If you have pre-customised this work section using the "questions and answers" provided as part of the downloading process, it may be necessary to amend some clauses to suit the final project-specific version.
The section must still be checked and customised to suit the project being specified, by removing any other irrelevant details and adding project-specific details and selections.
For compliance of the building thermal envelope use:
The Acceptable Solutions contain a Schedule and a Calculation method & the Verification Methods contain a Modelling method for determining construction R-values required.
The acceptable method of determining the thermal resistance (R-values) of walls is contained in NZS 4214. The thermal resistance (R-value) of insulation may be verified by using AS/NZS 4859.1.
Note: NZBC H1/AS1 & VM1, for housing only, building consent applications submitted before 1 May 2023:
This section relates to Stoanz Ltd exterior Sto plastered insulation systems, applied by hand, or pump over StoTherm polystyrene panels on;
Stoanz Ltd products must be installed by an approved applicator.
Modify or extend the above description to suit the project being specified.
Refer to 4284ST STOTHERM EIFS CLADDING for 80mm and 100mm panels, when applied to a timber frame.
Include cross references to other sections where these contain related work.
Refer to the general section 1232 INTERPRETATION & DEFINITIONS for abbreviations and definitions used throughout the specification.
The following abbreviations apply specifically to this section:
EIFS | Exterior Insulation and Finish Systems |
EPS | Expanded Polystyrene |
MPNZA | Master Painters New Zealand Association |
Refer to the general section 1233 REFERENCED DOCUMENTS. The following documents are specifically referred to in this section:
NZBC B2/AS1 | Durability |
NZBC E2/AS1 | External moisture |
Structural design actions - General principles | |
AS 1366.3 | Rigid cellular plastics sheets for thermal insulation - Rigid cellular polystyrene - Moulded (RC/PS - M) |
Timber-framed buildings | |
Wet area membranes | |
Guidelines for the provision of facilities and general safety in the construction industry | |
MPNZA | Health and Safety Programme |
Health and Safety at Work Act 2015
Documents listed above and cited in the clauses that follow are part of this specification. However, this specification takes precedence in the event of it being at variance with the cited document.
Delete from the DOCUMENTS clause any document not cited. List any additional cited documents.
RELATED DOCUMENTS
Refer to the following related documents when preparing this section:
AS 1366.4 | Rigid cellular plastics sheets for thermal insulation - Rigid cellular polystyrene - Extruded (RC/PS - E) |
Guide to the painting of buildings | |
Timber and wood-based products for use in building | |
Masonry construction: Materials and workmanship | |
Concrete masonry buildings not requiring specific engineering design | |
Design of reinforced concrete masonry structures | |
BRANZ BU 633 | Removing paint coatings |
BRANZ BU 570 | Ground clearances |
Refer to the general section 1233 REFERENCED DOCUMENTS. The following documents are specifically referred to in this section:
Stoanz Ltd documents relating to work in this section are:
Sto Product Manual with specification and CAD details
Sto Technical Data Sheets
BRANZ Appraisal 478 - StoTherm Cavity System
BRANZ Appraisal 604 - StoTherm Masonry Insulation System
BRANZ | Test STO740/3 StoTherm Anchors pull through test |
BRANZ | Test DC1525 Gluecoat Adhesion test |
BRANZ | Test FH4008.1 heat release test - performance A (unrestricted) |
BRANZ | Test No DC1182 Sto Flexyl waterproofing to AS/NZS 4858 |
BRANZ StoTherm System ULS wind pressure of 2.5kPa
Materials and execution to Stoanz Ltd specification except where varied by this specification and supported by architectural detailing.
List documents relating to this part of the work, i.e. technical product/system specifications, test reports, appraisals, certification, etc. Normally they will be referred to in the text by the abbreviated title.
Copies of the above literature are available from:
Company: | Stoanz Ltd |
Web: | |
Email: | info@sto.co.nz |
Telephone: | 0-4-801 7794 |
It is important to ensure that all personnel on site have access to accurate, up to date technical information on the many products, materials and equipment used on a project. In most cases individual products are not used in isolation, but form part of a building process. Also a particular manufacturer's and/or supplier's requirements for handling, storage, preparation, installation, finishing and protection of their product can vary from what might be considered the norm. Access to technical information can help overcome this potential problem.
