Rytons Underfloor Ventilation Calculator

For effective sub-floor ventilation:
  • Save time by using this handy calculator to work out how many Rytons Periscope Vents with Rytons Multifix Air Bricks are required for suspended timber or block and beam floors.
  • Ventilate the underfloor space by providing ventilation in two opposing external walls.  Ensure ventilation has a free and unobstructed path to all areas by making provision for ventilation air to pass through sleeper walls and other sub-floor obstructions.
  • Position ventilation clear of where hard landscaping and vegetation is likely to finish.
  • If flooding is a risk consider using Rytons Vertical Extension to raise the height of the Periscope by up to 1m above ground level.  This may prevent low-level flooding and give the property a little more time against higher flood water.  Note: Flood water deeper than 1m should be allowed into the property to relieve pressure on the walls.
  • Buy or specify Rytons by name.  Alternative products may have lower rates of ventilation which could leave the sub-floor under ventilated.  Find NBS Plus specifications for Rytons Periscope Underfloor Ventilator (PUFV), Rytons Multifix Air Brick (MFAB) and Rytons Periscope Vertical Extension (PUFVVEXT) below.

Make a calculation for the use of Rytons Periscope Underfloor Ventilator with Multifix Air Brick:

Total Floor Area (m2):   
Run of Exterior Wall (m):   


Rytons is proud to be a family run business and British manufacturer since 1972.