How to use acrylic sheeting for window repairs in France

I know I am always going on about using authentic materials, and generally I stick to that policy, but sometimes I let modernity into my life.

In particular, I find that transparent acrylic sheeting has advantages over glass for some, but not all, applications in this old house.

I first used it to make a very high triangular window in my barn, where manoeuvring a heavy piece of glass with pointed corners several metres above the floor would have been dangerous and needlessly tricky.

Next, when my daughter plastered a door with family photos, I found acrylic sheeting to be the perfect way to keep them flat, secure and clean.

Acrylic has really come into its own for glazing irregular windows. We have an irregular window halfway up the stairs which is cross-shaped and not well insulated. I used acrylic to make a rudimentary form of secondary glazing.

In the outbuildings, meanwhile, acrylic can also come in handy. In the barn there were several windows without glass that were annoying because they let in the cold winter winds.

The panes must have broken decades ago, leaving rotting frames hanging on rusty hinges.

I could have made new windows for these openings but it was not worth the expense or bother for a storeroom.

Cutting it to size

I had some pieces of acrylic left over, which I cut to size and screwed into the existing frames. They let the light in and keep the cold air out. What more could you want?

Flat acrylic sheeting goes by a number of commercial names. I am used to calling it Perspex, but in France the most common trade name is Plexiglass. Whatever it is called, it comes in different thicknesses from 2.5 to 10mm, and in a variety of lurid colours. I stick to the plain, transparent stuff.

The thicker it is, of course, the more expensive and heavier it is, so you need to find the happy medium for the job in hand.

Fortunately, it comes in large sheets. I have just brought home a piece measuring 1mx1.80m for the window over the front door. Acrylic is light, relatively easy to cut and, in most locations, no one will notice the difference. You can also drill holes through it more easily than in glass.

The first step is to take accurate measurements. Acrylic is a little more versatile than glass but you still don’t want to do much adjusting to make it fit snugly. Better a millimetre or two too little than too much.

Then to the cutting. A laser cutter is supposedly the best tool for this but who has one of those? Thin acrylic sheet (up to 5mm in thickness) can be scored with a sharp knife (on both sides if necessary) and then snapped in the same way as you would glass. However, like glass, it takes a little care and confidence to do this right.

Alternative methods include using a hand saw, complemented by a coping saw for rounded corners (hard work but if you must, you must). You could also use a circular saw or table saw, but such beasts seem like overkill to me in this context.

I prefer using a jigsaw fitted with a fine-toothed metal-cutting blade.

Whichever method you adopt, give the job your full attention. Clamp the sheet firmly to a flat surface and take your time, otherwise the acrylic may crack.

Wear gloves and a mask. When you are done, check the cut edge and sand it very carefully if appearance is going to be an issue.

Carry it to the site where it will be installed, carefully peel back the protective film on both sides, check for scratches and dirt on the side which you won’t be able to clear, fix it with screws, glue or silicone, and stand back to admire your handiwork.