Repointing of historic stone or brick foundations must match the original mortar in color, texture, composition, and Joint profile. Older brick and stone are softer than modem hardfired brick, so mortar used on historic buildings should be relatively soft. A cement harder than the masonry will not expand and contract at the same rate and may cause masonry to spall and crack.

Existing foundations should never be covered with cement or plaster, and never painted. Water will be trapped inside and the resulting freezing and thawing will accelerate the deterioration of the wall. When possible, existing "parging" or paint should be removed. (The exception would be those houses which originally had plaster front facades to imitate stone veneer.)