Use for listing all warranties relating to this section. Supplier and manufacturer warranties are those that are freely offered by the supplier or manufacturer, similarly installers and applicators. They are usually in their standard form and subject to their terms and conditions. Check the general section 1237 WARRANTIES for the date of commencement of warranties; which is normally practical completion of the contract, although not all suppliers, manufacturers, installers or applicators will agree to this. Refer to the chosen conditions of contract as it may also contain information on warranties.
Warrant this part of the work under normal environmental and use conditions against failure of materials and execution. The Sto Applicator must complete the Sto quality assurance compliance procedure form and applicator warranty. The StoThermMasonry Insulation Plaster Systems is warranted as follows:
Materials: | 15 years from date of practical completion |
Execution: | 5 years from date of practical completion |
Use only applicators registered to apply the Sto Plaster systems.
Substitutions are not permitted to any specified Sto Insulation system.
Provide protection systems as required by the manufacturer to protect fresh plaster from adverse weather conditions. Normally required curing procedures can be altered when acrylic-modified plasters (bonding agents) have been specified. Such plasters may only need to be protected from direct sun and strong, drying winds for 16 - 24 hours.
Consult the manufacturer's requirements in this clause or write another.
Refer to the general section 1270 CONSTRUCTION for details of how samples will be reviewed and how instructions to proceed will be given. Provide the following samples for review:
| Sample A | Sample B | Sample C |
Sample description: | ~ | ~ | ~ |
Sample type: | ~ | ~ | ~ |
Number: | ~ | ~ | ~ |
Location: | ~ | ~ | ~ |
Supporting documentation: | ~ | ~ | ~ |
Reviewer: | Contract administrator ~ | Contract administrator ~ | Contract administrator ~ |
Time for review: | 10 working days ~ | 10 working days ~ | 10 working days ~ |
Review criteria: | ~ | ~ | ~ |
The intention of this clause is to allow samples to be obtained that are not otherwise readily available to a reviewer.
Delete rows and columns not required or add "n/a".
Sample description: | Describe the sample, size etc. Submit one 300mm x 300mm sample of the selected finish texture and colour for review. In some instances a larger sample panel may be warranted. |
Sample type: | Portable sample for review Portable control sample Fixed sample for review Fixed control sample
Control samples define requirements for type and quality and are used for comparison purposes throughout the contract.
A "portable" sample is a sample that is easily movable, convenient for carrying. A "fixed" sample is a sample (semi) permanently placed. Expand on these terms as necessary. |
Number: | State number of samples required, e.g. a minimum of three control samples - portable allow a sample to be retained on site with the other samples retained by the contract administrator and contractor. |
Location: | Identify location of fixed samples, e.g. off site, on site, in situ |
Supporting documentation: | Describe any additional documents required to support the review. |
Reviewer:
| Modify to suit the project, add additional reviewers if required. |
Time for review: | Alter time if required.Expand to state timing in relation to when and where the sample is provided, e.g. at first site meeting. |
Review criteria: | For example: - Appearance - Texture - Colour Add any critical items. Provide clarity for work that is not dependent on the review to continue. |
Provide Sto Maintenance Schedule instructions before practical completion of the contract for issuing to the building owner.
A copy of the maintenance instructions may be required by the Building Consent Authority with the building consent application,
Refer to the requirements of the Health and Safety at Work Act 2015 and WorkSafe: Guidelines for the provision of facilities and general safety in the construction industry.
If the elimination or isolation of potential hazards and risks is not possible then minimise hazards and risks in this work on site by using the proper equipment and techniques as required in the MPNZA Health and Safety Programme. Supply protective clothing and equipment. Inform employees and others on site of the hazards and risks, and put into place procedures for dealing with emergencies. Obtain from Stoanz Ltd the material safety data sheets for each product. Keep sheets on site and comply with the required safety procedures.
Provide a producer statement from the approved Sto applicator in the form as required by the Building Consent Authority.
