After fitting together a stove pipe, it is important to seal it properly, in order to ensure that it is protected against smoke being blown back down the chimney. Sealing a stove pipe should be done before it is used for the first time, in order to protect users against smoke and ash inhalation, which can cause damage to lungs. As well as the danger of smoke being blown back down the pipe, if it is not properly sealed, you are more likely to risk drafts and cold entering the home through the pipe joints. Sealing your stove pipe can be done simply and easily, with just a few basic steps needed to keep the cold away.
Step 1 - Adding Joints to the Pipe
A very simple way of preventing smoke from blowing back down your pipe is by sealing the joints off with a second layer of pipe. This second layer is often described as a jointing accessory, or joint bracket, and it will basically form a barrier between the gaps in the pipe, and the room in which the stove pipe is being used. These joint accessories are cheap, and basic, but they do prevent most smoke and ash from arriving back in the room.
Step 2 - Blocking the Joints
For more persistent smoke, or if you are still feeling cold coming in through the joints, you can go a step further, and actually use rope and cement to form a protective seal. These components are not simple rope and cement, instead, you will need special non-combustible rope, and fire cement. Wrap the rope around the joints, until the join is completely covered, and then add a layer of fire cement over the top of the rope. Make sure that the rope is entirely covered and leave to set. If you have trouble getting the rope to fit tightly over the pipe, then you can thin it out a little with a wire brush or pack the gap using a mineral wool.
Step 3 - Gluing the Joints
Another alternative is to use a glue on the joints. High temperature silicone sealant is available which will prevent the joints from allowing smoke and cold into the room. You could try blocking up the gaps first, and then adding the sealant over the top, in order to prevent the glue from simply trailing down the outside of the pipe.
Step 4 - Fitting with Tar
Most stove pipes in the United States can be covered with a fire-resistant tar. This tar is contained on the pipes themselves, and so long as the pieces are fitted together properly, including being screwed into place, and then set the right way up (although the latter doesn't happen often), you should have a seal on your stove pipe which will resist all but the coldest and harshest of winds. If you are still finding that your stove pipe lets in a draft, then you should consider caulking the entire pipe against the wall and preventing the cold in that manner.