Double glazing, sliding windows and materials – your noise questions answered

Over the years our customers have asked us a number of questions surrounding how to reduce the noise coming into their homes. Three questions keep popping up and we have sought to answer them below.

The first surrounds double glazing, and whether this affects noise.
The second surrounds materials and how material type and quality reduce noise.
Lastly, many people ask us about the difference between sliding doors and normal casement windows.

If I just double-glaze my windows, will that keep the noise out?

It is very tempting to believe that a double-glazed window alone will keep the noise out. Studies have shown that in colder climates double glazed windows have an insulating effect thanks to the enclosed air layer and help keep homes warmer, so there is a perception that they can keep noise out too.

However, when it comes to noise this is not the case, we often speak to customers in Singapore who double glazed their windows – at great cost – only to realise that it made no difference to the noise levels in their home. A significant amount of noise doesn’t come through the glass, but via the gaps between the glass and the window panel. In fact, we have seen single-glazed windows that are expertly fitted outperform a double-glazed window fitted in a typical manner.

So, a window that is precision fitted by a qualified workman that ensures a weathertight seal between the panel and the frame will keep much more noise out.

We recommend 45DS window system

Our 45DS system is a fixed, casement, and turn-tilt window system capable of 34mm glazing capacity which provides the capability to match the best glazing options for best acoustic performance up to STC 42, which has been tested and certified by third parties in international tests.

It also has industry leading unique technical features which are currently exclusive to AluK in Singapore such as ‘Pre-Machined Friction Stay Mounting Plates’ for perfect alignment under any circumstance, as well as ‘Hexagonal Shaft Locking Cams’ to ensure locking tightness that will last decades without any performance drop.

I hear that uPVC performs better than Aluminium for noise insulation, can’t I just change the material?

Unfortunately, the materials used in the windows have little bearing on the amount of noise the windows allow in. While some materials are certainly better insulators than others, the reality is the actual material itself contributes very little to the acoustic performance of the window. The glass should have a good acoustic rating, but ultimately the fitting between the window and the panel should be weathertight.

Noise Plaster uses rubber to help reduce the acoustic ‘leakage’ of our windows. This is very similar to modern submarines where silence is the number one priority. Many of the fittings within a submarine are attached to walls and ceilings with rubber, which reduces vibrations and deadens the sound meaning from within the boat. We use the same principle with our windows whereby rubber fittings between window and panel reduce sounds and vibrations.

Black rubber fittings connect internal appliances to the hull and block noise. Image Source : Carl Howard

uPVC may well perform better than aluminium for noise insulation. However, a well fitted, weathertight aluminium window will still perform to the same acoustic level as the best-fitted uPVC windows.

Lastly, in Singapore there are a number of other reasons not to go with uPVC. uPVC is less fire resistant and SCDF Fire Code 2019 had updated regulations to require stricter control over installation of uPVC Windows. Furthermore, SCDF requires all uPVC windows to be tested and listed under the Product Listing Scheme and subjected to an annual surveillance test.

We recommend: 45V window system

The 45V system offers a very unique design option, in which it is a slide-fold system which allows for maximum openable dimensions while offering a completely soundproof system when closed.

By drawing on over 50 years of experience in aluminium windows, AluK has designed the 45V system with dual overlap gaskets, interlock gaskets as well as multipoint intermediate locking devices to ensure the complete weathertight integrity of the slide-fold system when fully closed.

Sliding windows are much noisier than other types, so should I stick to casement windows?

Yes, and no… sliding windows are common in Singapore especially in flats that have balconies, and they can be very convenient too. However, the sliding windows in many flats and poorly fitted leaving considerable gaps between the windows themselves and the fitting.

These gaps allow noise to filter in and given the size of many sliding doors – they are typically much larger than casement windows – this creates the impression that sliding doors let in more noise than casement windows. We have seen some cases where it is just as noisy when the sliding windows are closed as when they are open!

Thankfully, advances in technology have allowed us to develop sliding windows that have much greater levels of noise reduction as well as thermal insulation properties. These systems have very elaborate profile designs and gasket systems that address all possible avenues of air leakage through a sliding system. This, combined with a skilled workman who can fit the window properly, means that sliding windows can be as silent as casement windows.

We recommend: SC95 sliding window system

The SC95 is an inline sliding system which integrates custom designed brush gaskets with polymer fins to maximize soundproofing. In addition to that it has double interlock gaskets, as well as inter-panel gasket blocks to ensure complete soundproofing performance. Its reinforced mullion design also ensures that the soundproofing performance is not compromised due to profile deflection even at large panel sizes.

The SC95 soundproof sliding system also has industry leading unique technical features such as ‘Gasketted Endcaps’ which, by sealing the gap between the track and sash, shows attention to detail in the design to completely seal off all gaps in the soundproof window. We also have ‘Internal Driving Handles’ which make a soundproof sliding door as easy to operate as a normal sliding door, despite the increase in weight and friction due to its soundproof construction.

For more queries, get in touch with us.