Use the number of anchors appropriate for the wind zone (R) and topographical classification (T) of this site and building height; as required by NZS 3604 and the wind loads on various wall areas as given by AS/NZS 1170. Modify this clause depending on whether NZS 3604 or AS/NZS 1170 is being used as a design basis for the project. Refer to Stoanz Ltd technical information for StoTherm Anchor centres required for the building wind zone.
Allow to inspect the whole of the work at each stage. Determine a programme for inspections including notification when each part and stage of the work is ready for inspection prior to the work commencing.
If requested permit representatives of Stoanz Ltd to inspect the work in progress and to take samples of their products from site. Refer to Sto product manual.
The level of inspection will depend on the nature of the project and will range from full for large or complex projects, through to intermittent for straightforward work, to occasional for initially establishing the standards of execution. Refer to AS/NZS 2311 Appendix C, Inspection and Testing, for more background.
The work covered by this part of the specification has been designed and constructed to meet the NZBC durability requirement for 15 years with a serviceability life in excess of 30 years. Refer to the following:
BRANZ Appraisal 604 - StoTherm Masonry Insulation System
Accept responsibility for the structural and weather-tight performance of the exterior render application.
Refer to the following BRANZ Tests:
WARNING
Mutually exclusive clauses follow. Check your chosen cladding system and select accordingly.
Rigid cellular polystyrene made from fire-retardant virgin beads to AS1366.3 class S.
40, 60, 80 and 100mm thick EPS S grade polystyrene panels.
Delete panel or sheet thickness not required.
Use only StoTherm panels on masonry construction.
StoTherm 60, 80 and 100mm masonry anchors with 60mm washers counter sunk into the StoTherm panel using a ST fixing tool and plugged with a ST Cap to prevent thermal bridging fixing spots.
For fixing over timber or masonry. Note 40mm fixings are face fixed and fixing spots can occur due to thermal bridging.
Cement based mineral adhesive mortar for adhering panels in place on masonry construction before fixing with StoTherm Anchors
For fixing over masonry. DELETE if not required.
Mineral basecoat plaster in a bag. The material contains mineral aggregates water retention agents, adhesive compounds, fibre and other additives to form a solid, basecoat plaster.
Alkali-resistant, 165g/m² fibreglass mesh in 50 metre rolls, or 360g/m² Sto Panzer Mesh for areas requiring extra impact resistance.
Delineate on the drawings or delete Panzer mesh if not required.
Reinforcement plaster in a pail with a calibration grain. A white non cement flexible meshing plaster containing organic fillers and fibres bound in a polymer dispersion to form a malleable crack resistant intermediate plaster with excellent adhesion qualities.
Six different coloured finishing renders (as selected) in a pail. Containing organic aggregates and fibres bound in a polymer dispersion with enhancement agents and colouring pigments. Refer to SELECTIONS for texture and colour.
Stolit K 1, 1.5, 2, 3mm aggregate renders and Stolit MP / MP Natural are sponge renders.
Matt coloured pure acrylate facade paint; natural looking matt, hard, durable, coating with excellent resistance to weathering. Refer to SELECTIONS for colour.
Select for coating Stolit K renders.
Clear, invisible Silane sealer for ease of cleaning and added protection against staining of coloured sponge finishes (Note: were a clear coating is required contact Stoanz Ltd).
Select for sealing Stolit MP or MP Natural renders.
Non compressible anchor board for supporting penetrations through the cladding.
Head and any other required flashings made from powder coated aluminium, stainless steel or uPVC for both recessed and faced fixed timber, aluminium and uPVC joinery to NZBC E2/AS1, 4.0 Flashings.
Sto uPVC Flashings are to be used for weatherproofing the exterior plaster at joinery openings, transitions, junctions, terminations and for forming corners and drip edges.
Waterproof membrane conforming to AS/NZS 4858 for waterproofing balustrades, parapet tops, horizontal ledges and foundation splash zones.
Use on EPS cladding as a waterproof membrane and for balustrades, sloping horizontal ledges and waterproofing masonry foundations as per Sto details.
