Unpolished, unfinished wood planks, glass wool (use as last resort), or nylon fiber are three alternatives which can be used to seal gaps. Thickness of floors, walls also matters for sound to radiate through. Cheapest alternative is of course paper as the best sound absorbent paper. Unlaminated newsprint is the best.

hi the best material for bathroom doors is FRP. COMPLETELY WATERPROOF. For more premium segment ABS doors are good. ABS is highly engineered plastic doors with WPC frames. All materials used except the wood used in lock body is water proof. Both doors and frames come laminated . Pic :ABS door.

Dear Mr. Dinesh, Since you are looking for securiity with aesthetics, you need to incorporate a security grill in form of a geometric lattice/ jaali. You can choose between SS/MS or corten steel to do that. Second, you need light and ventilation along with weather proofing. Hence, it would be a really good option to go for anodized aluminium doors/ WPC doors which would be cost effective and decorative as well.

hi, you can opt for 1.wooden(teak or sheesham) pu polish or melamine finish- these solid wood have grains which look good) 2.wpc doors- these are latest tech. in industry you can go for ... fire resistant, water proof 3.PVC doors 4.plyboard with veneer(pu or melamine on it)or laminate