BEST PRACTISE

We have two best practise guides here:

This information provided is for general guidance only. It is not intended to be definitive, and should not be used instead of professional advice.

Residential Floors

Having Concrete Laid

  • Obtain a quote from a reputable concrete placer who specialise in the particular system you require
  • Ask for examples of their work
  • Check with local Ready Mix suppliers as to reputation and quality of work

Quotation Details

Concrete Strength: Minimum 2OMPA for decorative -17.5MPA for plain finish

Concrete depth: Driveway minimum - 100mm or 4 inches
Pathway minimum - 80mm or 3 inches

Decorative System: Should be specified (i.e. Stamped concrete, Colour Cut and Grout, Exposed Aggregate, etc)

Colour: Should be specified (i.e. Cream/Charcoal, Cappuccino, Tan etc)

Pattern: Should be specified (i.e. Walkway Slate Pattern, Cut and Grout, 800mm x 800mm etc)

Area m2: The area should be shown in square metres (i.e. Length times width) e.g. 82m2

Cracks: To help alleviate the possibility of uncontrolled cracking, your concrete placer should adhere to the following guidelines:

  • The base should have fill and be compactedc
  • Concrete depth should be even over the entire job
  • Reinforcing is an option on driveways
  • Control cuts should be put into critical areas on the day of the pour
  • Shrinkage control joints should be to the relevant NZ standards

The client should note that due to expansion and contraction all concrete cracks. However, every attempt should be made to minimise potential cracking, by bolstering and / or cutting, although this will not completely guarantee the prevention of uncontrolled cracking.

Texture options: Exterior paving must have a suitable non-slip finish. Options include:

  • Texture roller finish
  • Broom finish
  • Mag, trowel finish
  • Wood float finish
  • ponge finish

Cost: Is the total cost quite clear?
Does it include GST or any PC sums?

Sealing Decorative Concrete:

  • Sealing is the most important aspect of the entire decorative concrete procedure
  • Sealer should not be applied within 7 days of pouring concrete
  • Sealer should not be applied if the temperature is less than 12°C

(Contact the nearest decorative concrete warehouse for assistance)

Download the CCANZ's guide to Residential Floor Slabs (pdf 172kb)

Commercial Floors

Scope
This document has been developed to show how specification matters might be dealt with. It utilizes, as the primary Standards for compliance, the NZ Standard NZS 3109:97 Concrete Construction (including amendments No1 and No2) in conjunction with NZS 3104:03 Specification for Concrete Production and NZS 3114 Specification of Concrete Surface Finishes.

Any specification needs to define the term “Construction Reviewer” used in clauses- 3.3.5, 5.5, 5.6.1, 7.4.1, 7.7.6, 7.7.8, 7.8.4, and 7.8.5 of NZS 3109. In this specification the Engineer to the contract has been defined as the “Construction Reviewer”.

While generic aspects of workmanship are covered in NZS 3109 the specifics relating to slab construction are not included.

For special floor applications an alternative approach is for the designer to provide outline requirements for the performance of the floor but the actual design, detailed specification, and construction is passed to the specialist flooring contractor.

Some clauses within the specification have a line in the left margin. This indicates that the information supplied within the clause is reasonably well defined in NZS 3109 and if a slimmer specification is required these clauses could be deleted.

Introduction
The specification for a concrete slab on ground project would typically be divided into the following parts:

  • Site works
  • Drainage
  • Sub-grade preparation
  • Sub-base construction
  • Concrete slab construction

The purpose of this specification is to provide typical clauses for the parts dealing either with the construction of the concrete slab, or the parts which affect this construction. It is not appropriate to include a copy of this document in a project specification, nor to refer to it as a standard specification, since each clause will have to be reviewed as to its relevance.

This guide specification does not include clauses related to general requirements such as order of works, setting out, records, inspections, etc., nor does it cover requirements for clauses of the work not directly related to concrete.

Download the entire guide specification:
Specifying Concrete Ground Floors - Final Guide Specification (pdf 495kb)