Sealing collar
The present invention relates to a sealing col¬ lar for joining an underroof to a roof-penetrating construction, in particular a skylight.
Buildings are commonly provided with a roof with an outer roofing material and a subjacent weath¬ erproof underroof, such as a concrete slab or a foil of flexible material. Roof-penetrating constructions, such as skylights, chimneys etc. pose potential prob¬ lems with leakage between the construction and the underroof. Originally an artisan performed an in-situ construction of a flashing in lead, zinc or like ma¬ terials, or roofing felt. However this is very labour intensive and there is a relatively high risk of leakage, and additionally the use of roofing felt in¬ volves an increased risk of fire.
The object of the invention is to provide a widely useable sealing collar, which is easy to in- stall and provides a leak-proof sealing.
To achieve this object the sealing collar is made of a flexible and weatherproof web or sheet ma¬ terial formed to constitute a collar with an inner flange portion adapted for engagement with the roof- penetrating construction, and an outer skirt portion adapted for engagement with the underroof, said seal¬ ing collar being of substantially rectangular shape having opposing top- and bottom members and opposing side members . A further object of the invention is to provide a sealing collar useable on different sizes of roof- penetrating construction.
To achieve this further object, the sealing
collar as outlined above is characterized in that at least one pair of said opposing members are adapted for controlled variation of the length thereof be¬ tween a first predetermined length and a second pre- determined length, whereby the sealing collar may easily be fitted on any of two different sizes of roof-penetrating construction.
To facilitate easy and safe variation of the length of the members, the opposing members may be adapted for controlled variation of the length thereof by being provided with fold markings. Alter¬ natively or supplementary, the members may be pro¬ vided with lines of weakening to facilitate folding at the correct position. According to an embodiment, the opposing mem¬ bers referred to are prefabricated with an adhesive or sealant adapted to hold a folded-over portion of said opposing members, whereby sealing of the folds are guaranteed, and the need for the fitter to seal the folds after installation of the sealing collar is avoided.
The inner flange portion of the sealing collar may advantageously be provided with a circumferential ribbon, to thereby hold the inner flange portion to fit a given size of roof-penetrating construction.
Another aspect of the invention relates to a method of sealing a junction between an underroof and a roof-penetrating construction, comprising the steps of providing a sealing collar, attaching the sealing collar to the roof-penetrating construction, charac¬ terized in the further step of applying an adhesive to the contact face between the underroof and the skirt portion of the sealing collar, to securely seal
the junction between the underroof and the skirt por¬ tion to avoid any risk of leakage. The adhesive may be any conventional adhesive in this industry, such as a PU-based sealant or adhesive. According to an embodiment, the method further comprises the intermediate step of adapting the length of opposing top- and bottom members and/or op¬ posing side members to a first length or second length. Hereby a very cost-effective method is pro- vided, whereby one collar may be easily converted to fit a roof-penetrating construction of a first or a second size, with a minimum of trouble to the fitter.
To be absolutely positive that the junction be¬ tween the sealing collar and the underroof is leak- proof, the method may comprise the further step of applying a top-sealant on top of the skirt portion of the sealing collar after placing said skirt portion on the underroof.
Most common adhesives and sealants may be used, such as a bituminous product, according to an embodi¬ ment, however, the material used is a PU-based adhe¬ sive, which provides a very strong bond and further is very resistant to deterioration.
Advantageously the adhesive used is a PU-based two-component adhesive, so the adhesive will only be active when the two components are mixed, which is convenient .
Separate materials may be used for adhesive and top-sealant. However to reduce the number of differ- ent articles used, the adhesive may also be used as top-sealant.
In the following the invention will be de¬ scribed in more detail by way of example and with
reference to the somewhat schematic drawings on which:
Fig. 1 is a perspective view of a sealing col¬ lar according to the invention, Fig. 2 is a perspective view of an alternative embodiment of the sealing collar,
Fig. 3 is a perspective view of another alter¬ native embodiment of the sealing collar,
Fig. 4 is a perspective view of a part of a roof with a skylight,
Fig. 5 is a cross-sectional view of a side part of the skylight in the mounted state and fitted with the sealing collar,
Fig. 6a is an enlarged partial view of the sealing collar showing a member of the sealing collar in a folded position,
Fig. 6b is an enlarged partial view of the sealing collar showing a member of the sealing collar in a unfolded position, and Fig. 7 is a cross-sectional view of a sealing collar fitted to an isolating frame on a roof.
