US1796269A - Dampproofing and waterproofing walls - Google Patents

Description

March 10, 1931 J ROSE 1,796,269

DAMPPROOFING AND WATERPROOFING WALLS Filed Dec. 5, 1950 Patented Mar. 1a, 1931 JOSEPH ROSE, 01 NEW YORK, N. Y.

PATENT QFFICE DAMPPROOFIN 'G AND WATEBPiBOOFIN G WALLS Application filed December 5, 1930. Serial No. 500,341.

The present invention relates to dampproofing and waterproofing. More particularly, it relates to the dampproofing and waterproofing of the interior surfaces of ex- 5 terior walls.

, The present day practice for the construction of exterior enclosing walls may consist I Ofrfi. combination of face brick and back-up tile; common brick and back-up tile; face granite or marble backed with common brick;

walls composed entirely of common brick;

and hollow tile faced with stucco.

In what is known as skeleton wall construction the wall may be of varying thickness, but usually it is about 12" thick and has a varying degree of perviousness, permitting water and moisture to run or be driven from the outer face of the wall through the thickness thereof to the inner face, thereby Wetting and damaging the plaster which may be applied directly to the interior surface of the wall or to furring.

While walls of various construction may allow water and moisture to penetrate therethru to give a water and dampness condition above referred/t0, the latter is particularly true of walls constructed with what is known as hollow tile back-up. Figure 1 is a com- 0 posit-e portrayal of the interior face of such a Wall treated in accordance with the present invention and showing the cenientitious coating and the subsequent waterproofing coating.

5 Figures 2 and 3 are cross sections. the former showing the cementitious coating and the latter thecementitious coating and the waterproofing coating.

It is recognized that it is rather difficult D in a mechanical drawing to show all the minute details of a wall constructed with back-up tile and having mortar joints, but it is apparent'that such a wall has numerous openings comprising holes, voids and crev- 5 ices, and the mortar joints shown in the drawing have these characteristics. Many of these openings may run completely through the wall or may consist of a series of direct or staggered openings forming sub- 0 stantially free or uninterrupted passage brick backed with common brick; stone,

from the exterior surface of the wall to the interior surface. There may also he formed within the walls an interrupted passage which may allow water to flow therethru somewhat less freely than in the first case set forth.

Considering the above, it is obviousthat whenever water is driven through the'brick work or the joints of the exterior wall surface, it is not only easily carried to the interior surface in the form of dampness, but also flows through the brickwork and joints in the form of water. This is especially true when hollow tile is used in the construction of the wall. In many cases, water may accumulate between the openings of the tile or within the openings of the improperly filled joints themselves so as to build up an actual hydrostatic head, which may, of course, vary, but in some cases is as highas 6" of water. 1

It is well known that dampness penetrates through these exterior walls, and various methods have heretofore been proposed. and used to eliminate the ill effects of this dampness. These methods have consisted of applying to the interior surface, by either brush. trowel or spray, various compositions of fibre. The results obtained utilizing such methods have been more or less unsatisfac-' tory. The failureeof the prior art methods is due to anattempt having been made by means of a relatively thin coating of bitumen to withstand an actual small hydrostatic head and a real flow of water. A bitumen properly applied even in a thin coating will prevent dampness from penetrating through the film and thereby reaching and damaging the superimposed plaster, but this thin coating vbitumen or bitumen reinforced with asbestos I will not withstand actual water even under very smallheads. It has been observed that where the above set forth bituminous coatings have been applied to the interior faces of walls. the bituminous coating has been actually broken and split by the water, thereby rendering it ineflicient or ineffective.

Referring to the passage of actual water through the wall and its building up therein to form a hydrostatic head, it appeared that r the solution of the problem presented lay in arresting the activity of the water and thereby rendering it inactive, and this is accomplished by the present invention.

