Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to insulated wall coverings used on
veetical suefaces of building structures and generally designed
to simulate wood clapboard. Such coverings are commonly
referred to as "siding".
It is common practice to cover vertical surfaces of both
new and old building structures with horizontally extending
panels which interlock vertically with one another. Materials
used include steel or aluminum coated with an enamel exterior
finish as well as extruded synthetic plastic. After assembly
the resulting siding gives the appearance of wood clapboard, but
because the material has a durable finish, it has the advantage
that it is essentially maintenance free.
With recent increased interest in energy conservation,
there has been more use of insulation material positioned under
the siding. This insulation is commonly made up of shaped
boards which are positioned under the siding. Such insulating
boards are commonly called "backer boards". The resulting wall
covering enhances the insulating qualities of the wall without
affecting the pleasing appearance of the siding.
It is well recognised that after installation the wall
covering must be capable of withstanding minor impacts and the
panels must remain in position in heavy wind. Also the panels
should resist rattling and wherever possible remain firmly
positioned during movements caused by temperature fluctuations.
However it is not always appreciated that some of the problems
arising with installations of siding originate with building
shrinkage. Shrinkage occurs vertically in many building
structures and it is caused ~oth by compressive forces and by
wood shrinkage in a direction across the grain of the wood a~
floor and ceiling joists. Such shrinkage is particularly
pronounced in new buildings where the transverse members such as
floor and ceiling joists dry and shrink significantly with aye.
As a result the vertical extent of the outer surface of the
building structure is effectively reduced and there is then a
tendency for the siding panels initially to become looser and to
rattle in the wind, and then in some cases to become disengaged
from one another. Such disengagement occurs mainly at the first
floor level or at the bottom of the siding where the
installation was started. Subsequently it can be re-connected
properly only by first disassembling the remaining siding and
then re-applying it to the building structure.
The present invention is embodied in several aspects all of
which are directed to providing an improved insulated wall
covering and more particularly one which better resists rattling
and separation caused by building shrinkage.
The invention will be better understood with reference to
the drawings, in which:
FIGURE 1 is a sectional view of a lower part of a new
building structure and showing a starter strip according to one
embodiment of the in~ention as well as a first embodiment of
wall covering used with the starter strip;
FIGURE 2 is a sectional view similar to Figure 1 and
showing two other embodiments of a wall covering assembled at
the second floor level of a two-storey structure;
FIGU~E 3 is a view similar to Figure 2 and showing
alternative embodiments incorporating parallel-sided backer
boards;
FIGURE 4 is a more general view than that shown in Figure 2
and illustrating two further embodiments of wall covering using
support elements and parallel sided backer boards;
FIGURE 5 is a view similar to Figure 4 and showing yet two
more alternative embodiments of wall covering according to the
invention;
FIGURES 6 and 7 are views similar to Figure 5 and showing
starter boards for use with the Figure 5 wall coverings;
FIGURE 8 is another view similar to Figure 4 and showing
one more embodiment of the invention having an alternative to
the backer board shown in Figure l;
FIGURE ~ shows a starter board for use with wall coverings
such as that shown in Figure 1.
Reference is first made to Figure 1 which shows a wall
covering 20 assembled on a new building structure 22which is
conventional in form and includes a foundation 24, plate 26,
floor joists 28 covered by end piece 30, plywood floor 32, and
wall structure 34. The outer surfaces of end piece 30 and plate
26 are sometimes covered first with a sheathing but in this
illustration the siding is applied directly to these parts.
The siding 20 includes a bottom starter strip indicated
generally by the numeral 38 and attached by a nail 40 passing
through the strip and into the plate 26. The starter strip 38
is first attached to the building structure and then a tapered
backer board 41 and an edge structure of a siding panel 42 are
positioned on the strip and located using a nail 44 which is
engaged in the end piece 30. A further siding panel 46 has an
edge structure similar to that at the bottom of panel 42 and
this is inter-enga~ed in a second edge structure at the upper
extremity of panel 42. This conventional inter-engagement
structure is known in the art as a "Pittsburgh lock". Panel 46
is associated with a further backer board 47 and it will be
appreciated that further panels and backer boards are provided
sufficient to cover the surface of the building structure.
