Danskin
 

Selecting the appropriate system

1. The basic system height without packing should be able to fit between the high point in the subfloor and the desired Finished Floor Level (FFL). Packers and, where necessary, elevating blocks are then used to level out areas below the high point.

Basic system height

2. To calculate the basic system height determine the size of the void needed beneath the floor boarding by considering the height of services which will run in the void. Remember that service pipes may need space to cross over each other and that in the worst case this could occur at the high point of the tolerance in the subfloor. Add the thickness of the preferred floor boarding to give the basic system height.
(N.B. If the floor is to comply with Robust Details the void allowed must be at least 50mm.)

Calculate the basic system height

3. Double check that the basic system height at the high point will marry in with other fixed points in the building such as stairs, corridor screed levels or the thresholds of patio doors.

4. From the table below select the basic system height and floor boarding closest to (but not more than) your needs. Packing will make up any difference.

Basic System Height

Floor Boarding

Support Bearer Height (Nominal)

Saddle Type

Support Bearer Centres (mm)

Saddle Centres

RD - FFT2?

51mm

18mm Chipboard

22mm

11mm Small

400mm

300mm

No : too low

55mm

22mm Chipboard

22mm

11mm Small

600mm

300mm

No : too low

65mm

18mm Chipboard

36mm

11mm Med.

400mm

450mm

No : too low

69mm

22mm Chipboard

36mm

11mm Med.

600mm

450mm

No : too low

74mm

18mm Chipboard

45mm

11mm Med.

400mm

450mm

Yes

78mm

22mm Chipboard

45mm

11mm Med.

600mm

450mm

Yes

81mm

18mm Chipboard

52mm

11mm Large

400mm

600mm

Yes

85mm

22mm Chipboard

52mm

11mm Large

600mm

600mm

Yes

90mm

18mm Chipboard

61mm

11mm Large

400mm

600mm

Yes

94mm

22mm Chipboard

61mm

11mm Large

600mm

600mm

Yes

The above table is based on a Uniformly distributed load of 1.5kN/m2 and Concentrated load of 1.4kN as specified for self contained, single family dwelling units in BS6399-1:1996. Exceptional loads (such as storage heaters) may require support direct from the subfloor. It is also recommended that in high load areas such as kitchens and bathrooms support bearer centres are reduced to 300mm. Communal areas in blocks of flats such as corridors and vestibules will require special consideration. Danskin can provide centres for other floor boarding and types of use.

© J Danskin & Co. Ltd. 1 Netherton Road Wishaw ML2 0EQ T: 01698 356000 F: 01698 372222 E: [email protected]