__________ material is made of black polythene having a thickness of about. 50 mm to 1 mm.
(a) Brick
(b) Stone
(c) Plastic sheet
(d) Cement concrete
I had been asked this question in a job interview.
This key question is from Dampness in chapter Damp Proofing, Water Proofing and Termite Proofing of Construction & Building Materials