In the opinion of ABSAC, the Tech-Dry Water Repellent Block wall system will prevent water penetration in walls by wind driven rain and rising damp Provided that:
1 .The Tech-Dry Water Repellent Blocks are laid using Tech
Dry Mortar Additive mixed and applied according to
TASCO Bricks Blocks and Pavers, 'Specification
TechDry Mortar' (January 1997).
Note: Tech-Dry Water Repellent Blocks, Tech-Dry Water Repellent Retaining Wall Specification
Water Repellent Retaining Wall Specification Mortar
Additive and instructions are available from
distributors throughout Australia.
2.The wall is constructed in accordance with Australian Standard, AS 3700-1988'SAA Masonry Code' (MDT 1 January 1989, MDT 2 March 1991, Amdt 3 April 1992, Amdt 4 July 1994).
3.Control and articulation joints are designed to prevent water penetration.
4.Weep holes are included in the bottom course.
Note: The performance of the system is reliant on the wall being crack free.
BUILDING CODE of AUSTRALIA
In the opinion of ABSAC, the system described in this Technical Opinion and installed under the conditions listed herein will satisfy the relevant requirements of F1.4 'Weather proofing of roofs and walls' of the Building Code of Australia (BCA) (2nd Edition, 1990 including Amendments 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10).
In the opinion of ABSAC, the system described in this Technical Opinion and installed under the conditions listed in this Technical Opinion will satisfy the performance requirements of Clause FP1.4 (Volume 1 Class 2 to Class 9 buildings) and Clause P2.2.2 (Volume 2 - Class 1 and Class 10 buildings Housing Provisions) of the Building Code of Australia (including Amendments 1 and 2). Notes: (i) The inclusion of this clause with reference to the Building Code of Australia (BCA) is aimed at assisting those involved in the building permit/process to relate the Appraisal to their relevant regulations. (ii) Any changes made to the BCA will be reviewed during the term of validity of this Technical Opinion and, where necessary, any amendment required will be published in the annual ABSAC Directory of publications.
TECHNICAL OPINION RELATED INFORMATION
VALIDITY OF THE OPINION
This Technical Opinion applies only to the use of the Tech-Dry Repellent Blocks and Tech-Dry Mortar Additive as described herein.
This Technical Opinion will be withdrawn or amended if ABSAC considers that a change in design or manufacturing quality renders the basis of appraisal invalid, or if reported field experience convinces ABSAC of unsatisfactory quality or performance.
Term of Validity: This Technical Opinion will lapse three years after the date of issue unless revalidation has been requested and granted (see back page).
Standards Australia, AS 3700-1988'SAA Masonry Code' (Amdt 1 January 1989, Amdt 2 March 199 1, Amdt 3 April 1992, Amdt 4 July 1994) TASCO Bricks Blocks and Pavers, 'Specification Tech-Dry Mortar' (January 1997)
APPROVED OPINION EXTRACT
The'Tech-Dry Water Repellent Block' wall system as manufactured and marketed by TASCO Bricks Pavers and Blocks, Burnie, Tasmania is suitable to prevent water penetration in walls by wind driven rain and rising damp when the conditions listed in ABSAC Technical Opinion 231 are fulfilled.
The following description is based on information supplied by the applicant.
TASCO Tech-Dry Water Repellent Block is a concrete block which has a waterproofing material blended throughout the entire block. A mortar additive is supplied to create water repellant mortar joints to establish a totally waterproof wall. The blocks are available in a series of sizes. They
are designated 10.01 for the 100 mm series, 15.01 for the 150 mm series, 20.01 for the 200 mm series and 30.01 for the 300 mm series. Each series includes half bricks, and corner bricks
Any masonry is constructed in accordance with
Australian Standard, AS 3700'SAA Masonry Code'. The
Tech-Dryad mortar is mixed at the rate of two (2) litres of
additive to 20 litres of water. Cement ratio must be 1 to
3 using a 'fatty brickies sand'. Neither plasticisers nor
lime should be added to the mix.
