Installation Guide

The mansard is particularly well suited to
renovation work on pitched roof houses
because the upper story can be enlarged
without adding extra height to the structure.
The low downward slope of the mansard roof
line acts visually to reduce the scale of a
building and helps to eliminate a boxy
appearance. This technique is used frequently
on large commercial projects, particularly
those near residential neighborhoods. It is
also a common solution to the problem of
avoiding a monotonous appearance on flat-
roofed frame apartment buildings.
Properly used, a mansard roof can strengthen
the design without substantially increasing
construction costs. If raised up above the level
of a built-up roof the mansard can screen out
roof penetrations or mechanical equipment.
The variety of mansard roofs is practically
infinite. One of the most widely used (and
misused) roof designs, its proportions and
scale are very important and care should be
taken to avoid a mansard roof line that is
either too skimpy or too generous.
Two of the most widely used roofing
materials on the mansard roof are Certi-label
cedar shakes and shingles. Cedar shakes, with
their heavier texture and solid appearance,
are perhaps more frequently specified for
mansards although shingles are also used,
particularly when a lighter scale is desired.
The light weight and ease of application of
Certi-label shakes and shingles contribute
substantially to economical construction.
Construction details for typical mansard roofs
are shown in Figure 6.
MANSARD ROOF DETAILS
Figure 6: Mansard Roof
Photo: Murray Levin
6
Eave protection
min. 36"
Product should project
1 1/2 beyond the fascia
and approximately 1"
over the gable or rake end
"
Certi-label shakes
Two nails (only) for each
shake approximately 3/4" from
edge and approximately 1 1/2"
above exposure line.
Plywood Sheathing
The bottom edge of the felt should be
positioned above the butt of the
shake at a distance equal to
twice the weather exposure.
Never interlay shingles with felt.
Space shakes 3/8"
to 5/8" apart