Suspended Timber Ground Floor Minimum Clearance

Hollow floors also known as suspended or timber floors are simply timber joists suspended across and supported by load bearing walls under the floor.

Suspended timber ground floor minimum clearance. Generally this is given as 550 mm minimum but it may be specified as a minimum dimension of 450 mm between the ground and the bottom of the joist which will give at least. This clearance must be increased to 200 mm where access space for termite inspection is required. So in what situations may minimum pile heights apply. It is necessary to allow adequate ventilation and ensure durability of the timber bearer.

And ground level paragraph 9 1 3 figure 65 and table 18. E2 as1 gives minimum heights of finished floor levels above ground for concrete slab floors and suspended timber floors the measurements depending on whether there is grass or paving outside. When the flooring of a suspended timber framed floor is particleboard nzs 3604 2011 timber framed buildings specifies a minimum clearance of 550 mm between the underside of the particleboard and the ground paragraph 2 3 7. Nzs 3604 sets a minimum height above ground for wood based products used for flooring.

At the turn of the 18th century when construction techniques moved from boarded floors installed directly on the ground to suspended timber floors over a ventilated chamber the innovation solved a significant problem. Table 18 gives minimum clearance distances depending on floor type either concrete or timber. Where a suspended floor is constructed with particleboard flooring product suppliers specify a minimum clearance between the underside of the particleboard and the ground. Minimum ground clearance height mm.

Ground moisture rising into or entering the subfloor space can create a damp environment which encourages timber rot fungus growth and the potential for termite activity. Have the ground beneath the suspended floor graded in accordance with open link in same page 3 1 2 3. The ends of these timber joists are built into or suspended by joist hangers from the external walls of the property. This standard is called termite management and it sets out a range of good building practices for avoiding termite attack and maintaining adequate subfloor ventilation.

Australian standard 3660 specifies the minimum clearance requirements between the ground and the underside of a subfloor. However paragraph 6 4 1 1 in nzs 3604 2011 allows a minimum pile height above finished ground level of 150 mm. Previously floor timbers had been prone to damp and rot thanks to their direct contact with the moist ground.