While it is not desired to be limited by any theory as to the mechanism of the present invention, actual observation has shown that-by utilizing a relatively thin coating of a cementitious material on the interior surface of the wall, the water coming'in contact therewith is absorbed in a blotterlike fashion by the ce'mentitious coating and distributed over a, relatively large area, the cementitious material thereby approximating a state of dampness. In other words, the hydrostatic head of water is changed from a potentially active condition .to an inactive one. The coating of cementitious material is preferably sprayed on the interior face of the wall under suitable pressure, and therefore not only functions as a coating but penetrates into openings such as cracks and crevices thereby effectively rendering inactive the hydrostatic head, and may perform other functions. Regardless of its functions, the cementitious coating accomplishes the purpose desired, and therefore, vas stated, the present invention is not limited to any theory as to the particular functions performed by the coating. Based on observation, it does act as an absorbent medium, thereby changing the actual water head to a state of inactivity approximating dampness, but even if this observation is not entirely accurate, the use of an intermediate cementitious coating is clearly herein disclosed and it cooperates, as hereinafter set forth in detail, with a subsequently applied coating of a waterproofing agent to prevent water and/or moisture from striking and spreading to the interior finished plaster surface.

The primary object of the present invention is to dampproof and/or waterproof the interior surfaces of exteriorwalls so that any water and/or moisture penetrating through from the exterior surfaces of the exterior walls to the interior surfaces thereof, and which may appear or function under a hydrostatic head, however small, is prevented from wetting and thereby damaging the interior plaster coatings applied on the interior faces of the walls.

Broadly stated, the present invention comprises dampproofing and waterproofing the interior surface of an exterior 'wall which is porous to the extent that it allows water' ings of plaster, the waterproof coating preventing the dampness from striking and spreading to the interior finished plaster surface.

While excellent results have been obtained by using a Portland cement as the cementitious material, it is obvious that this material has been selected as, being the one most suitable to work with and giving the best results. The broad disclosure being once made that it is desirable tov use a eementitious material to assist in arresting the a'ctivity'of the moisture. and/or water penetrating through the wall, it is apparent that various cementitious materials may be selected to perform this function. Eckel in his book entitled Cements, Lime and Plasters, John Wiley & Sons, Inc. 1922, on pages 9 to. 17 inclusive, classifies cementing materials; these '7 materials comprise Simple cementing materials and Complex cementing materials. Under Simple cementing materials, the first sub-groupis Hydrate cementing materials including plaster-Paris, gypsum plasters, cement plaster, and the like; the second sub-class under group 1 comprises Carbonate cementing materials or limes and magnesia derived by driving off carbon dioxide from limestone or magnesite. Under the title of Complex cementing materials, group' 1 consists of, Silicate cementing materials or hydraulic cements and included thereunder are hydraulic limes, grapp'ier cements, natu ral cements, Portland cements and puzzolan cements.

The second group under this class consists of oxychloride cementing materials.

Once given the basic invention, namely the use of a cementitious material to function in assisting to arrest the activity of the moisture and/or water, and a superimposed waterproofing coating applied thereon to bond with Qthe set cementitious material, and to form a suitable surface. for receiving and holding subsequent coatings of plaster to prevent dampness from striking and spreading to the interior finished plaster surface, it is clear that any of the cementitious materials set forth by Eckel, and their equivalents, may be broadly utilized. In some cases it will be found that some of the cements set forth by Eckel will set too quickly or too slowly. It will then be necessary to add a retarderor an accelerator. Further. in some cases, it may be necessary to modify the absorptive qualities of the cement and this may be accomplished by introducing a suitable modif ying agent which will readily suggest itself to one skilled'in the art. 'Normal Portland cement is the preferred cementitious material, but other Portland cements men- "T he preferred lubricating agent is calcium hydrate, this having in actual practice given the most satisfactory results. However, here again it is to understood that instead of using calcium hydrate other lubricating agents may be used. In some cases soaps, such as calcium stearate and ammonium stearate may be used in small quantities. Diatomaceous earth and .talc may also be used. The character of the lubricating agent is not limited.

to inorganic compounds, as organic compounds such as the soaps set forth and other organic compounds will function.

In the preferred form of the invention it is also desirable to add to the cementitious grout an agent functioning to prevent the cementitious material from setting with cracks and hair checks. Asphalt emulsions have been found suitable to function to prevent the set cement from cracking and forming hair checks. Further, the addition to the cement grout of a small quantity of an asphalt emulsion imparts to the said cement an elastic quality without waterproofing the same. It is desired to point out that the present invention is not limited to this specific agent. Various other equivalent agents may be used, such as waxes, rosins, natural and artificial resins, esther gums, stearine pitch, and the like, preferably in emulsified form.

