Patent Application
20190136515
Poured concrete walls are widely used for foundations, basements, tunnels, and other underground structures. Concrete walls have many advantages, including high strength and durability. Concrete walls can be made to suit nearly any floor plan.
However, concrete is not inherently waterproof, and is not a good thermal insulator. Because backfilled earth may be in direct contact with a basement wall for decades or more, measures are typically taken to prevent seepage of water from the surrounding soil through the concrete wall and into the interior of the structure. Additional thermal insulation may also be provided below ground level, either outside the concrete wall or inside.
According to one aspect, a waterproofed concrete wall assembly comprises a vertical wall of hardened concrete, the wall having a first side and a second side. The assembly further comprises one or more boards forming a waterproof liner adjacent the first side of the wall of hardened concrete. Each of the boards comprises a polymer foam and a fibrous facer joined to the polymer foam. Some of the concrete is infused into the fibrous facer, the fibrous facer having been present at an inner surface of a form during pouring of the concrete. In some embodiments, the fibrous facer is a nonwoven facer. In some embodiments, the polymer foam is polyisocyanurate foam. In some embodiments, the polyisocyanurate foam has a density between 2.5 lb/ft3 and 25 lb/ft3. In some embodiments, the polyisocyanurate foam has a density between 4 lb/ft3 and 15 lb/ft3. In some embodiments, a plurality of boards are present, and the waterproofed concrete wall assembly further comprises tape sealing joints between the plurality of boards. In some embodiments, the tape is on an inner side of the plurality of boards, in contact with the concrete. In some embodiments, the tape is on an outer side of the plurality of boards.
According to another aspect, a method of making a waterproofed concrete wall assembly comprises constructing a form, the form having a first side and a second side. The first and second sides define a gap between the first and second sides for receiving poured concrete, and the first side is made of one or more boards comprising a polymer foam and a fibrous layer. The method further comprises pouring concrete in the gap between the first and second sides of the form, and allowing the concrete to harden, some of the concrete having infused into the fibrous layer. The method further comprises leaving the boards of the first side of the form in place adjacent the hardened concrete. In some embodiments, the method further comprises removing the second side of the form. In some embodiments, the boards comprise polyisocyanurate foam. In some embodiments, each of the boards comprises a fibrous facer on at least one side of the board. In some embodiments, the method further comprises sealing joints between the boards using a tape, a sealant, or a combination of tape and sealant. In some embodiments, the method further comprises sealing joints between the boards using a tape before the concrete is poured. In some embodiments, the joints between the boards are sealed with a tape initially having a split release liner. In some embodiments, the joints between the boards are sealed at an inside surface of the boards, adjacent the gap. In some embodiments, the joints between the boards are sealed at an outside surface of the boards. In some embodiments, the method further comprises installing form ties between the first and second form sides before pouring the concrete, to prevent expansion of the gap due to hydrostatic pressure of the poured concrete, wherein the form ties protrude from both sides of the form; removing the protruding portions of the form ties once the concrete is hardened; and sealing the points at which the form ties formerly protruded through the boards using a tape, a sealant, or a combination of tape and sealant. In some embodiments, the boards form an outside surface of the wall. In some embodiments, the second side of the form is made of one or more boards comprising a polymer foam.
Waterproofing 107 may be applied to the exterior surface of wall 103. Waterproofing may be, for example, a liquid coating applied to foundation wall 103, or may be in the form of a membrane as shown. Additional insulation 108, such as polystyrene foam, may be applied outside of waterproofing 107, for providing thermal insulation and protecting waterproofing layer 107 during backfilling of wall 103.
Various reinforcing bars and meshes may be placed in footer 101, wall 103, and floor 105.
For pouring of foundation wall 103, forms are typically assembled.
According to embodiments of the invention, waterproofing is provided for a concrete wall as part of the process of fabrication of the wall.
Any foam-containing boards may be used, but boards that may be particularly suitable include Invinsa® and GoBoard® boards available from Johns Manville of Denver, Colo., USA.
