It is also made from a heavier material providing better fire protection.

They kept piling up the heavy material until it reached just below the top of the wall.

But if these buildings are used for the storage of heavy materials, it would make sense.

Only a few jackets were made of heavier material than what he was wearing.

Within a concrete building, the new room can be made of heavier materials.

Transport of these heavy materials to market was a key issue.

Now, she could see it was a piece of heavy, dark material, puffed up by the water.

She saw him pick up a long strip of heavy material.

On the other hand, heavy materials pose problems as well.

He said they found some heavy black material with the body.