Basket (0) Checkout
0800 612 7859 Lines open today 8:30am - 5pm

Frequently Asked Questions

We have compiled a list of frequently asked questions that we receive from our customers. If you need any further help or advice, please do not hesitate to contact us and we'll be happy to help.

Is Gapseal visible when it is fitted and what colour is it manufactured in?

Gapseal is magnolia coloured and is invisible once fitted in white or cream coloured windows.

When is it best to insert Gapseal? Does inserting in the gap between window and frame cause any damage?

You can fit the seal at any time. As long as no excessive force is used, no damage occurs, and a plastic applicator is supplied to push the seal in without scratching the window

What is the delivery time for Gapseal?

If orders are placed before 2pm, we usually dispatch the same day. We use Royal Mail (2-3 working days) for orders of 1-2 packs of Gapseal. Orders of 3 packs and more are dispatched on a next working day service (Monday to Friday) by courier.

How do I know how much Gapseal will be needed?

Gapseal is supplied in 10m length. Just measure the length of the window gaps to work out the number of Gapseal packs needed. Please keep in mind that the product stretches when applied in thin gaps and can then cover a longer gap!

Can I not fill my sash window and other gaps with pretty much anything?

You can fill window gaps with the readily available window/door seals or you can use scrunched up newspaper which will work for a period of time. However, the newspaper will get mouldy and fall out after a while and the traditional seals can not be easily fitted in sash windows and do not work if the gap width varies. Gapseal will last and can cover a wide range of gaps (2-7mm).

Can I open my window when Gapseal is fitted?

Yes, however, Gapseal falls out when the window is opened but it is simply refitted when the window is closed again and can be re-used many times.

Is there a helpline for Gapseal, and when can I call?

We have a dedicated free phone number dedicated to sales and support, 0800 612 7859 open Monday to Friday (08:00 - 17:30) and Saturdays (10:00 - 14:00).

Can I paint or treat the windows after I have fitted Gapseal?

If the windows do not need to be opened again in the future you can leave Gapseal in the gaps while painting the window. If the window is required to open then we recommend that you remove the seals and refit them again after painting.

Does Gapseal absorb moisture?

Gapseal does not absorb moisture.

Can Gapseal be used around doors?

No, as Gapseal is not glued on it would fall off the door frame. In uncompressed state it would also be too thick for a normal door. When fitting to windows Gapseal is stretched to the tickness required and will then expand to the correct thickness which would not be possible in the case of doors

I have very wide window gaps. Is Gapseal suitable?

As long as the gap is less than 7mm, Gapseal can be used

What is the optimum depth for Gapseal to be installed?

Try to stay 2-3 mm below the surface to maintain the natural look of the window.

Can I use Gapseal on unpainted wooden windows?

Yes, the finish of the window does not affect either the installation or performance of Gapseal.

Our Customers Love Gapseal

4.5 / 5 Stars

Read reviews from 162 customers who've installed Gapseal to eliminate draughty windows and make their homes warmer.

Buy Gapseal Now

Gapseal 10m Pack

Suitable for 2 - 7mm gaps
More than 20 in stock Expected dispatch: 27th Aug

£13.99 inc VAT

£11.66 ex VAT

Additional Application Tool

Do I need another applicator?
More than 20 in stock Expected dispatch: 27th Aug

£2.29 inc VAT

£1.91 ex VAT

Sub Total:

£0.00 inc VAT

£0.00 ex VAT

FREE Economy Delivery

All UK orders are shipped FREE of charge and delivered in 2-3 working days by Hermes as standard.

Please Note: Deliveries to islands and remote locations can take an additional 1-2 days to be delivered.

Next Working Day Delivery

Orders can be upgraded to next working day delivery for
£4.50 inc VAT and will be delivered by DHL.

Next Working Day Delivery

Orders can be upgraded to next working day delivery for
£4.50 inc VAT and will be delivered by Hermes.

International Delivery

We offer an international shipping service for customers looking to buy Gapseal from outside of the UK.

If you are interested in an international delivery please contact our international sales team for a shipping quote.

Image Gallery

An excellent collection of images showing sash window gaps that have been sealed using Gapseal sash window gap filler.

See Full Image Gallery



This site uses cookies to improve your experience and for essential functioning of the site. By continuing to use our site you agree to the use of cookies.

Change your cookie settings at any time by clicking on the button at the bottom of each page. Read more about the cookies we use in our Privacy Policy.

By continuing to browse this site you agree to the use of cookies. Read our privacy policy to learn more.