Roof Slope Features

How should soil vent pipes be tested?

As part of the testing procedure for a soil vent pipe from the main drain to the point of termination, an air test is required to ensure there are no leaks in the pipes that may result in noxious smells seeping into the building. An airtight pipe bung is placed into the top of the soil pipe and air pumped into the pipe to create a positive pressure. The pressure is monitored over a short period of time for a return to normal. If it does so quickly it fails the test.
With RedLine Vent Tiles and Ridge Vent Terminals it is not possible to install a pipe bung from the roof. The flexible pipe must be disconnected from the vent and pipe bung installed in the spigot. The flexible pipe is then reconnected. Following completion of the test the pipe bung is removed and flexible pipe reconnected.


Is there a limitation for ThruVent as a terminal for soil vent pipes?

There are no restrictions when using our high capacity 8.8k ThruVent Tile or Hi-Flow ThruVent (or Ridge Vent Terminals) for soil ventilation. However, when using our 4.5k ThruVent its use for soil ventilation is limited to single and two storey housing. BS EN 12056-2: 2000, which covers sanitary pipework, requires soil vent pipes, except for single occupancy houses up to two storeys, to maintain the diameter of the pipework above the highest connection to the outside air. As 4.5k ThruVent Tiles have a spigot diameter of 75mm they are not suitable for connecting to a 100mm diameter soil pipe in these instances.


Is it acceptable for a main roof to discharge onto a lower roof?

BS 5534: 2014: Slating and tiling for pitched roofs and vertical cladding - Code of Practice specifically discourages the design of discharging rainwater from one roof onto another. Collecting water from a large roof area into an inclined valley, which then discharges back onto the roof, can also cause problems. In both cases the concentration of water could be greater than the tiles are designed to withstand resulting in water being forced through the side laps or interlocks of the tiles.