Invinsa® boards include a polyisocyanurate core and mineral-coated fiberglass-reinforced facers 407 on both sides. These boards are readily available in 4 ft.×4 ft. and 4 ft. by 8 ft. sizes, and are typically ¼ in. thick, although other sizes and thicknesses may be used if desired. The density of the polyisocyanurate core may be about 2.5 to 8 lb/ft3, and typically about 3.5 to 4.5 lb/ft3, although other densities may be used. In other embodiments, boards having facers on only one side may be used. In that case, the facer is preferably placed adjacent space 403, so that the poured concreted will directly contact the facer.
GoBoard® boards also include a polyisocyanurate core and a fiberglass facer. GoBoard boards are readily available in 3 ft. by 5 ft. and 4 ft. by 8 ft. sizes, in thicknesses ranging from ¼ in. to 2 in., although other sizes and thicknesses may be used if desired. The density of the polyisocyanurate core is typically about 10 lb/ft3, although other densities may be used.
In some embodiments, the thickness or density (or both) of the boards may be selected to meet the flexural and other requirements of the concrete forms. For example, densities of between 2.5 lb/ft3 and 25 lb/ft3 may be used, and thicknesses between 1 and 6 inches. In other embodiments, densities and thicknesses outside these ranges may be used. In addition, longer boards may be used, for example 4 ft. by 12 ft. or 4 ft. by 16 ft., to reduce the number of seams in an installation.
The polyisocyanurate core of these boards makes the boards waterproof, and the fibrous facer bonds well to concrete, because the uncured concrete can infuse into the fibrous facer to some degree. In other embodiments, different kinds of foam may be used, for example polyurethane foam. In embodiments with facers on both sides of the boards, one of the facers contacts the concrete, and the other facer is at least initially exposed to the air. This second facer may provide a second waterproofing layer, a smooth surface that is easier to clean, tape, and seal, or a more durable and abuse-resistant surface than a foam surface without a facer.
As is shown if
With form sides 401 and 402, bracing 404, any form ties 405, and any reinforcing bars or mesh (not shown) in place, concrete is poured in space 403 as shown in
In other embodiments, joints 701 and openings 702 may be sealed using an adhesive tape, for example ZIP System™ tape available from Huber Engineered Woods of Charlotte, N.C., USA, or another suitable kind of tape. A combination of a sealant and an adhesive tape may be used if desired.
Concrete wall assemblies made according to the above description may have one or more advantages over conventional concrete walls. For example, a polymer foam board may be made thicker, stronger, more flex resistant than plywood, so fewer braces may be required in the forms for the wall, reducing the labor required to make the wall. The boards also provide thermal insulation to the wall. For example, a two-inch thick Invinsa® panel may have an insulating value of about R 10, while a one-inch thick panel of GoBoard® may have an insulating value of about R 5.
Inside surface 903 of side 901 (the surface that will eventually be in contact with concrete) is lined with a waterproof membrane 904. Membrane 904 may be, for example, JM TPO FB 115™, TPO FB 135™, or TPO FB 150™ Fleece Backed Roofing Membrane available from Johns Manville, or another suitable kind of membrane. Each of the JM TPO FB products includes a thermoplastic polyolefin (TPO) membrane reinforced with a polyester fabric, and an integral polyester fleece backing. The membrane in the JM TPO FB products is nominally 0.060 or 0.080 inches thick, but other thicknesses may be used, for example thicknesses between about 1/32 inch to about 3/16 inch. In other embodiments, membrane 904 may be another kind of membrane having an exposed fibrous layer, or may be a board material as is described in more detail below. In some embodiments, membrane 904 may comprise styrene butadiene styrene (SBS) or ethylene propylene diene monomer (EPDM).
Waterproof membrane 904 may extend under form side 901 as shown by flap 905, which may lap over footer 906 to provide a continuous waterproof layer beyond the foundation. Any seams such as seam 907 should preferably be arranged so that lower course 908 of membrane material laps over upper course 909 of membrane material, when viewed from the lined side of form side 901. This ensures that upper course 909 of membrane material will overlap lower course 908 when viewed from the outside of the eventual wall, so that membrane 904 will shed water rather than providing a path of ingress toward the foundation.
Waterproof membrane material 904 may be available in rolls of material up to 10 feet wide and 100 feet long. Thus, very few seams may be required, assuming that equipment capable of carrying and handling the large rolls is available.