The sealing collar according to the invention is denoted 1 and can be seen in Fig. 1. The sealing collar 1 is made of a flexible, weatherproof material and comprises an inner flange portion 2, which may be attached to a roof-penetrating construction, such as a frame of a skylight. The sealing collar 1 is of substantially rectangular shape and comprises oppos¬ ing top and bottom members 4, 5 and opposing side members 6, 7. The sealing collar 1 further comprises an outer skirt portion 3, which may be arranged on an underroof of a building. In the embodiment illus¬ trated in Fig. 1, the sealing collar 1 is made up of
a number of separate pieces welded together, or con¬ nected in other suitable ways. By making up the seal¬ ing collar of separate elements, the amount of scrap material is reduced, as a given amount of web mate- rial can be utilized to a maximum.
An alternative embodiment of the collar 1 is seen in Fig. 2. In this embodiment the sealing collar 1 is a unitary web material arranged with an opening 21 at a central portion thereof and an inner flange portion 2, surrounding said flange portion 2. In this embodiment, the sealing collar is made of a thermo- formable web material, and the inner flange portion 2 can thus be made by thermoforming the web material to provide the inner flange portion 2. That means that the sealing collar can be produced without joints, so the risk of leakage is reduced, and further the num¬ ber of processing steps during manufacture of the collar is reduced.
Fig. 3 illustrates an alternative embodiment, in which the collar is adapted for use on roof- penetrating elements of different sizes. The shown embodiment comprises folded-over portions 10 at the top and bottom members 4, 5, so the top and bottom members 4, 5 have a length of Ll. Alternatively or supplementary the side members 6, 7 may be provided with similar folded-over portions (not shown) to pro¬ vide a sealing collar useable with roof-penetrating constructions of two different lengths. To hold the folded-over portions in place, the sealing collar may be provided with a circumferential ribbon 11. If it is needed to fold out the folded-over portions 10, to thereby increase the length of a member 4, 5, 6, 7 of the sealing collar, the ribbon 11 may be removed,
e.g. by tearing or simply by sliding the ribbon off the sealing collar. The ribbon 11 may be kept in po¬ sition by an adhesive or a few stitches.
The underroof may e.g. be a foil or web of wa- terproof material, or the underroof may be a concrete slab 12 as shown in Fig. 4 and 5. An opening 14 in the underroof is provided for a skylight 15 having a frame 16 in which a windowpane 17 is arranged. The frame of the skylight may be attached to the under- roof by any suitable means, such as brackets 18. In constructions with an underroof being a concrete slab 12, the concrete slab 12 may as shown be provided with an outer weatherproof layer 13 , such as roof felt or a coating of PU or the like. A gap 19 between the underroof and the frame 16 of the skylight 15 must be properly sealed off. As can be seen in Fig. 5, the sealing collar is arranged on the junction be¬ tween underroof and window frame 16 to seal the gap 19. The flange portion 2 of the sealing collar 1 is attached to the frame 16, such as by staples or adhe¬ sive, by a suitable clamping means arranged on the frame 16, or by a press-fit of the collar on the frame, e.g. if a somewhat elastic circumferential ribbon 11 is arranged on the flange portion 2. The skirt portion 3 of the collar is arranged on the un¬ derroof, and a sealant or glue 20 is applied at the contact face between the underroof and the skirt por¬ tion 3. The glue may for example be a pressure adhe¬ sive or a PU-based glue. To ensure an absolutely leak-proof sealing, a top-sealant 21 may as shown be applied to the upper side of the skirt portion 3, such as a liquid foil coating, covering the interface joint between underroof and skirt portion. To further
enhance the sealing quality, a strip of foil may be glued on top of the interface. A PU-based two- component sealant was tested and showed good results, both as adhesive and top-sealant, in that a very strong and leak-proof bond was achieved between the roof felt and a foil of a flexible skirt material . In fact the adhesion to the roof felt was stronger than the adhesion between the layers of the skirt mate¬ rial . The sealing collar may be manufactured from SBS (Styrene Butadiene Styrene block Polymer) . When the underroof is a concrete slab, the following apply:
Preconditions before the gluing: The concrete surface should be dry, clean, smooth and primed. This will give a very good gluing result if all above 4 items are fulfilled.
Composition of the adhesive: 1) SBS is a material which can be heated to certain degrees, so the surface will melt and it can stick onto concrete surface without any adhesive, that it also the reason why the concrete should be primed.
2) In some situations, due to the cold temperature or windy condition on the roof, so it is not convenient or safe to heat it up by flame, a chemical adhesive is allowed to be used. The correct adhesive in this case is acrylic adhesive, such as LORD 200 series.
