Pipe shutter
Also called Instant Pipe Shutter, Waste pipe shutter, Soil pipe shutter
A pipe shutter is a shutter formed around a pipe passing through a concrete floor, so that the oversized opening around it can be filled with concrete without the pour running away into the void below. Service holes in precast and in-situ floors are deliberately formed larger than the pipe to give installation clearance, and that annular gap has to be closed before it can be backfilled and sealed.
From our specifications
Ours is the Instant Pipe Shutter, and its shape describes the problem it solves. It is a two-piece plastic shutter that clips around a standard 110 mm diameter waste or soil pipe and shutters the complete circumference, moulded from recycled polypropylene and reusable across pours, with an extension component for larger formed openings. It goes on without power tools — clipped together, secured with a bolt and wing nut, then pulled into position on cable ties — which is the whole point, because the method it replaces is cutting a circle out of a board with a jigsaw, drilling it and screwing it down, often off a ladder. Polypropylene is not an organic material, so unlike a timber shutter left in place under a suspended ground floor it will not rot, and it is supported off the slab rather than propped from below.
Source: Instant Pipe Shutter (IPS) published product data and datasheet
Where it matters on site
The shutter is not the seal, and conflating the two is the mistake worth avoiding. Its job is to form a clean, accurately sized opening that can be filled properly; what makes the penetration compliant is the fire-stopping and sealing detail specified for that floor — a fire collar and backfill on an upper floor, a full-depth seal on a ground floor — and that detail belongs to the designer and to the Building Regulations, not to the shutter. What a consistent shutter buys is that the specified detail can actually be installed as drawn. An opening backfilled around a splayed timber offcut, or foam-filled because nobody could shutter it neatly, is the version that fails inspection and gets cut out again. On upper floors there is a second gain worth putting in the method statement: pre-installing the shutters before the deck is loaded removes work at height that the timber method creates.