Clips or clamps 910 may be used to temporarily hold membrane 904 in place on form side 901, and may be removed once the concrete is poured. Intermittent lengths of tape (not shown) may be used along seam 907 to hold lower course 908 of membrane 904 in place, if desired. The weight of form side 901 holds membrane 904 against footer 906.
Concrete is then poured between form sides 901 and 1002, as described above. After the concrete has hardened, the forms are removed, and the protruding portions of any form ties 1003 are snapped off.
As in the previous embodiments, form ties 1003 may leave openings 1201 in waterproof membrane 904, as shown in
During backfilling, flap 905 may be placed against footer 906, or may form a downwardly sloping wing that carries water even further away from the wall before allowing it to seep into the ground.
The inside surface of side 1401 (the surface that will eventually be in contact with concrete) is lined with a waterproof layer in the form of waterproof boards 1403. Boards 1403 may be, for example, Invinsa® or GoBoard® boards available from Johns Manville as described above, or another suitable kind of board. Each of boards 1403 includes a fibrous facer 1404, for example a facer including a nonwoven fiberglass mat, or another kind of fibrous facer.
Concrete is then poured between form sides 1401 and 1501, as described above. After the concrete has hardened, the forms are removed, and the protruding portions of any form ties 1503 are snapped off.
As in the previous embodiments, the waterproof layer on wall assembly 1601 may include joints 1602 between the foam-containing boards 1403, and may include partial-thickness openings 1603 where form ties 1503 were broken off.
Joints 1602 and openings 1603 may be covered with a sealant 1701, as shown in
Inside surface 1803 of side 1801 (the surface that will eventually be in contact with concrete) is lined with boards 1804. Boards 1804 may be, for example Invinsa® or GoBoard® boards available from Johns Manville, or another kind of boards including a polymeric foam and at least one facer, as described above. Each of boards 1804 includes a fibrous facer on its inner side (the side that will eventually be in contact with poured concrete). Boards 1804 may be temporarily held in place using clips or clamps 1805. Boards 1804 may be pre-taped using a tape 1806, to waterproof seams between the boards. An example of tape 1806 is described in more detail below. The pre-taping may be performed on either side of boards 1804, or on both sides.
Boards 1804 may also have a facer 1807 on their outer sides (away from the concrete). In some embodiments, outer facer 1807 may extend beyond the lower edge of the board, so that a flap 1808 can be passed under form side 1801 and over footer 1809.
The remaining side of release liner 2003 can then be removed, and another board 1804 placed against form side 1801, adjoining the first board 1804 and adhering to the exposed portion of tape 1806. In the example of
Once form side 1801 and boards 1804 are in place, the second side of the form can be constructed and concrete poured as described above. Form ties may be used, or the forms may be braced sufficiently to avoid the need for form ties. If form ties are used, any penetrations of boards 1804 are preferably sealed using a sealant or tape, as described above. The resulting wall assembly may be similar to the wall assembly shown in
Embodiments of the invention may provide one or more advantages as compared with prior art methods of waterproofing a concrete wall. For example, foam boards, membranes, and sealing materials as described are weather resistant, and are not harmed by being left exposed to the elements while other construction proceeds. Because the waterproofing layer is formed integrally with the concrete wall, there is no need to wait for the concrete to cure before waterproofing can be installed. Similarly, these materials are not damaged by backfilling, and can remain in contact with backfill soil indefinitely. In addition, the waterproofing systems and methods may not require any volatile organic compounds (VOCs) as may be present in spray-applied waterproofing coatings, and no personal protective equipment may be needed during installation.
Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. Additionally, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present invention. Accordingly, the above description should not be taken as limiting the scope of the invention.
Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.
As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a process” includes a plurality of such processes and reference to “the device” includes reference to one or more devices and equivalents thereof known to those skilled in the art, and so forth.
Also, the words “comprise,” “comprising,” “include,” “including,” and “includes” when used in this specification and in the following claims are intended to specify the presence of stated features, integers, components, or steps, but they do not preclude the presence or addition of one or more other features, integers, components, steps, acts, or groups.
