after fitting because the locking handle and hinge makes it difficult to paint.
Fitting the louvres
Like most DIY jobs, the preparation is the time-consuming part! Once the paint is dry, all you need to do is position the mullions and screw them to the frame using the pre-drilled holes from earlier. Then, all you need to do is slide the glass panes back in and check the fit is right when the louvres are closed.
If the glass is a tight fit, you can use the heel of your hand or the rubber handle of a hammer to gently tap the pane into place. Be sure to keep it straight so that it doesn’t jam.
This is where your preparation proves it’s worth. If you rushed and drilled the holes in the wrong place, it can be very difficult to shift the mullion slightly and re-drill. It may be easier to drill new holes through the mullion instead. Just remember to punch the aluminium to create a recess for the screw-head.
