February, 1917 
55 
WEATHERPROOF WALLS FOR THE TIMBER HOUSE 
Types of Sheathing, Paper and Siding that Withstand 
the Weather and Make for Variety of Appearance 
ERNEST IRVING FREESE 
C LOTHING the structural frame¬ 
work of the outer walls of a 
timber house involves three dis¬ 
tinct and separate operations: 
First, the bare timber skeleton of 
the exterior walls is entirely covered, 
outside, with boards nailed securely to 
the framework. These boards are 
known collectively as sheathing. 
Second, heavy waterproof building 
paper is laid over the entire sheathed 
area as an insulation. 
Third, the “weather-facing” or “sid¬ 
ing” is applied. This siding is the 
outermost garment of the wall, and is 
therefore exposed to view. It may be 
of wood, masonry, stucco, or possibly 
a combination of any two or all three 
of these materials. 
The paper membrane, sandwiched be¬ 
tween the sheathing and the siding, is 
a highly essential part of the wall con¬ 
struction. Especially is this so as re¬ 
gards the weather excluding and non- 
conductive properties of the wall. The 
paper effectively stops air currents, pre¬ 
vents moisture from penetrating the 
wall, and, if it is of a non-combustible 
material such as asbestos felt, the 
qualities of fireproofness and ratproof- 
ness are added. Rosin sized building 
paper should never be used, for it is 
neither waterproof nor an efficient insulator. 
There are a number of excellent waterproof 
papers available for use. as well as the asbestos 
felt already mentioned. 
The Paper and Sheathing 
Requisite qualities in building paper are tough¬ 
ness, imperviousness to air and water, cleanliness 
in handling, and lack of objectionable odor. The 
cost of the best is a mere nothing in comparison 
with the many benefits derived from its use. For 
upon this thin film of paper, midway between 
sheathing and siding, depends, to an unguessed 
The under coat of sheathing 
and gaper should in itself 
make a weatherproof wall 
Six types of horizontal outer 
boarding which offer varied 
effects. “A” is noio obsolete 
at the sill of the building and working 
upward toward the rafter plate. Only 
the upper edge of each sheet should be 
secured to the sheathing. Each suc¬ 
ceeding sheet should have an ample 
lap —; say 3" — over the sheet below. 
Thus' the lower edge of each sheet, in 
turn, covers the tacks that hold the pre¬ 
ceding sheet in place. Particular vigi¬ 
lance should be exercised to see that 
the paper is fitted snugly and neatly 
around all openings for doors and 
windows. Every inch of sheathing 
should be covered, and not one tack 
should be visible, except where the 
paper is turned inward and secured 
against the flat faces of the timbers 
that frame the openings for the doors 
and windows of the house. 
Horizontal Boarding for the Outer 
Surface 
Wooden siding may be conveniently 
divided into three natural groups, com¬ 
prising horizontal boarding, vertical 
boarding, and shingles. Of the various 
forms, those applied horizontally are by 
far the most numerous. The well- 
known clapboard was originally a 
product peculiar to the New England 
States, and may be taken as a type of 
horizontal siding. It was the chief 
covering material for the oldrfashioned frame 
houses of Colonial days. 
The cross-sectional view of clapboards, at “A” 
in Sketch 2, shows that each individual board 
must necessarily be held in place by two widely 
separated rows of nails; one row near the at¬ 
tenuated upper edge of the board, and another 
row close to the thicker and lower edge. Neither 
edge is free to move. Therefore, the natural 
tendency of the board to shrink or swell is inter¬ 
fered with. For this reason the tendency to 
shrink often causes the board to split apart, 
{Continued on page 72) 
The plain surfaced white plaster house lacks 
the variety of clapboard siding. It depends for 
optical relief upon its shingles and shadoivs 
The requirements for vertical siding are differ¬ 
ent from those for horizontal work. All these 
types are good 
extent the well-being of the house and the com¬ 
fort and health of its inhabitants. 
The paper should invariably be applied on a 
solid backing in order that it may fulfil its mani¬ 
fold purpose and be preserved against displace¬ 
ment and destruction. Here, -then, is the main 
reason for the first mentioned operation: the 
wooden sheathing affords a suitable foundation 
upon which to lay the weather excluding and non- 
conductive membrane of building paper or 
asbestos felt. The sheathing also performs a 
secondary service by stiffening the framework of 
the walls—especially if it be laid diagonally from 
sill to rafter plate and securely nailed to all 
members of the timber skeleton. This sheathing 
need not be of expensive lumber, but it must be 
sound and reasonably dry, and mill planed to a 
uniform thickness. The hoards should not ex¬ 
ceed 6" in width, nor should they be less than 14," 
thick. It is well to lay the boards apart, one from 
the other, a distance equal to the thickness of the 
carpenter’s two-foot rule. 
Soon after the sheathing of the framework is 
in place, the paper should be applied. It should 
be laid in successive horizontal hands, beginning 
Here is seen to the full the decorative value of 
exterior tvood. in breaking up lohat would other¬ 
wise be a somewhat monotonous surface 
