[0001] The present invention concerns a corner flashing for covering corners on building
elements that are led through a surface impacted by water, as e.g. a chimney or attic
on a roof.
[0002] For corner flashings, e.g. at attics or chimneys, it is common to use workable plates
of lead. Use of this material is unfavourable due to environmental considerations,
but experience in i.a. Denmark has shown that other materials and installation methods
have not yet been convincing for corresponding use, and therefore are not used widely
either. Since the use of lead for flashings becomes illegal in Denmark as from 1
st January 2003, the lack of substitute materials is particularly problematical. The
mounting of lead plates also require specially trained manpower for assembling the
lead plates by soldering. This is a time-consuming process which is encumbered at
low temperatures and by bad weather.
[0003] It is the purpose of the invention to indicate a flashing or covering for corners
on roofs, e.g. chimneys or attics, substituting lead, so that it is without contamination
of the surroundings, the flashing or covering being durable, simple and rapid in mounting,
and which is relatively cheaper than present methods as the working time in connection
with establishing a flashing is considerably reduced.
[0004] This purpose is achieved with a corner flashing for covering corners of building
elements that are led through a surface impacted by water, where the flashing or covering
includes a water channel and a front covering part at an angle thereto, and where
the front covering part includes a deformable section.
[0005] The advantage of the flashing provided by the invention is i.a. that it may be prefabricated.
Making the flashing thus becomes independent of weather and wind, and the prefabricated
flashing may be examined for tightness before leaving the place of production. The
flashing can be mounted at the site of application without using specially qualified
manpower as it only has to be fastened to the corner on the building element. As opposed
to that, existing lead flashings are to be soldered at the site of application, requiring
specially trained manpower and possibly impeded by weather and wind.
[0006] The quality of the flashing in general and the soldered joints in particular is furthermore
difficult to check at the existing lead flashings as they are individually made by
individual craftsmen.
[0007] The water channel may be made with a fixed, limited length. After mounting the flashing,
the water channel may be extended by mounting a loose water channel with a suitable
length and with the same profile as the water channel of the flashing. The loose water
channel is to be mounted with a certain overlap over the water channel of the flashing
and is effected after the flashing has been mounted. The loose water channel is fastened
with a suitable means. This may be e.g. soldering, bonding, tubular riveting with
a suitable, interposed joint filler, or with "hafter". The water impacted surface
will often have a non-planar surface. This will e.g. be the case when the flashing
is to be performed on a roof with tiles, concrete or asbestos cement. In order to
minimise the risk that water is blown up under the flashing, the front piece comprises
a deformable part. The deformable part may be deformed during mounting so that it
nearly fits tightly to the non-planar roof covering.
[0008] It will also be simple to connect two flashings with a loose front piece. A building
element may be covered with two corner flashings, after which a loose front piece,
which can fill out the interspace between the flashings, can be fastened. A certain
overlap should be provided for joint to be sufficiently tight. The fastening may e.g.
be performed with soldering, bonding or tubular riveting with a suitable joint filler
lying behind.
[0009] In a further embodiment of the invention, the deformable section of the front covering
part includes a pleated surface. A pleated surface is easier to deform than a corresponding
plane material, and the use of a pleated surface enables deforming the section for
the roof covering manually or with light hand tools, as e.g. a hammer, so that it
fits down in the bulging/wavy roof tiles or roof plates.
[0010] In a further embodiment of the invention, the front covering part includes a plane
section. This will often be an interspace between the building element and the roof
structure. Since the front covering part thus does not need to be adapted to the roof
covering at this section, it is advantageous to let a part of the front covering part
be plane, and thus avoid the costs of pleating the entire front covering part, as
well as the front covering part thereby becomes more rigid.
[0011] In a further embodiment of the invention, the front covering part includes an upright
part. The covered building element often has an approximately upright front face.
This face will also be impacted by water. Therefore, it is advantageous to provide
the front covering part with an upright part that may lead the water from the vertical
front face of the building element and further down onto the front covering part.
The upright part may be made as a real loose edge with a fold back for insertion into
the building element, or maybe covered with a common loose edge after mounting.
[0012] In a further embodiment of the invention, the water channel includes at least one
upright side, where at least one of the upright sides of the water channel includes
an offset. The water channel can conduct larger amounts of water down to the front
covering part when the water channel has upright sides. One upright side may possibly
be fastened to the building element in order to collect water thereof. This side may
be designed as a real loose edge with fold back for insertion in the building element,
or for being covered with a common loose edge after mounting. The offset on at least
one of the upright sides provides possibility of easily adapting one and the same
type of prefabricated flashing for different roof slopes. It has appeared that by
using this embodiment of the invention, it is possible to readily adapt the same type
of prefabricated flashing for roof slopes between 30 and 65 degrees by using manual
power.
[0013] In a further embodiment of the invention, the water channel includes a fold back.
A fold back of the water channel will minimise the risk of water being pressed in
under the flashing in the interspace between the water channel and a retrofitted,
loose water channel.
[0014] In a further embodiment of the invention, the angle between the water channel and
the front covering part is largely a right angle. Many building elements have perpendicular
corners, why it will be particularly suitable to make the flashing with a right-angled
corner.
[0015] In a further embodiment of the invention, the flashing is made of zinc. Zinc is already
used for flashings on water impacted surfaces, and experience shows that the material
is weather-resistant. Besides, it has the advantage that it will mellow and appears
very much like lead. Using zinc will therefore also be possible on constructions that
for aesthetic reasons, e.g. due to listing, are to appear as flashings made of lead.