A 'specificexample of the. cement coating is as follows :-Portland cement-80%, lime12%, asphalt emulsion-8%. This forms what is known as a dry mix, and.in order to form the grout, 7 cu. ft. -of the dry mix are added to 32 gallons of water, this giving a suitable consistency for spraying the cement coating on the interior face of the wall.

Another mixture which has been found satisfactory consists of 75% Portland cement 1 and-25%of lime. To 7 cu. ft. of this mix,

there is added 35 gallons of water containing about 10% of an asphalt emulsion, the percentage thereof being taken by volume against water.

Another mixture whlch has been found particularly satisfactory in cool wet weather, contains 50% of Portland cement, 48% of calcium hydrate, and 2% of asphalt emulsion. This forms what is known as a dry mix, and in order to form the grout, 7 cu. ft.

of the dry mix arejfatldedto 32 gallons of water.

A stable asphalt emulsion or a stabilized asphalt emulsion is preferably used, these being commercial products known to be stable in the wet state when used with cement and/or lime.

The above examples set forth the preferred grout mixtures. However, it is to be understood that the mixture may be considerably changed and still come within the spirit of the present invention, for example, should the cement have sufficient lubricating power or ability to flow easily, the lime may be omitted entirely, or under some conditions the quantity thereof present in the mixture may be substantially reduced. 011 the other hand, in some instances, depending upon the character of the cement material used, the percentage of lime may be increased. F urther, the lime may be substituted by equivalent materials as pointed out.

The function of the asphalt emulsion is to prevent the set cement from cracking and checking, and the amount thereof present in the mixture will depend upon the particular cement used. Where the cement has a little tendency to crack and check the amount of the asphalt emulsion used may be substantially reduced, or in some cases entirely eliminated. The point is here made that the grout mixture set forth represents the result of extensive experimentation to develop a preferred mixture which has been found by,

actual use to produce most satisfactory results. However, the preferred mixture merely represents the best manner of carrying out the basic invention, and further it is to be clearly understood that various departures may be made from the preferred cementitious grout material and still come within the spirit of the present invention, the basic features of which have been already set forth.

The grout of suitable consistency is placed into a suitable receptacle in operative connection with an air linedelivering or under pressure of, for example, 20 to 25 lbs. per sq. in., the pressure of the air operating on the surface of the grout mixture forcing the mixture from the receptacle into the spray gun. A portion of the air is by-passed so as to pass through the receptacle and agitate the cement grout therein so as to prevent settling of the grout-components. The grout is applied to the interior face of the wall by means of the spray gun and passes into all of the openings and crevices, and in addition, forms a coating upon the rough interior face of the wall. Not only are the relatively small holes, voids and cracks filled, but the larger holes which may not be entirely filled because of the fluid character of the grout are substantially completely lined with a grout of appreciable thickness. The thickness of i tween 1 to These figures are not to be taken by way of limitation and are, therefore, to be considered merely illustrative. It is obvious that they may be decreased or increased as circumstancesdemand.

After the grout coating is applied, usually a day is allowed to elapse before the waterproofing coating is applied. This Will allow plenty of time for the grout coating to harden and/r set. In many cases the grout coating is sufficiently hardened and/or set within hour after its application, to permit the waterproofing coating to be ap plied. Just how quickly the grout coating will harden and/or set will be determined by the character of the grout mix, the water absorptive properties of the interior wall surface to which the grout is applied, and the temperature of the wall and air.

\Vhen desired, the grout may have? retarders or accelerators added thereto so that the time of the application of the subsequent walterproofing coating may be controlled at wi l.

It is obvious that while the grout coating is preferably applied to the interior surface of the Wall by spraying, that it may be brushed on or trowelled.

After the cement coating has set a suitable waterproofing coating is applied thereto, preferably byspraying. Here again the Waterproofing coating may be applied by brushing and trowelling on the wall. It is obvious that various waterproofing coatings may be used, but from the standpoint of efii ciency and economy it is preferred to use a bituminous waterproofing coating. This bituminous waterproofing coating may bea cutback asphalt paint; a cut-back asphalt paint reinforced with asbestos fibre commercially is known as semi-mastic; a cut-back paint reinforced further with mastic into a trowel consistency and known commercially as plastic or mastic; and various types of asphalt emulsions. \Vhilethe non-emulsified bituminous coatings. more specifically cut-back asphalt, may be used, they do not function as satisfactorily as emulsions of asphalt, and particularly stabilized soap emulsions. Nor mally a soap emulsion of asphalt, soap being merely a convenient means of producing an emulsion, has the characteristics or property of drying to a glossy and tacky film, but ordinary soap emulsions of asphalt have a tendency to be unstable toward cement and lime in the wet state, and, therefore, are not the preferred waterproofing material. In view, therefore, it is desirable to use an emulsion which while drying to a tacky and glossy appearance, has at the same\\me been stabilized to an extent sufficient to o ercome the disadvantage set forth. The use of clay or bentonite as a stabilizing agent has produced eminently satisfactory results.

