Need to cut a doorway or opening through a thick wall in a tight space?
If you need a new doorway, window, hatch or service opening cut through a thick concrete or block wall — and there’s not much room to work in — ring sawing is usually the right tool for the job. Diamond Drilling UK provides ring sawing across London and the South East, and it’s one of the techniques we’re asked for most often on refurbishment and fit-out projects.
A ring saw uses a circular blade driven from the outside rim rather than a central spindle. Because there’s no spindle in the way, the blade can plunge straight into a wall and cut to nearly twice the depth of an ordinary saw of the same size. It can also cut tight into corners and finish the edges of an opening cleanly without overcuts — something a wall saw can’t do.
What ring sawing is typically used for
New doorways through thick concrete or block walls
This is the bread and butter of ring sawing. A typical job is a 2.1m by 900mm doorway through a 200-300mm reinforced concrete or solid block wall — the kind of opening you can’t cut neatly with a circular saw because the blade can’t reach the depth or finish the corners. We cut the opening, mark out the corners precisely, and leave a clean rectangular hole ready for a lintel and frame.
Serving hatches and openings in commercial fit-outs
Restaurants, cafes, shops and offices being refitted often need openings cut through existing structural walls for serving hatches, pass-throughs or new internal windows. Ring sawing produces a clean rectangular opening with crisp corners, which makes the joinery and finishing far simpler.
Openings for steel beams (RSJ insertions)
When structural engineers spec a new steel beam to support a knock-through, we cut the slot for the beam to sit in using a ring saw. The clean depth and accurate corner finish mean the beam beds in straight away without packing or making good.
Window openings in basements and conversions
Basement conversions often involve cutting window or light-well openings through retaining walls that are 250mm or thicker. Ring sawing handles the depth and leaves a clean finished edge.
Openings for stairs, lifts and risers
Where a new staircase, lift shaft or service riser needs to be cut through an existing slab or wall and access is restricted, a ring saw can plunge straight in and finish the cut precisely — no oversized starter holes, no overcut into the surrounding structure.
Why ring sawing rather than another method?
The main reason customers ask for ring sawing is corners. A normal circular saw or wall saw will overcut into the surrounding wall at each corner of an opening because the centre of the blade is offset from the cutting edge. That’s a problem if you’re cutting a precise doorway in a finished wall, or working next to a structural element that mustn’t be cut. A ring saw can finish the corner cleanly with no overcut, leaving a perfect rectangle.
The other reason is depth in tight spaces. A 14-inch ring saw will cut roughly 270mm deep — deep enough for most reinforced concrete walls — and it only needs the working footprint of a hand-held saw to do it. That’s a big advantage in occupied buildings, basement conversions and any job where you can’t set up a tracked wall saw.
Who calls us for ring sawing?
Builders, M&E contractors, shopfitters, structural engineers and main contractors call us when they need precise openings cut in thick walls during fit-outs, refurbishments and alterations. We also handle domestic work — most commonly new doorways through concrete walls in flats, knock-throughs as part of renovations, and openings for steel beams during structural alterations.
Get a quote for ring sawing
Tell us the wall thickness, the size of the opening you need and the location, and we’ll come back to you with a quote. We work across London, Kent, East Sussex, Surrey and Essex with a fast response time from our Hastings base.