DEAR SAM: Almost the entire entrance wall of our split-foyer house is single-pane glass. To improve the insulation, we considered installing glass blocks beyond the panes next to the door. What is the insulation value of glass blocks?
ANSWER: Insulation block and dual glazing have about the same resistance to heat flow, but in your case you would still need better insulation for the remaining single pane.
Glass block and masonry insulation would cost more. Remember that masonry joints and thick perimeters of glass are conductors, so insulating joint sealer should be used between the blocks except for the exterior/interior mortar joints (about one inch).
Visit a glass company to see the types of glass available in transparent or translucent, 3/16ths-inch thickness for installation over all the existing glass.
This may be mounted in thin wood frames, which permit a half-inch of "dead air" -- equal to the insulation of storm windows -- when attached to the window sash. Ornamental designs would reflect the sun away from your foyer.
DEAR SAM: The entrance hall of my house is laid with red ceramic tile, which is covered with scuff marks. How do I restore the ceramic glazed finish?
ANSWER: If the marks are from rubber heels, they can be removed with medium steel wool. If the surface is really glazed and the surface has been cut or scratched, the steel wool should remove the imbedded grime. A coat of Johnson's Kleer should maintain the floor for some time.