In general, stabilized emulsions suitable for producing the asphalt coating are prepared by feeding a suitable asphalt, for example, Mexican asphalt, having a melting point of 100 F. to 140 F. in a heat liquefied condition into a colloid mill, such for example as the Hurrell mill, and simultaneously introducing into the mill a relatively dilute The emulsion 76 the market may be used. Stabilized emulsions, such as set forth, may also be added in small quantities to the cement grout to function to prevent the same from setting with cracks and hair checks.

While as indicated, cut-back asphalts may be used, they do not function so satisfactorily, and this is believed to be due to the presence of fluxing oil-s. In other words,

experience has shown the bohd formed with I the relatively damp cementitious grout coating is not as good as that. formed when a stabilized asphalt emulsionis used; Further experience has shown that while asphalt emulsions other than those described may be used for the waterproofing coating, they'do not form as satisfactory a. surface for bonding thereto a subsequent applied coat of plaster as do the stabilized asphalt emulsions, and, therefore, in thepreferifd form of the invention the latter are used.

In cold weather the cement grout may have an anti-freezing agent added thereto to depress the freezing point thereof. Any of the numerous materials on the market may be used, including calcium chloride. The waterproofing material also may have added thereto a similar anti-freezing.material such as alcohol. v

It is clear from an inspection of Figures 1 to 3 inclusive, that the original interior face of the wall is not a true plain surface, but is rough and uneven in character due to the inherent construction of the wall. The application of the cement grouting and the subsequent waterproofing coating leave'the interior face in an uneven condition,as the grout and asphalt coatings follow substantially the contour of the original interior wall surface so as to furnish an additional and mechanical bond beyond the bond furnished by the asphalt coating itself.

The present application is a continuation in part of application Serial #385,465, filed August 12, 1929, by J oseph Rose.

It is to be understood that the present invention is not limited to dampproofing and waterproofing the interior surfaces of exterior walls. Any wall having one surface subjected to water and moisture conditions herein specified, may have the other opposing surface treated in accordance with the present invention. In other words, where one surface of the wall is subjected to water and moisture conditions, the opposing surfacemay have a cementitious coating applied thereto and then waterproofed so that the water and moisture entering the wall first strikes the cementitious coating and allows lows the latter to pass therethrough to the opholding a subsequent finishing coating, the.

posing wall surface and appear thereon and adjacent thereto in a potentially active form capable of penetrating a subsequently applied finishing wall coating unless the activity of the water and moisture is arrested, said opposing wall surface having thereon a set cementitious material adapted to arrest the activity of the water and moisture, and a coating of waterproofing material adapted to bond with said cementitious material to form a suitable surface for receiving and coating of waterproofing material preventing the dampness from striking and spreading to the finishing coating.

2. A wall of the character herein described having mortar joints, said wall being adapted to have one surface thereof subject to the attack of water and moisture and porous to the extent that it allows the latter to.pass therethrough to the opposing wall surface and appear thereon and adjacent thereto in a potentially active form capable of penetratlng a subsequently applied finishing wall coating unless the activity of the water and moisture is arrested, said opposing wall surface having thereon a set cementitious material adapted to arrest the activity of the water and moisture, and a coating of a set asphalt emulsion adapted to bond with said set cementitious material and to form a suitable surface for receiving and ho ding a subsequent finishing coating, said 5 t asphalt coating preventing dampness fro striking and spreading to said finishing coating.