Returning to the starter strip 38, it will be seen that the
strip consists of an upwardly-extendi.ng nailin~ flange 48
through which the nail 40 passes, an S-shaped portion 50
dependent from a lower extremity of the flange 48 and extending
generally outwardly, and an outwardly and downwardly inclined
ramp 52 dependent from the S-shaped portion 50. The S-shaped
portion 50 and ramp 52 combine to form a leg which terminates at
a step 54 extending outwardly from the bottom of the ramp 52 to
support a lower extremity of the backer board 41. The S-shaped
r ~
portion 50 of the starter strip is provided to permit deflection
of the step 54 downwards with reference to the flange 48 and
nail 40. More generally the leg can take any form which would
permit downward movement of step 54 without disenyagement from
the panel 42.
It will be seen in Figure 1 that the backer board 41 sits
on the step 54 of the strip 38 and also that the nail 44 passes
both through the panel 42 and through the backer board 41.
Consequently the relative positions of these two parts are
defined. Also, the backer board 41 includes a downward
projection 56 resting on the step 54 and the step is retained
inside a land 58 dependent from a bottom end of a main portion
60 of the panel 42. The land 58 forms part of the edge
structure and projects rearwardly terminating at an inwardly or
upwardly dependent lip 62 positioned behind the step 54. It
will be seen that the projection 56 combines with the land 58
and lip 62 to retain the step 54 in position. Any downward
movement of the panel 42 will be absorbed by deformation of the
S-shaped portion of the starter strip without disengagement of
the panel from the starter strip.
The land 58 and lip 62 form part of a Pittsburgh lcck which
is shown fully at the top of panel 42. The further panel 46
includes a land 64 and lip 66 combining with a downwardly-
opening channel 68 formed by a fold 70 in the panel 42. This
panel terminates at a nailing flange 72 which projects upwardly
fLom the fold 70 in line with the main portion 60 of the panel.
It will be evident that the panel 46 is engaged in the panel 42
by moving the panel 46 upwardly so that the lip 66 engages in
the channel 68. The panel 46 and backer board 47 can then be
retained in position using a nail in a similar manner to nail 44
which ho~ds panel 42. Also, the backer board 47 behind panel 46
is engaged in the same manner as the backer board 41 previously
described.
Returning to the backer board 41, it will be seen that at
its lowest extremity adjacent the projection 56 a lower surface
or shoulder 74 is formed and that the rear face 76 of the backer
board is coplanar with a similar rear face 78 of the`backer
board 47. This can be advantageous when covering a building
having clapboard elements because the flat rear surface
presented by the backer board tends to extend across the
irregularities of the clapboard and simplify the assembly of tbe
siding. Also on new buildings the shape effectively fills the
space available providing better insulation because there is no
significant space to permit convection of heat caused by air
moving upwardly in space behind the siding.
After a structure such as that shown in Figure 1 has been
assembled, it will be evident that if the building structure
parts previously described were to shrink, then there would be a
distributing force extending vertically between the backer
boards tending to maintain the vertical extent of the siding
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6~;
irrrespective of the shrinkage of the building. For instance if
the joists 2~ and end piece 30 were to shrink, the floor 32
would drop towards the foundation 24 and parts of the siding
above the floor would tend to be carried with them. The panels
and associated backer boards move in unison because the force
would be transmitted by the lower surface of backer board 47 to
the upper surface of backer board 41. This board would then
te~d to cause deflection of the backer board 41 and panel 42 and
this deflection would be absorbed by the starter strip 38
without separation. Similarly, because of this transmission of
force the position of lip 66 in the channel 68 is retained
thereby eliminating the possibility of separation caused by
shrinkage.