Sto 8mm - 12mm uPVC control joints, for vertical or horizontal control joints.
An expanding polyurethane foam impregnated inseal tape for weatherproofing joints.
For filling any voids in the panel and sheet joints.
BRANZ appraised modified MS sealant.
For fixing fitments that have a total face load of less than 8 kg.
Fitments such as downpipe brackets, lighting and security fittings.
Keep Sto bagged plaster products dry in transit. Take delivery of Sto plaster products in good condition. Reject all damaged materials and immediately notify supplier in writing.
Deliver all materials in original unopened packaging with labels intact. Provide dry storage on site, stack carefully, protect from mechanical damage. Keep bagged render dry and off concrete surfaces.
Carry out plastering to Stoanz Ltd specification under conditions which will not adversely affect the finished work.
Refer to Sto product manual.
Before application of plaster, apply masking film and tape to all joinery, pipes, roofs and all areas likely to be marked by the plaster. Use drop cloths and ground covers to keep the working areas clean. Clean off droppings onto finished work immediately.
Ensure the main contractor and the sub trades are aware of their responsibilities relating to the required provision of weather tight details at all junctions, penetrations, overlays and transitions including any rebates required (see www.sto.co.nz for details).
Do not commence work until required openings and apertures have been detailed, pipes, and fixtures have been fixed, flashings, waterproofing and other preparation are complete. Do not commence the Sto system until substrate is of the required standard by the Stoanz Ltd approved applicator. All defects in substrate must be rectified prior to the commencement of application of plaster to StoTherm Masonry Insulation System.
Before commencing work confirm the layout of expansion joints and other visual detailing of the finished work.
Choose one of the following systems and DELETE the other.
Install 40, 60, 80 or 100mm StoTherm panels adhered in a brick pattern to the masonry substrate with Gluecoat Mortar applied in a 75mm perimeter band with three 150mm spots through the centre. StoTherm 80 and 100mm panels are mechanically fixed by drilling holes at each panel corner junction and at the 600mm centre on the joint line with one additional hole in the middle of each panel. The position is marked and drilled using a rotary impact hammer with an 8mm masonry bit. The StoTherm anchors are placed in the holes with the 60mm washer covering the adjacent panel edges and countersunk using the ST fixing tool attached to an electric drill with the ST tool plate stopping flush to ensure correct panel compression and security. StoTherm 40mm and 60mm are mechanically fixed using StoTherm impact anchors as previously detailed and hammered home to sit 2mm below the surface. Stotherm 60mm panels can be countersunk using a Sto Router to countersink the hole before placing the StoTherm impact anchors.
All countersunk anchors are then plugged with the supplied ST insulation caps to fit flush and eliminate thermal bridging. Panels require a PVC cap when edges are exposed or for installation against dissimilar materials, junctions and transitions. Panel joints shall be straight and true. Concrete joinery rebates are waterproofed with Sto Flexyl installed as per the Sto CAD details. Any sheet gaps to be Sto adhesive foam fused.
Select panel size 40mm, 60mm, 80mm or 100mm thick StoTherm polystyrene panels.
All joinery openings in the masonry construction require 25mm masonry rebates as per standard concrete block details. To prepared surfaces apply two brush coats of correctly mixed Sto Flexyl to the interior rebate including the rebate step. To the exterior rebate from the rebate step out over the StoTherm panel apply Sto Flexyl meshed waterproofing.
DELETE if timber frame construction.
Comply with the Stoanz Ltd flashing details. All penetrations such as waste pipes, electrical wiring in uPVC conduits and metal plumbing piping install with a minimum 5° downward slope, through the Sto plaster system, to be sealed using a double application of MS sealant.
Where shown on the drawings and to Stoanz Ltd requirements insert Sto flexible uPVC V control joints. Reflect exposed control joints through final coatings from substrate, terminating the plaster reinforcing mesh each side of the Sto uPVC control joint.
StoTherm Masonry Insulation System requires that any control joints formed in the substrate are mirrored through. Refer to Stoanz Ltd CAD drawings.
Modify if CAD drawings are in project drawings.
