25mm Square Window Sill

Availability: In stock

Your Square Window Sills will be dispatched between and (+1 day if choosing our waxed finish option) with free next day delivery.

*NEW* 'Priority' option now available during checkout for faster dispatch.

High quality square-edge window sills machined using only the finest Oak and delivered to your door directly from our UK workshop.

  • Seasoned oak timber to ensure you're buying the best
  • We can trim your sills to a more precise width/length if you need
  • We'll sand your sill after machining to ensure perfection
  • Order lengths in increments of 0.3m to save on costly wood waste
including VAT & free delivery
Shopify secure badge

Technical Specs

Read all about the specifications of our square edge window boards, including available finishes, sizes and optional extras.

Window Board

0.6-2.4 metres (2-8 feet)
200-300mm, wider on request
Solid Oak
Unfinished, sanded

Optional Extras

Cut to Size
Our oak window boards can be trimmed to your exact dimensions free of charge
Wax Finish
Choose one of our wax finishes and we'll provide your window board 'finished' to your specification

Oak Species

American White Oak (Quercus Alba)

Key Features

We pride ourselves on machining and supplying some of the best oak window sills that money can buy. Here are a few of the features that make your buying decision a whole lot easier.

Solid kiln dried oak

No veneers or MDF here! We only use high quality kiln dried solid oak for our window boards, offering a beautiful finish and durable sill.

Trim to size option

If you want to fit your oak window board as soon as it arrives, we can trim to the exact length and width that you tell us to when ordering.

All of the hard work done

In addition to optionally trimming your window boards to size, we'll machine and sand every piece to ensure an excellent overall finish.

No costly wood waste

Using our ordering options, you're able to choose a window board that most suits your size requirements, from 0.3m length and 25mm width increments.


We understand you might have a few questions you'd like answering before ordering. Here we list a few of the most common one's, though you're welcome to contact us should you have something else to ask.

Do these sills need sanding?

We do that for you. After machining, we sand all of our window boards to ensure a perfect finish.

Would you trim the sills to size for me?

Yes. Simply select the next size option up to what you need and in the 'Trimmed to size' section of the ordering form add your dimensions.

What does delivery cost?

All of the prices you see on our website include free delivery. We like to make it easy so there aren't any unexpected costs sprung on you during checkout.

Customer Reviews

All of our reviews are by 100% verified customers.

Based on 4 reviews Write a review

Customer Reviews

Based on 41 reviews
Jimmy James (Hassocks)
Really lovely piece of oak, expertly packaged

I Bough a piece of 25mm American oak to make a windowsill. It arrived beautifully packaged in lots of cardboard.
It arrived perfectly planed flat and I sealed it straight away with osmo oil on all sides, top and bottom before fitting in into the window. Sadly 2 days later it has slightly cupped and is about 2mm lower in the centre than the sides. Which means I’ve had to lift it and reset it. It keeps moving slightly so am just waiting for it to stop before fitting again. It did appear well seasoned on arrival so maybe I just needed to leave it a bit longer before fitting it. It’s in a dining room so low humidity and temperature variations too so I didn’t think this would be a problem. Overall I am very pleased with the piece of oak and the service from essential woodwork, just that the final job wasn’t 100% unfortunately.

Thanks for the review Jimmy, and for providing photos of you using the Oak - it's great to see the process from start to finish. One of the biggest hurdles for us is making sure couriers don't put all of the work to waste with damages, so we try to ensure the packaging is as protective as it can be.

As I'm sure you understand, with Oak being a natural product, 'movement' in timber is always possible and one that we can't avoid or predict due to several contributing factors. We make sure that products are flat once they're dispatched but unfortunately can't control what then happens when customers receive the item. What we always suggest is using a fixing that is strong enough to hold the board, which in our experience is expanding foam. Screws and glues aren't usually great at doing this, and when movement in timber does occur it's usually because of the fixing not being strong enough to hold the Oak from moving.

I'm glad that you're pleased with the Oak overall and hope your board has now settled. If you need any help or ever need anything else you know where we are.

Samuel Devine (Swansea)

It was cut to the exact measurement, matches my doors perfectly (American oak). Great service too! Buying two more now. Thanks guys, I have a feeling I’ll be back a third time when it’s time to add shelves!

Thanks for the great review Samuel! Good to know that you trusted us with further orders, and if you should ever need any shelving doing you know where we are!

Richard LEIGHTON (Royston)
Oak window boards

Great service well packaged quality boards. Will be back for more.

The window board looks perfect now fitted Richard, thanks for sharing your photo. I look forward to hopefully hearing from you again soon if you ever need anything else.

Nick Gibson
Oak cill

I ordered two of these (due to not measuring twice-d’oh!) and both were of excellent quality, and arrived extremely well packaged and un-damaged. 100% recommended, will use again.

Always a pain to have to order twice for the same job, but at least you're happy with the Oak and hopefully you managed to make use of the other piece elsewhere!

Thanks for uploading a photo Nick, always appreciated. Love the wall colour too :)

Robert Phillips (Ottery St Mary)
Suspect delivery

No problem whatsoever with product. Exactly what I ordered and - thankfully - extremely well packed. However delivery dreadful. Delivery assured Tuesday, then Wednesday, then Thursday. I suggest you change you carrier.

Thanks for the feedback Robert. I’m glad that you’re pleased with the window board, and sorry you had a bit of difficulty with the delivery. To be totally honest, taking a look at your order it appears that you were one of the first customers that we dispatched too using a new courier, however we also had a couple of teething problems when we started using them.

There were a couple of days whereby the courier had collection issues whilst they setup our account, which may have explained a day or two delay, but it appears that you may have had another unrelated delay (which can occur from time to time with all couriers). I’m hoping that this is a one-off and apologise for the inconvenience. Should you ever need anything else let me know and I would hope that you wouldn’t experience the same courier issue.

k bhurji (London)
Oak window board

Looks fantastic very pleased with my window board, will use again 😀

Thank you! Hopefully see you return sometime soon :)

You Might Also Like