TASCO Tech-Dry Water Repellent Block is a concrete block
which has a waterproofing material blended throughout
the entire block. A mortar additive is supplied to create
waterproof mortar joints to establish a totally waterproof
In the opinion of ABSAC, the TechDry Water Repellent
Block wall system will give a waterproof life in excess of
25 years provided there are no cracks developed within
BASIS OF APPRAISAL
ABSAC has assessed the following aspects in
undertaking this appraisal:
(a) The applicant's installation instructions.
(b) The physical properties of the material.
(c) The ability of the system to cope with movements.
(d) The ability of the system to prevent moisture ingress.
The following documents and inspections were used in
carrying out the appraisal.
1.TASCO Tech-Dry, 26 Bass Highway, Burnie,
Tasmania 7320. Material safety Data Sheet'Block
Emulsion' (15 April 1996).
TASCO Bricks, Blocks and Pavers, 'Specification
Tech-Dry Mortar' (January 1997):
This provides mixing ratio of the additive to water
and liquid to cement. It provides estimating data for
the mortar mix and size of block.
TASCO Tech-Dry, 26 Bass Highway, Burnie,
Tasmania 7320 (24 October 1997):
This letter provides details of in-house quality
assurance procedures. Quality assurance
procedures and testing used by the manufacturer of
the mortar additive and the supplier of the sand
material used in the blocks.
1.Victoria University of Technology, Ballarat Road,
Footscray, Victoria. 'Salt erosion resistance of
concrete blocks' Reference BPSU/120 (6 July
This report is on a comparison of untreated concrete
blocks and concrete blocks containing Tech-dry
block emulsion. The blocks containing the emulsion
showed significant less weight loss and were still
intact after 15 cycles of testing.
Victoria University of Technology, Ballarat Road, Footscray, Victoria. 'Water absorption of concrete blocks' Reference BPSU/128 (15 August 1995): This report is on concrete blocks containing Techdry block emulsion. A capillary water absorption over a 24 hour period of treated blocks compared to untreated blocks showed a reduction of 90% water absorption.
3.Victoria University of Technology, Ballarat Road,
Footscray, Victoria. 'Water absorption of mortar
containing Tasco/Tech-Dry Mortar Additive'
Reference BPSU/134 (18 October 1995):
This report is on concrete blocks containing Tech-
dry block emulsion. A capillary water absorption over
a 24 hour period of treated blocks compared to
untreated blocks showed a reduction of 90% water
4.Brick & Mortar Research Laboratory (NATA
registered), Kinnoull Grove, Syndal, Victoria
3150. 'Breaking and compressive strength of
concrete paving slabs' Test Certificate No.
Z5087B (24 April 1996):
Testing was performed on coloured concrete paving
slabs containing emulsion. The slabs were supplied
CSIRO, Building Construction and Engineering. Confidential BC E Doc 971177 (M) 'Report on Tech-Dryad Water Repellent Block Wall System to ASTM E514-90 'Standard Test Method for Water Penetration and Leakage Through Masonry' (September 1997): This is a qualitative test. The wall showed minimal water penetration at two mortar joints which would be approximately equal to an area of 0.04% of the wall after 4 hours. (It should be noted that the mortar was hand mixed). Even though the test time is specified as 4 hours, the test was allowed to run for 72 hours. (it was noted that the slight signs of dampness had evaporated within 24 hours of commencement of the test.)
1 .Tech-Dry Building Protection Systems Pty Ltd,
Melbourne, Australia. 'Water Repellent
Admixtures for Concrete' Kebao Ren, Anthony
Caselli, Douglas Kagi (Not Dated):
This paper discusses the effects on treated concrete
due to the addition of a silicone admixture. The
paper also includes discussion of the above tests
relating to water absorption, salt erosion and