Sash Window Draught Sealing: Yes, it is possible!

Sash windows can be known for their distinctive rattle, but it is possible to draughtproof them without affecting the smooth operation of the window. The typical gaps around your standard old sash window can all add up to the equivalent of six square inches!

Homeowners can buy simple draught sealing kits from their local DIY shop or online or have the windows draught-proofed when they are subject to restoration or repair.

The Benefits of Draughtproofing

The main benefit of draught sealing sash windows is improved thermal regulation. It doesn’t matter how high you have the thermostat in the room, draughts will always ensure you are cold, and the only thing that will be high apart from the thermostat is your heating bills.

Dust and dirt will also invade your home without adequate draught sealing. Another key benefit is the reduction or even total elimination of noise which makes a massive difference to old properties located in the centre of towns or which are roadside in a village.

Draught sealing old windows is far cheaper than a brand-new timber replacement. Best of all, our repair and restoration services include draught sealing as standard and attract a reduced VAT rate of just 5% for residential properties.

Does DIY Draught Sealing really Work?

It can do if you are competent at DIY, but a lot depends on the state of the window. When the window halves or sashes slide up and down, they can tend to rip off any glued-on window seals. Often, the gap between the window and the frame is irregular, so sometimes several layers of sticky seals are applied, which can worsen the peeling problem.

There are literally hundreds of different types of weather strips, draught excluders and bead strips available in a wide variety of designs, materials and styles.

Compression strips are made from a foam-type substance or flexible plastic material. Then there are bristle strips like a brush which don’t impede the movement of the window but will block out draughts. You can install non-permanent seals during the winter when the windows remain firmly shut and then remove them again, ready for the warmer weather.

It is hard for a non-professional to get the quality of finish that a professional installer would be able to achieve, especially if you can’t or won’t remove the window from the frame. DIY draught sealing, even if it works, is almost always visible as well, which affects the look of the window.

Professional Draught Sealing

The most common professional choice for draught sealing old sash windows is a brush seal in a uPVC carrier. These are popularly used in Grade I and II listed buildings which usually present the trickiest insulation problems. The low friction brush allows the sash window to glide up and down, and these are virtually invisible when installed, which keeps homeowners and the listings officer happy.

Another option is parting beads. These vertical seals fit between the lower and upper sashes and create a channel for the panels to slide past one another. Some parting beads come with a quality brush or weatherpile. Plastic parting beads should be avoided as they cannot be painted, and the plastic will discolour and fade, so it stands out from the rest of the paintwork. Parting beads for timber sash windows should always be made of wood.

Which is Better, Brush Pile or Foam Strips?

Foam strips are more accessible for the homeowner to fit but don’t last as long. Foam has a memory, so it doesn’t tend to return to its original density. It also perishes much more quickly, so it needs frequent replacement.

Brush pile can be inserted into all the different edges of the sash window so the top of the sash, the lower rail on the bottom, the meeting rails, the parting bead and the staff bead. We use a router and straight flute cutter to create a neat groove to secure the pile carrier with a small amount of glue. The brush pile is then dropped into the channel. This method also means that brush pile which is worn or damaged can be easily replaced.

We include draught sealing as part of the service when we repair and restore sash windows. We also manufacture all our new timber windows with brush pile draught sealing as standard. It’s invisible and won’t impact the design aesthetic, and it offers excellent thermal regulation whilst allowing the window to run freely. Enjoy excellent heat retention, less dirt and dust and reduced noise. We partner modern techniques with traditional craftsmanship to offer the very best in 21st-century living, whatever the style and age of your property.

Contact us here to learn more about repair and restoration for your windows, plus our bespoke sash window design services.