A wall of the character herein described having mortar joints, said wall being adapted to have one surface thereof subject to the attack of water and moisture and porous to the extent that'it allows the latter to pass therethrough to the opposing wall surface and appear thereon and adjacent thereto in a potentially active form capable of penetrating a subsequently applied finishing wall coating unless the activity of the water and moisture is arrested. said opposing wall having thereon a set Portland cement adapted to arrest the activity of the water and moisture and a coating of waterproofing material adapted to bond with said Portland cement to form a suitablesurface for receiving amt holding a subsequent finishing coating, the coating of waterproofing material preventing the dampness from striking and spreading to the finishing coating.

4. A wall of the character herein described having mortar joints,said wall being adapted to have one surface thereof subject to the attack of water and moisture and porous to the extent that it allows'the latter to pass therethrough to the opposing wall surface and appear thereon and adjacent thereto in apotentially active form capable of penetrating a subsequently applied finishing wall coating unless the activity of the water and moisture is arrested, said opposing wall surface having thereon a set Portland cement adapted to arrest the activity of the water and moisture, and a coating of a set asphalt'emulsion adapted to bond with said set. Portland cement to form a suitable surface for receiving and holding a subsequent finishing coating, said set asphalt coating preventing dampness from striking and spreadingtosaid finishing coating.

5. The method of dampproofin g and waterproofing a wall of the charactenherein described and provided with motor joints, said wall having one surface subject to the attack of water and moisture and allowing the latter to pass therethrough and appear in a potentially active form capable of penetrating a finishing coating subsequently applied to the opposing wall surface unless the activity of the water and moisture is arrested, comprising mixing a cementitious material-with a lubricating agent adapted to lubricate the flow of the cementitious material, and an agent functioning to prevent the cementitious material from setting with cracks and hair checks, applying the mixture to said opposing wall, said mixture when set being capable of arresting the activity of the water and moisture, allowing the mixture to set, and thereafter applying a coating of a waterproofing material adapted to bond with said set cementitious mixture to form a suitable surface for receiving and holding a subsequent finishing coat, said waterproofingcoating preventing dampness from striking andspreading to said finishing coating.

6. The method of dampproofing and waterproofing a wall of the character herein described and provided with mortar oints, said wall having one surface subject to the attack of water and moisture and allowing the latter to pass therethrough and appear in a potentially active form capable of penetrating a finishing coating subsequently applied to the opposing wall surface unless the activity of the water and moisture is arrested, comprising mixing a cementitious material with a lubricating modifying agent adapted to lubricate the flow of the cement, and an agent functioning to prevent the cementitious material from setting with cracks and hair checks, applying the mixture to said opposing wall, said mixture when set being capable of assisting in arresting the activity of the moisture and water, allowing the mixture to set, and thereafter applying a coating of a stabilized asphalt emulsion adapted to bond with said set cementitious mixture and to form a.suitable surface for receiving and holding a subsequent finishing coat, said asphalt coating preventing dampness from striking and spreading to the interior finished plaster surface.

7. The process of dampproofing and waterproofing a wall of the character herein described and provided with mortar joints, said wall having one surface subject to the attack of water and moisture and allowing the latter to pass therethrough and appear in a v potentially active form capable of penetrating a finishing coating, a finishing coating subsequently applied to the opposing wall surface unless the activity of the water and moisture is arrested, comprising forming a cement grout, adding thereto calcium hydrate adapted to lubricate the flow of the cement grout, and an asphalt emulsion functioning to prevent the Portland cement from setting in cracks and hair checks, applying the mixture to said opposing wall, said mixture when set being capable of assisting in arresting the activity of the water and moisture, allowing the mixture to set, and thereafter applying a coating of a waterproofing material adapted to bond with said set cementitious mixture to form a suitable surface for receiving and holding a subsequent finishing coat, said waterproofing coating preventing dampness from striking and spreading to said finishing coating,

, 8. The method of dampproofing and waterproofing a wall of the character herein described and provided with mortar join'ts, said wall having one surface subject to the attack of water and moisture and allowing the latter to pass therethrough and appear in a potentially active form capable of penetrating a finishing coating subsequently applied to the opposing wall surface unless the activity of the water and moisture is arrested, comprising forming a cement grout, adding thereto calcium hydrate-adapted to lubricate the flow of the cement grout, and an asphalt emulsion functioning to prevent the cement from setting with cracks and .hair checks, applying the mixture to said opposing wall, said mixture when set being capable of assisting in arresting the activity of the moisture and water, allowing the mixture to set-,- and thereafter applying a coating of a stabilized asphalt emulsion adapted to bond with said set cementitious mixture and to form a suitable surface for receiving and holding a subsequent finishing coat, said asphalt coating preventing the dampness from striking and spreading to said finishing coating.