A tested adhesive is a PU-adhesive KS-930, which is described further in the following:
Technical Data
• The product is manufactured and tested under ASTM Test Standards, and all the characteristic specifi¬ cation surpasses the international standard GB/T19250-2003. And execute the enterprise standard Q/SDKS 023-2003.
Product feature: • Solidifying type product, water can be mixed as cu¬ ring agent when application.
• 100% environmentally friendly, non-solvent content, nontoxic and odorless, applicable for drinking wa-
ter system.
• Excellent adhesion, especially for damp substrate, because water is curing agent.
100% Solids Content, resulting in a high dry film thickness per coat, normal coverage of lmm thick film is approximately lkg per sq. meter.
• Convenient to apply, the coat is self-leveling and any desired dry film thickness can be once ob¬ tained. The dry film is physically extremely strong and uniform resulting super-waterproofing. The coat will not peel off or split even if the substrate experiences big deformation such as expansion or contraction, therefore KS-930 is a prior choice when applied on complex substrate. • Excellent abrasion resistance and high elasticity, durable, wide temperature service range from minus 40 degree C to 95 degree C. Chemical aging and dire resistance.
Application Directions:
• The substrate surface must be thoroughly clean, dry and free from any contaminants or cleaning residue, oil stain or ponding water. Repair the crack if there is, structure edge angle has to be made round. The moisture content in the concrete should be less that 9% in newly finished substrates; as to old substrates apply prime for better performance.
• Remove the rust on the metal surface, apply the primer and then apply KS-930. • Stir well and make sure that the coat is even and uniform and no sediment is in the bottom, them mix
the coat well with water in the proportion of 5:1.
• The coating has to be applied over zero degrees centigrade. Some catalyst can be added if you use the coating in temperature lower than zero degree C or if you need faster curing, please contact us for details.
• The mixed coat is better used within 30 minutes.
In Fig. 6a is shown an enlarged view of a mem- ber of the sealing collar. The member is provided with a folded-over portion 10 to provide a member having a length of Ll. This length Ll may be care¬ fully predetermined to fit a length of a standard skylight frame part. The member may be provided with an amount of adhesive or sealant 9 to hold the folded-over portion 10 in the folded position. The sealing collar may be prefabricated with the adhesive or sealant 9, in which case the sealing collar advan¬ tageously may be supplied with folded-over portions 10. If the sealing collar is to be fitted on a window frame having members of a length greater than Ll, the fitter may unfold the folded-over portion 10 to pro¬ vide a length of L2 as illustrated in Fig. 6b. The sealing collar may be provided with markings 8 indi- eating the fold line, to facilitate folding by the fitter.
In Fig. 7 the sealing collar is attached to an insulating frame 22, to which a roof window may be fitted (not shown) . The flange portion 2 of the seal- ing collar 1 is attached to the insulating frame 22, such as by staples or adhesive, by a suitable clamp¬ ing means arranged on the insulating frame 22, or by
a press-fit of the collar on the frame, e.g. if a somewhat elastic circumferential ribbon 11 is ar¬ ranged on the flange portion 2. Alternatively, the flange portion 2 of the sealing collar may be at- tached to the flashing. The skirt portion 3 of the sealing collar 1 could be fixed (also by using the same adhesive) to the underroof construction, which could an under roof of the same material, a SBS un¬ derroof, or it could be a so called "auf dem sparren dammung" (normally a 10-15 cm thick insulating roof deck made of polystyrene or similar material) .
The skilled person will recognise that the pre¬ sent invention is not restricted to the embodiments described above. For example the sealing collar is useable not only with skylights, but also with other kinds of roof-penetrating constructions, such as chimneys, ventilation ducts, mountings for air- conditioning equipment, antennas etc.
Skylights are delivered in standard sizes in steps of approximately 20 cm in height and width. At present a specific sealing collar made-to-measure is provided for each size of skylight. However the cost and administration associated with the relatively large number of sealing collars is a drawback. With the sealing collar according to the invention, the sealing collar may be made to suit two or four sizes of skylights, in that the height and/or width of the sealing collar may be easily varied between the first length Ll and the second length L2. This greatly re- duces the necessary stock of different sealing col¬ lars, whereas installation is practically .as easy as with a sealing collar tailor made to one specific skylight.
The invention is not limited by the above exam¬ ples, e.g. it will be appreciated by the skilled per¬ son that instead of a unitary collar, the collar may be provided as a number of separate portions, which are connected in situ during installation.