Furthermore, by using zinc for covering zinc attics, a nicer total appearance is achieved.
[0016] Moreover, together with copper, zinc has the advantage that by annealing it attains
stretching properties that enable the zinc or copper to be deformed and thereby shaped.
In connection with this invention, the shaping or adaptation may occur by mounting
the corner, e.g. around a chimney or an attic. The pleated part may be formed so that
it fits to the shape of the roof material, e.g. waved tiles. Usual zinc, which is
not annealed, will crack by this working, but due to the annealing the material will
stretch and thereby not crack.
[0017] Zinc rolls are already commercially available, where part of the width is pleated,
and which may easily be deformed manually. This type of zinc is marketed by Rheinzink.
[0018] The flashing may be made in one piece, or made by bending and soldering together
pleated zinc flashing, e.g. of the Rheinzink type with a prefabricated water channel.
[0019] In addition to zinc, copper is a preferred material too. For attics covered with
copper, it is not possible to use zinc, as the two materials are situated in the reactivity
series so that the zinc-copper connection will cause galvanic corrosion and thereby
destroy the zinc.
[0020] Correspondingly, aluminium may be used under proper consideration of the reactivity
series.
[0021] The invention will be described in more detail in the following with reference to
the drawing, where
- Fig. 1
- shows an embodiment of the invention in perspective view, and
- Fig. 2
- shows two specimens of an embodiment assembled with a front piece.
[0022] On Fig. 1 is shown an embodiment of the invention in perspective view. The water
channel 1 of the flashing and a front covering part 2 are shown here at a mutual angle
9 which is largely a right angle. The water channel 1 includes two upright sides 6,
7. The purpose of the sides is to ensure that the water in the water channel 1 is
guided upon the front covering part 2. One side 6 is here lower than the other side
7. This is due to required space for tiles overlapping the roof gutter so that only
a few centimetres of the water channel remains visible. The other side 7 may be provided
with a bend so that it can function as loose edge and be inserted in a groove in the
covered building element. Alternatively, the other side 7 may be covered with a loose
edge. The other side 7 is here provided with a bend 14 intended for enclosing the
corner on the building element and to minimise water penetration. The water channel
1 is made with an increase in width against the front covering part 2. It is necessary
to ensure sufficient run-off possibilities for the water if a possible deformation
for the sake of the underlying roof covering causes an elevation of the front covering
part centrally of the water channel. The water channel 1 is provided with a fold back
10 intended for preventing water from being pressed up between the water channel 1
and a retrofitted loose water channel.
[0023] The offset 8 is created for enabling adapting the same type of flashing to different
roof slopes. Thus it has appeared to be quite unproblematic to use the same type of
flashing for roof slopes between 30 and 65 degrees. Larger intervals may be attained
by a greater offset.
[0024] In the shown example, the front covering part 2 consists of a plane section 3 and
a deformable, pleated section 4. The deformable section 4 may be produced of the same
material as the plane section. In that case, it is only the pleating that causes the
deformable section 4 to be deformable. In order to divert water from the frontal plane
surface of the building element, the front covering part is further provided with
an upright part 5. This part may easily be bent in a suitable angle so that it fits
in to the building element. The upright part may furthermore include a bend so that
it can be used as loose edge. Alternatively, the upright part 5 is provided with a
turn-in 15 and covered with a loose edge. The turn-in 15 minimises the risk of water
being pressed in between a retrofitted loose edge and the upright part 5.
[0025] On the Figure, the angle 9 between the water channel 1 and the front covering part
2 is a right angle. A right-angled corner will fit a lot of building elements that
are to be covered. The flashing may of course be made with angles adapted to the angles
of corners of other building elements.
[0026] Fig. 2 shows how two mutually mirrored flashings may be used with a common front
piece. After mounting the two coverings 11, 12, the front piece may 13 may mounted
between the flashings 11, 12 with a certain overlap. The joints between the flashings
11, 12 and the front piece 13 may be done with soldering, bonding or with tubular
rivets with a suitable joint filler lying behind.
[0027] The same prefabricated flashing or covering may thus be used for covering building
elements with very different widths.
1. Corner flashing for covering corners of building elements that are led through a surface
impacted by water, where the flashing or covering includes a water channel (1) and
a front covering part (2) at an angle (9) thereto, and where the front covering part
(2) includes a deformable section (4).
2. Corner flashing according to claim 1, wherein the deformable section (4) of the front
covering part (2) includes a pleated surface.
3. Corner flashing according to claim 1 or 2, where the front covering part (2) includes
a plane section (3).
4. Corner flashing according to one or more of the claims 1 to 3, where the front covering
part (2) includes an upright part (5).
5. Corner flashing according to one or more of claims 1 to 4, where the water channel
(1) includes at least one upright side (6, 7), and where at least one of the upright
sides of the water channel includes an offset (8).
6. Corner flashing according to one or more of claims 1 to 5, where the water channel
(1) includes a fold back (10).
7. Corner flashing according to one or more of claims 1 to 6, where the angle (9) is
largely a right angle.
8. Corner flashing according to one or more of claims 1 to 7, where the flashing is made
of zinc.
9. Use of a corner flashing according to one or more of claims 1 to 8 for covering building
elements in the group consisting of attics, chimneys and building elements that are
led through a surface impacted by water.