Using Horseshoe Packers

Packers provide load distribution behind fixings and important alignment support. They prevent frame distortion when screws are tightened against uneven walls, helping keep the panels aligned and operating smoothly.

Why horseshoe packers excel in DIY installations

• Secure screw alignment. The open U-shaped slot allows the packer to slide directly around the screw shank — it stays put and cannot drop out or slip down behind the frame during final tightening.
• Resist compression forces. Unlike wooden wedges that can split or flatten over time, composite shims maintain their structural thickness permanently under screw pressure.
• Allow progressive adjustments. Drive your fixing screws partway in, check your spirit level, slide the required thickness of packers into the gap, then finish tightening the screw smoothly.

How to position and use packers

Commercially available packers generally come in standard thicknesses like 1mm, 2mm, 3mm, 5mm and 10mm. Always position your packers directly behind the fixing holes. If you tighten a screw into an empty space without a packer behind it, the screw pressure will bow the shutter frame out of line, causing the panels to stick or bind.

You can combine multiple packers together to match the depth of a wall bow — but avoid excessive stacking. If a large gap exists behind the frame, consider whether a shaped timber infill strip or an alternative installation approach is more suitable for your space.

Common questions

Do I need packers?

Generally, yes. Most window reveals feature minor plaster variations, and using packers ensures you can tighten your frame fixings without twisting the shutter frame out of shape.

Can packers drop out later?

No. Because the horseshoe shape slots directly around the screw shank, the screw holds the packer permanently in place once tightened.