Abstract: A vertical spigot joint for sealing the space between the socket and the end of a pipe inserted in the socket has an aluminium cord sealing the space and a filler mixture. The filler mixture comprises aluminium cement, vermiculite grains and a plastics material which retains its plastic properties in use. A sleeve of a glass fibre cloth coated with protective layers covers the joint and is secured to the pipe end and socket by silicone putty and by clamping strips. A thermally insulating refractory ceramic felt is provided between the pipe end and the filler material. The use of this filler mixture, together with the provision of the sleeve enables a joint to be produced which is gas-tight and absorbs relative movement of the pipe end and socket due to the media in the pipe or due to thermal expansion and contraction.