9. The method of dampproofiing and waterproofing a wall of the character-herein described and provided with mortar joints, said wall having one surface subject to the attack of water and moisture and allowing the latter to pass therethrough and appear in a potentially active form capable of penetrating a finishing coating subsequently applied to the opposing wall surface unless the activity of the water and moisture is arrested, comprising forming a grout from Portland cement, adding thereto calcium hydrate adapted to lubricate the flow of the cement grout, and an asphaltic material functioning to prevent the cement grout from setting with cracks and hair checks, applying the mixture v to said opposing wall, said mixture when set being capable of assisting in arresting the activity of the moisture and water, allowing the mixture to set, and thereafter applying a coating of a waterproofing agent adapted to bond with said set cementitious mixture and to form a suitable surface for receiving and holding a subsequent finishing coat, said asphalt coating preventing the dampness from striking and spreading to said finishing coat. I v

10. The method of dampproofing and watel-proofing a wall of the character herein de scribed and provided with mortar joints, said wall having one surface subject to the attackof water and moisture and allowing the latter to pass therethrough and appear in a potentially active form capable of penetrating a finishing coating subsequently applied to the opposing wall surface unless the activity of the water and moisture is arrested, comprising forming a grout from Portland cement, adding thereto calcium hydrate adapted to lubricate the flow of the cement grout, and an asphaltic material functioning to prevent the cement grout fromsetting with cracks and hair checks, applying the mixture to said opposing wall, said mixture when set being capable of assisting in arresting the. activity of the moisture and water, allowing the mixture to set, and thereafter applying a coating of stabilized asphalt emulsion adapted to bond with said cementitious mixture and to form a suitable surface for receiving and. holding a subsequent finishing coat, said asphaltcoating preventing the dampness from striking and spreading to said finishing coat.

11. The method of dalnpproofing and waterproofing a wall of the character herein described and provided with mortar joints, said wall having one surface thereof subject to the attack of Water and moisture and allowing the latter to pass therethrough and appear in a potentially active form capable of penetrating a finishing coating subsequently applied to the opposing wall surface unless the activity of the water and moisture is arrested, comprising applying a cementitious material to said opposing wall, said cementitious material comprising the reaction products of a mixture containing a predominating quantity of cement together with smaller quantities of a lubricating modifying agent adapted to lubricate the flow of the cementitious material as it is applied, and an agent to prevent the cementitious material from setting after applying with cracks and hair checks, allowing said cementitious mixture to set, and thereafter applying a waterproofing coating adapted to bond with said set cementitious material and to form a suitable surface for receiving and holding a subsequent finishing coat, said waterproofing coating preventing dampness from striking and spreading to said finishing coating.

12. The method of dampproofing and waterproofing a Wall of the character herein described and provided with mortar joints, said wall having one surface thereof subject to the attack of water and moisture, and allowing the latter to pass therethrough and appear in a. potentially active form capable of penetrating a finishing coating subsequently applied to the opposing wall surface unless the activity of the water and moisture is arrested, comprising applying a cementitious material to said opposing wall, said cementitious material comprising the reaction products of a mixture containing a predominating quantity of Portland cement together with smaller quantities of calcium hydrate and an asphalt emulsion, allowing the cementitious material to set, and thereafter applying a waterproofing coating adapted to bond with said cementitious material and to form a suitable surface for receiving and holding a subscquent finishing coat, said waterproofing coating preventing dampness from striking and spreading to said finishing coating.

13. An exterior wall of the character herein described having mortar joints and provided with an interior face, said exterior wall being porous to the extent that it allows water and moisture to pass therethrough and appear on and adjacent the interior face in a potentially active form capable of penetrating a plaster surface carried by said interior wall unless the activity of the water and moisture is arrested, said interior face of the wall having thereon the set reaction product of a cementitious material and a lubricating agent, the reaction product being adapted to the cementitious material is Portland cement,

the lubricating agent is calcium hydrate and the waterproofing material is an asphalt stable towards the cementitious reaction product in its wet state.

In testimony whereof he hereunto afiixes his signature.

JOSEPH ROSE.

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