(See Note A-9.13.4.3.)
(1)
Floors-on-ground shall be provided with a rough-in for subfloor depressurization consisting of
(a)
a gas-permeable layer, an inlet and an outlet as described in Sentence (2), or
(b)
clean granular material and a pipe as described in Sentence (3).
(2)
The rough-in referred to in Clause (1)(a) shall include
(a)
a gas-permeable layer installed in the space between the air barrier and the ground to allow the depressurization of that space,
(b)
an inlet that allows for the effective depressurization of the gas-permeable layer, and (See Note A-9.13.4.3.(2)(b) and (3)(b)(i))
(c)
an outlet in the conditioned space that
(i)
permits connection to depressurization equipment,
(ii)
is sealed to maintain the integrity of the air barrier system, and
(iii)
is clearly labeled to indicate that it is intended only for the removal of radon from below the floor-on-ground.
(3)
The rough-in referred to in Clause (1)(b) shall include
(a)
clean granular material installed below the floor-on-ground in accordance with Sentence 9.16.2.1.(1), and
(b)
pipe not less than 100 mm in diameter installed through the floor, such that
(i)
its bottom end opens into the granular layer required in Clause (a) at or near the centre of the floor and not less than 100 mm of granular material projects beyond the terminus of the pipe measured along its axis, (See Note A-9.13.4.3.(2)(b) and (3)(b)(i))
(ii)
its top end permits connection to depressurization equipment and is provided with an airtight cap, and
(iii)
the pipe is clearly labeled near the cap and, if applicable, every 1.8 m and at every change in direction to indicate that it is intended only for the removal of radon from below the floor-on-ground.