In order to ensure this relationship, the exposed front
surface of each panel after assembling will be substantially
equal in vertical extent to the space between upper and lower
sur~aces of each backer board.
The foregoing discussion of shrinkage can be extended to
the whole surface of a building structure. It will be eviden~
that there will be a tendency for the walL covering to settle
into a new position after shrinkage and that not all of the
siding panels will move downwardly. This is because the wall
covering can be considered to be a rigid structure held in
position by a plurality of nails having some flexibility. It
will be evident that any force results in a reaction and that if
the forces toward the bottom of the wall covering resist further
downward movement the rigidity of the covering will result in an
upward displacement of the upper part ot the covering relative
to a portion of the building. In effect as the building shrinks
some of the wall covering will tend to remain in position held
there by lower parts of this covering with the result that it
~ould appear that there has been slight upward movement at the
top and downward movement at the bottom. It must be emphasi~ed
that these movements are quite small but that because the
Pittsburgh lock relies on an inter-engagement o~ about 1/4"
under ideal conditions it will be evident that without this
force distribution by the backer board it would be possible for
the siding panels to become loose and to rattle and that in
extreme instances some of the panels will separate. ~sing the
present wall covering the inter-engagement between siding panels
is retained so that rattling is reduced and separation
eliminated while at the same time expansion and contraction
caused by temperature changes can take place unimpeded by the
force transmission between backer boards.
It should also be appreciated that the projection on the
backer board engages the land of the associated panel so that
any downward force on the backer board is trans~itted to the
panel to pull the panel with the backer board. This also serves
to ensure that the panel and backer board retain the same
relationship. Of course, in the inexact art of installing
.
siding there may well be some initial looseness betw~en panels
and between backer boards but this will not be allowed to
increase and will be taken up when the building shrinks. For
the purposes of this application the panels and backer boards
are shown in the drawings in positions they will reach when the
forces are transmitted. These a~e the critical positions which
will be described and referred to in the claims.
Reference is next made to Figure 2 which illustrates two
alternative embodiments of wall covering shown built on an outer
surface of a new building structure and also using tapered
backer board. In the lower of these embodiments the upper edge
or locking structure of a panel 80 is inter-engaged with
complementary lower edge or locking structure of a lower part of
a panel 82 at a lock which differs slightly from the
conventional Pittsburyh lock. Although the lower edge structure
of panel 82 is similar to that used in a Pittsburgh lock, the
panel 80 includes a channel 84 recei~ing a lip 86 of panel 82.
Also a step 88 is formed adjacent channel 84 to act as a support
for a projection 90 of a backer board 92. This step is adjacent
a nailing flange 94 of the panel 80 so that any downward force
caused by the backer board 92 is transmitted by the projection
90 direc~ly to the panel 80. This contrasts with the
arrangement shown in Figure 1 in that the backer board 92 is
transmitting a force directly to the panel 80 instead of to the
associated panel 82. As a result backer board 92 pushes both
the panel 80 and the backer board 96 simultaneously.
An alternative embodiment is shown at the top of Figure 2.
Again a lower end of a panel 98 is of conventional Pittsburgh
lock construction and it combines with a channel 100 formed by a
reverse bend 102 having a leg 104 terminating in a step 106
which rests inside the land 108 of the Pittsburgh lock
structure. A nail 110 passes both through the leg 104 and
through a main portion of the panel 82 and a backer board 112
has a projection resting on the step 106. Also, board 112 is in
engagement with an upper extremity of backer board 92 so that,
as drawn, any downward force in the backer board 112 is
transmitted directly to the panel 82 and to the backer board 92
simultaneously in a similar fashion to that of the embodiment
shown at the bottom of Figure 2.
The embodiments discussed so far require backer boards
which have sufficient width at their lower extremities to engage
on another backer board. In some instances parallel sided
backer boards will be used and embodiments capable of using such
backer boards are shown in Figures 3 and 4.
