And the weight of the nails was fifty shekels of gold. And he overlaid the upper chambers with gold.

And the weight of the nails was fifty shekels of gold. And he covered the upper chambers with gold.

and the weight of the nails is fifty shekels of gold, and the upper chambers he hath covered with gold.

And fifty shekels weight of gold was used for the nails. He had all the higher rooms plated with gold.

Then he also made nails of gold, such that each nail weighed fifty shekels. Also, he covered the upper rooms in gold.

The upper chambers - Compare 1-Chronicles 28:11. Their position is uncertain. Some place them above the holy of holies, which was ten cubits, or fifteen feet lower than the main building (compare 1-Kings 6:2, 1-Kings 6:20); others, accepting the height of the porch 120 cubits 2-Chronicles 3:4, regard the "upper chambers" or "chamber" ὑπερῷον huperōon, Septuagint), as having been a lofty building erected over the entrance to the temple; others suggest that the chambers intended are simply the uppermost of the three sets of chambers which on three sides surrounded the temple (see 1-Kings 6:5-10). This would seem to be the simplest and best explanation, though we cannot see any reason for the rich ornamentation of these apartments, or for David's special directions concerning them.

The weight of the nails was fifty shekels - Bolts must be here intended, as it should be preposterous to suppose nails of nearly two pounds' weight.
The supper chambers - Probably the ceiling is meant.

Nails - Each of the nails, screws, or pins, by which the golden plates were fastened to the walls, weighed, or rather was worth, fifty shekels, workmanship and all. Upper chambers - Rather, the roof.