When you need a pipe to penetrate a roof you can’t just take off a tile and call it a day. You need to make sure that that area is totally secure against water ingress. The best way to do this is to use a lead flexi slate. These are lead sheets bonded with vulcanised rubber pieces in the middle. A hole can be cut in the rubber, allowing for the lead pipe to enter with a tight fit that can be made waterproof.
This article will explain how to install a lead slate. Please remember that both working at elevation and with lead is dangerous. Follow all standard lead safety procedures in respect to its toxicity. If you are not comfortable working on a ladder or roof or with lead, please hire trusted professionals for this project.
You Will Need:
- Safety goggles, safety gloves and a dust mask
- A flexislate, either slanted or flat
- A utility knife
- Patination oil
- Disposable brush
- Lead dressing tools – a setting in stick, bossing stick, lead dresser, and bending stick
If you are going to install the slate on a pitched roof you will need a slanted slate, if on a flat roof you will need a flat one. You will want to make sure the pipe is sticking through first.
Installing the Lead Slate
First, measure the diameter of the pipe and select one of the rings in the rubber that is slightly smaller than that diameter. Make an incision with your utility knife and carefully cut around that ring, separating a circular section in the middle of the rubber. This will allow the pipe to get through but only at a tight fit.
Push the slate over the pipe, and then, using the dressing tools, dress the lead to fit. Use the bossing and bending sticks to work it carefully over corners and the setting stick to force it into angles. Finally use the lead dresser to smooth the surface.Â
Now you can finish it off with the patination oil. Apply an even coat of patination oil to the surface area of the lead with a disposable brush.