Reference is next made to Figure 3. Parts corresponding to
those described with reference to Figure 2 will be given
corresponding primed numerals. In this embodiment
parallel-sided backer boards 96', 92' and 112' are contained
behind respectiYe panels 80', 82' and 98'. However panel 80'
differs from panel 80 (Figure 2) in ~hat the upper edge
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structure of panel 80' also includes a re~rwardly-extending cap
109. Consequently downward forces ~rom backer board 92' are
transmitted to panel 80' at step 88' and also by way of cap 109
to backer board 96'~ This arrangement permits the use of
standard parallel-sided backer boards.
The upper part of Figure 3 shows an embodiment which
differs from that of the lower part of Figure 3 in that a cap
111 is formed differently as part of a different edge or locking
structure. Otherwise the panels and backer boards co-operate in
similar fashion to prevent separation.
Reference is next made to Figure 4 to describe a lower one
of two embodiments which are for use in conjunction with a
conventional Pittsburgh lock between panels 114, 116 having
respective backer boards 118 and 120. The lower èxtremity of
backer board 120 is located in contact with panel 116 and
supported by a load transfer strip 122 which could either be
continuous or take the form of a series of clips. The strip 122
defines a step or support ledge 124, a nailiny portion 126
extending upwardly from t~e ledge 124 and terminating in a cap
128 resting on an upper extremity of the backer board 118 and
panel 114. Consequently forces are transmitted from backPr
board 120 to strip 122 and hence to panel 114 and backer board
118.
The upper embodiment shown in Figure 4 is particularly for
US2 where the strip has a cap bearing only on the backer board
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and not on the panel. As shown, a backer board 130 is
associated with a panel 132 which is engaged with panel 116 in a
conventional Pittsburgh lock configuration. The lower end of a
backer board 130 rests on a step 136 adjacent land 134~ The
step 136 is part of a load teansfer clip or strip 138 which
includes a cap 140 sitting on the upper extremity o~ the board
120. It will be evident that downward force from the backer
board 130 will be transmitted to the step 136 which in turn will
transmit the force firstly to the bottom of panel 132 so that
this panel will move with backer board 130 and also by way of
cap 140 to the board 120. Again such an arrangement will
prevent separation of the panels upon shrinkage of the building
structure.
Reference is next made to Figure 5 which illustrates an
adhered backer board arrangement using conventional Pitksburgh
locks. At the lower part oE Figure 5 an embodiment is shown in
which a Pittsburgh lock 144 is provided between a panel 146 and
a further panel 148. Panel 148 has a tapered backer board 150
attached to it and projecting upwardly beyond the Pittsburgh
lo~k 144. Similarly, a backer board 152 is associated with
panel 146 and the boards 150, 152 abut with one another as
shown. Although this arrangement of backer boards facilitates
assembly, the backer board can be terminated immediately above
the Pit~sburgh lock. Such arrangements all take advantage of
the inventive characteristics of previously described panels in
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which the backe~ boards are of the drop-in type. Onc~ the panel
148 has ~een assembled, panel 146 and attached backer board 152
are positioned by initially engaging the backer board 152
against backer board 150 and sliding the panel 146 upwardly to
S engage the Pittsburgh lock 144. At this point the backer board
152 can be moved towards the building structure and into the
position shown. Any downward force from the panel 146 will then
be transmitted directly by backer board 152 to the backer board
150 and hence to the panel 148. Consequently the Pittsburgh
lock will remain in firm engagement.
In the upper part of Figure 5 a simplified Pittsburgh lock
arrangement is also shown without the nailing flange normally
used with this type of lock. Nailing is provided directly
through the insulation which is provided by a backer board 154
which has a projection 156 extending below the upper extremity
of backer board 152. The principle of operation is the same as
the embodiment shown at the bottom of Figure 5 but the resulting
insulation and rigidity may make this embodiment more desirable
than that shown at the bottom of Figure 5.