Fix EPS shapes used to create detailing and or at inter storey joints after the sheets have been base mesh coated, using Gluecoat mortar applied to the shape prior to placing over the prepared sheets. Temporary fixings may be used while the adhesive cures. All plant on shapes to be pre-meshed or receive a StoArmat mesh coat and be sealed especially along the top junction with a bead of MS sealant before the finish plastering commences.
All junctions between joinery / adjacent surfaces / differing materials sections and the plaster mesh coat, and around penetrations shall be sealed with MS sealant.
Use on all plaster systems
On horizontal plastered surfaces a minimum slope of 10° is required. On parapets and balustrades tops a polystyrene shape sloped at a minimum 10° is normally used as a capping. Apply Sto Flexyl / Meshed waterproofing to a minimum thickness of 1.5mm followed by StoArmat mesh coat and Sto plaster finishing render. Sto Flexyl must be extended 75mm up and down adjacent vertical plaster surfaces and cover cap joints.
Refer to SELECTIONS for type and colour.
The choice of a light colour will help by reducing thermal movement - LRV 25% minimum.
To clean dry cladding apply one straightening coat of Multiscreed basecoat plaster by hawk and trowel or pump at an approximate thickness 4 - 6mm using guides and corners as required. Rule or screed the surface to achieve a level plane ensuring a minimum thickness of 5mm is achieved.
Before commencing on the walls, all the joinery reveals are to have pre meshed corner angle install embedded in a StoArmat plaster coat
Apply one even coat of StoArmat reinforcement plaster at approximate thickness 1.5 - 2mm. While plaster is still wet lightly embed Sto mesh ensuring adjacent drops of mesh are overlapped by a minimum of 75mm. Float surface to ensure mesh is lightly embedded into the StoArmat reinforcement coat. Allow to dry and apply one further coat of StoArmat reinforcement plaster at approximately 1mm thick to leave the plane even surface free of voids or deviations. Ensure all joinery openings are meshed in StoArmat. Once dry remove any slight ridging with a Sto rasp.
Apply selected Stolit K or MP coloured finishing render applied with a stainless steel trowel gauging to the thickness of the aggregate size and finished with a plastic float to the requisite pattern. Apply Stolit MP or MP Natural in two coats and finish with a float and judicial use of a damp sponge
Thickness and styles of renders varies between Stolit K- 1 / 1.5 / 2 / 3mm & Stolit MP/MP Natural - sponge.
Refer to SELECTIONS for preferred finish.
Apply one coat of StoColor Maxicryl matt facade paint tinted to the selected colour on Stolit K render, or Protectosil SC easy clean sealer on MP finishes.
Colour must have a minimum light reflective value (LRV) of 25%. Refer to SELECTIONS for preferred paint finish. If Stolit K is not the selected finish colour two coats may be required.
Stolit MP, MP Natural are sealed for added protection.
Remove debris, unused materials and elements from the site relating to plaster system application. Replace damaged, cracked or marked elements. Leave the whole of this work to the required standard.
A final inspection by project assessor of the entire finished plaster system to take place immediately after completion of the application work and any defects or subsequent damage made good immediately.
Substitutions are not permitted to the following, unless stated otherwise.
Location: | ~ |
Substrate: | StoTherm ~mm panel |
Base coat: | Multisceed basecoat, 4 - 6mm thick, to straighten walls |
Mesh coat: | StoArmat meshed reinforcement plaster |
Finishing render: | Stolit~ |
Paint: | ~ |
Sealer: | ~ |
Paint coats: | One |
Colour: | ~ |
Options:
Substrate: | 40mm, 60mm, 80mm or 100mm thick StoTherm polystyrene panels |
Finishing render: | Select render type, size and colour: |
| Stolit K is a coloured finish render select- 1 / 1.5 / 2 / 3mm (aggregate ) |
| Stolit MP is fine plain coloured - MP Natural is sand specked sponge render |
Paint or Sealer: | Select Sto Color Maxicryl for Stolit K or Protectosil SC sealer for Stolit MP |
Colour: | Refer to Sto. Colour must have a minimum light reflective value (LRV) of 25% |