SEALIT MULTI PURPOSE

UNIVERSITY TEST E. 514 74
RATED "E" - EXCELLENT

WATER PERMEANCE OF 90MM CONCRETE BLOCK MASONRY TREATED WITH "SEALIT"

Report No. MRC-53.  Dr. R.G. Bathgate, September 1987.

DURAC Ltd Deakin University Victoria, Australia 3217 Telephone (052) 471212

SUMMARY

A single leaf hollow concrete block (90 x 90 x 390mm) test wall was given the recommended 'Sealit' treatment of 50/50 percent 'Sealit'/water, 24 hours air drying, 1 00 percent 'Sealit' and 24 hours air drying. It was subjected to a standard water permeance test with the equivalent of 140mm per hour rain and 100.6 km/h wind for three days. It was rated in the highest class for resistance to water permeance, E (for excellent), with no leakage, no visible water on back of wall, 8 hours to first appearance of dampness, and damp patches less than three percent of total area after three days.

In contrast, the same wall, tested in the same conditions before sealing, was rated in the second lowest resistance class P (for permeable) with no leakage, dampness appearing in only 1.8 hours, visible water on back of wall after only 2.05 hours and the dampness extending over 80 percent of the total area after only one day.

CONTENTS

1. TEST SPECIFICATION AND PROCEDURES

             1.1  Equipment

             1.2  Test wall and sealing treatment

             1.3  Test procedures and observation

2.  INTERPRETATION OF RESULTS

TABLE 1

FIGURES

1.    TEST SPECIFICATION AND PROCEDURES

The specification used in Australia is "Standard Method of Test for Water Permeance of Masonry, E514-74, prescribed by Committee E-8 on Permeance of Building Constructions and published in 1974 by the American Society for Testing and Materials.

This method covers a procedure for determining the resistance to leakage of unit masonry subjected to wind driven rain.

1.1  EQUIPMENT

Refer to E514-74 for a complete description of the rain and wind simulation equipment but a brief description follows.  A test chamber,3ft. (914mm)widex4ft. (1219mm)high x6in. (152mm)deep in fixed to one side of a test wall and sealed around the periphery.  The chamber contains a spray bar, near the top, which receives water from a centrifugal pump so that "rain" lcan be applied at a specified rate.  An air blower is also attached to the chamber to apply "wind pressure" at a specified value.

1.2  TEST WALL AND SEALING TREATMENT

A test wall was built, approximately 1200 mm wide x 1800 mm high, using hollow concrete blocks 90 x 90 x 390mm and 1:1:6 mortar.  The wall was cured in the laboratory for 28 days (the minimum) before testing commenced.

After the initial test the wall was given the manufacturer's recommended treatment of the sealer "Sealit" viz: 1 coat of 50%'Sealit'water mix with 24 hours air drying time followed by A 100% coat Sealit and a further 24 hours drying time.

1.3  TEST PROCEDURES AND OBSERVATIONS

The full procedures as specified in E514-74 was followed.  A preliminary test exposure of rain and wind was applied io the wall for one day.  The back (inside) of the wall was allowed to dry (about four days) and, within 24 hours, was painted with a thin coating of whitewash to facilitate observation of moisture penetration.  A further drying period of 24 hours was allowed after the whitewash had appeared to be dry.

Rain and wind were applied again for three days.  During this time photographs were taken of the back of the wall at appropriate intervals to allow the specified observations recorded in table 1.

The test chamber was removed, the wall allowed to dry out (about seven days), and the 'Sealit' treatment applied.  The test chamber was replaced, sealed and rain and wind applied again for three days.  Photographs were taken and the specified observation's recorded in table 1.

The photographs which provided the results are shown in figures 1 to 1 1.

2.    INTERPRETATION OF RESULTS

E514-74 defines five classes of resistance to water permeance of test walls, E, G, F, P and L in order of least to greatest permenance (i.e. E is most waterproof and L is least waterproof.  The test wall before it was sealed was rated class P- "Water visible on back of wall in three hours or less (actually 2.05 h) and rate of leakage less than 5 litre / h (actually nil) at the end of one day".

After sealing, the test wall was rated as E-"No water visible on back of wall at the end of one day.  Not more than 25 percent (actually less than 3 percent) of wall area damp at the end of three days.  No leaks (flow of water form flashing at bottom of back of wall greater than 0.05 litre/h) through wall at the end of one day".

TABLE1- OBSERVATION OF WATER PERMEANCE

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