A suitable starter arranyement is shown in Figure 6 for the
lower embodiment illustrated in Figure 5. In this starter
arrangement a small backer board or starter board 151 is
attached to a building structure 153 to fill the space below
full backer board 155 attached to panel 157. The starter board
151 is shaped to give some clearance for the head of a nail 159
~ . .
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which is engaged in a vertically orientated slot 161 of the
board 151. Also, the board 151 defines a downwardly-openiny
recess 163 containing a lip of the Pittsburgh lock of panel 157.
In use the board 151 is first attached to structure 153
using nails 159 positioned in slots 161 to permit vertical
downward movement of board 151~ Structural shrinkage will cause
board 155 and panel 157 to move in unison so that board 155 will
push board 151 downwardly thereby maintaining engagement between
panel 157 and board 151.
If pre-ferred the exposed lower extremity of board 151 can
be covered, treated with weatherproof material, or made entirely
from such material.
Figure 7 also shows a starter board which in this case is
to be used with the upper embodiment shown in Figure 5. A board
165 is shaped to fit under a full board 167 an~ co-operates with
a panel 169 in similar fashion to panel 157 and board 151
(Figure 6). However the board 165 is also shaped to receive a
weatherproofing cover 171 of syntheti.c plastic material or of
metal. It will be appreciated that t:he board 165 can be formed
of relatively rigid weatherproof materials such as extruded
vinyl, fibrous materials, wood, metal, or foamed plastic
materials.
When using a drop-in backer board, the embodiments such as
those shown in ~igures 1 and 2 require a backer board which nas
a preferred orientation. Where it is desired to use
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parallel-sided backer board for economy, backer board such as
that shown in Figure 8 can be used. As seen in Figure 8 a
Pittsburgh lock arrangement 15~ is used between panels 160 and
162 and that ~he drop-in backer board behind panel 1~2 is made
up of a first part 164 which is attached by gluing ~or an
equivalent process) to a similar second part 166. Parts 164 and
166 are inverted relative to one another so that as can be seen
from similar parts 168, 170 of the board associated with panel
160, a downward projection 172 formed by part 168 is duplicated
by the rearward part as indicated at the top of part 166.
Consequently these boards are symmetric and can be placed behind
a panel irrespective of their orientation. However it will be
appreciated that an air space will exist between the panels and
the building structure and that where it is desired to use a
drop-in backer board without air space on a building it will be
preferable to use one of the structures shown in Figures 1 and 2.
It will also be evident that a backer board could be formed
conventionally having the same shape as that presented by the
comination of boards 168,170.
All of the above structures are capable of distributing
compressive loads without causing panel separation provided of
course that a suitablQ starter strip such as that shown in
Figure 1 is used. However an alternative to this strip would be
any starter structure capabale of allowing some movement to
relieve compressive stresses built up in the wall covering as
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the building shrinks. One alternative to the starter strip is
shown in Figure 9 and the full starter board 174 is located
behind a panel 176 and attached to a vertical surface of a
building structure 178. ~rhe panel 176 is interlocked with
another panel 180 having a backer board 182 and at a Pittsburgh
lock 184. Assembly is similaL to that described with re~erence
to Figure 6 with nails 186 beiny positioned in slots with the
heads given clearance behind panel 176. The bottom of board 174
could be similar to the bottom of corresponding boards shown in
Figures 6 and 7 but is shown to provide a projec~ion 1~0 engaged
in the internal channel at the bottom of panel 176. A channel
182 adjacent the projection provides clearance for receiving a
U-shaped weatherproof cover strip 184 which is engaged after
assembly of the panel 176 if desired.
The building structure 178 shown in Figure 9 has brickwork
188 at the bottom and the board 174 overlaps this part.
The board 174 is below a board 192 which preferably has a
flat bottom surface 194 for resting both on the panel 176 and on
the board 174. Compressive forces are therefore transmitted
both to the board 174 and to the panel 176. Such an arrangement
could also be used in other embodiments.
It will be evident from the foregoing description of
various embodiments of wall coverings and starter structure that
the invention can take many forms within the scope of the
invention as defined in the claims.
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