September 15 -  21, 2019: Issue 421


Installing Posts For Decks And Verandahs With Heavier Loads + Installing Membranes For Tiled Decks

As part of our DIY Deck Refurbishment: Turning Wood Into Open Tiled Spaces all the posts previously installed needed to be checked and some replaced to carry the heavier load of tiles. In Australia there are regulations to cover what size post you need to install to carry a load to meet ASA and Safety requirements.

The New South Wales Guide to Standards and Tolerances 2017, produced by New South Wales Fair Trading, gives you all the information you need to ensure your project is compliant.

Posts in contact with the ground should be either preservative treated pine or In-ground Durability Class 1 hardwood, with any sapwood
preservative treated. Refer to ‘Construction Timbers in Queensland’ for suitability

Preservative treatment for posts in the ground and framing on the ground, shall be to hazard level H5. Preservative treatment for framing more than 150 mm above ground should be H3.

The weight bearing load or size of the post you will need is based on the square metres in total and what you may place on the deck, other than tiles - for example, some pots for plants can be quite heavy and when you fill them with soil and then a plant, which requires watering, heavier still. Some outdoor barbecue furniture is so solid and built to last that it too can have quite a heavy load it too will place on the posts holding up your deck or verandah. 

Before installing posts

When designing and building timber decks where timber is less than 400 mm from or on the ground, consideration must be given to the following to ensure good long term performance:
• adequate ventilation 
• surface drainage 
• correct timber species selection
• access for future maintenance and termite control.

Only termite resistant timbers should be used for decks. Protection of the dwelling to which the deck adjoins must also be considered. This could be achieved by leaving an appropriate gap for inspection. It may be necessary to provide a removable panel, to inspect physical management systems (e.g. metal caps) or to retreat where a chemical perimeter treatment to Australian Standard AS 3660.1 has been used on the dwelling.

Decks (and posts) must be:
• constructed from naturally termite-resistant timbers, in accordance with Appendix C  in AS 39660.1, or
• constructed from preservative-treated timber in accordance to Appendix D of AS 3660.1; or
• have a termite barrier to protect the primary building elements installed in accordance  with AS 3660.1.

Primary building elements include framing members, floor (decking boards), stairways and ramps, i.e. elements that take part of the building load. Where installation of a termite barrier according to AS 3660.1 is chosen as the method to provide protection, AS 3660.1 requires attachments to buildings, such as decks, to be separated at least 25 mm from the building. Where this can’t be achieved, the termite barrier must be extended to include the deck.

Termite protection can be achieved by placing all posts that support the deck framing on galvanised metal stirrups that have at least 75 mm clearance above the finished ground level:

The metal stirrups installed on our posts - also treated prior to installing (makes it easier to do last coat of paint)

All bolts, screws, nails, brackets, framing anchors and other hardware should be hot dipped galvanised or stainless steel. Electroplated
fasteners are not suitable due to early breakdown of the plating. 

Footings for supporting posts are usually designed in two ways. The most common method is concrete footings with galvanised stirrups embedded or fixed in the footings to support the posts. An alternative method is to support the deck post by embedding the post directly into the concrete footing. When this method is used, care is required to use no-fines concrete, have adequate concrete under the post and slope the top of concrete footing away from the post.

The design of footings is outlined in AS 2870 or AS 1684. Usually, the soil classification and expected loads on the deck are required to be known. Decks designed to AS 2870 and AS 1684 are for decks used for housing with average loads and ground conditions. If these conditions are not met (e.g. the deck needs to support a spa or the deck is to be tiled), the design needs to be considered by a structural engineer.

As shown above, posts are usually connected to concrete footings via a stirrup. They are generally preservative-treated softwood (H3 hazard level) or natural above-ground durability Class 1 or 2 timber species.

The span tables within AS 1684 have the required timber sizes for posts (that table is available here). These are dependent on the deck area, roof area (if any), post height and stress grade of the timber selected. Common cross-sectional sizes for posts vary, but usually start at 88 mm and upwards. Minimum sizes for posts are also governed by the distance between the ground and the underside of the bearers. The maximum height of a deck above the ground for a given post dimension is 15 times the face width of the post.

Deck posts need to be braced and AS 1684 has various bracing methods. These methods are either cross bracing between posts or as a cantilever timber stump.

Deck and balcony maintenance checklist
If your deck just needs some pre-Summer maintenance, this checklist compiled by the New South Wales Fair Trading as a quick guide to help you inspect and maintain your deck or balcony.

Be safe. If there appears to be anything suspicious about the stability of a deck or balcony, avoid the area, and get the structure inspected by an expert. An expert can help to diagnose a problem and provide advice on fixing the problem.

All decks and balconies:
  • Check that the structure is properly fixed to the main building. Use a pushing and pulling action on the main supporting beams or joist to check for signs of movement.
  • Think about the number of people and objects on a deck or balcony. Large loads placed on a deck regularly or on special occasions may exceed the load that the deck or balcony was designed to hold.
  • Think about the safety of children and visitors. Do not let people climb on the balustrades or handrails of decks. They may not be designed to withstand that load and may lead to falls from elevated heights, resulting in serious injury or death.
Stairs, handrails and balustrades:
  • Check for signs of rot, corrosion, looseness or instability.
  • Stairs, handrails and balustrades should be securely fastened at all points. Pay particular attention to balustrades that are fixed to the balcony’s top surface and not fixed directly to the main supporting structure.
  • Look for signs of sagging or loss of tightness where wire balustrading has been used.
Timber balconies and decks:
  • Check the timber for signs of decay, rot or insect attack. For example, is the timber spongy when probed with a sharp object?
  • Look for signs of bending, warping, sagging and splitting. Pay close attention to beams that span long distances without any supporting posts and columns.
  • Check to see if the timber needs a reapplication of stains, oils or paints, remembering different timbers may need different treatment.
  • Check bearers and joists are adequately supported.
  • Check all connections for signs of deterioration, such as beam to post connections, and for any loose or rusting fixings.
  • Check for loose decking boards or flooring.
Concrete balconies and decks:
  • Look out for signs of deflection or leaning.
  • Check for the presence of spalling, where chunks of concrete flake off or crack.
  • Examine the underside and edge of the balcony for rust stains or exposed steel reinforcing.

Installing A Membrane For A Tiled Deck

Waterproof decks and balconies substrate Waterproof decks and balconies are defective if they are not constructed in accordance with the BCA and AS 4654.2. Fore this stage of your converting a timber deck to a tiled one it is best to employ the services of a Licenced Tradesperson - a Tiler. The products used can be toxic and difficult to work with if not experience in their application - leave this one to those who can not only do it best but also provide the accepted Certification.

Waterproof decks and balconies are defective if the waterproofing system is not installed in accordance with the manufacturer’s installation requirements.

Decks and balcony freeboard outside windows and doors: Waterproof decks and balconies are defective if they do not have a drainage system sufficient to withstand wind-driven water surging from the deck or balcony that complies with the Building Code of Australia and AS 4654.2.

Ponding on waterproof decks and balconies Waterproof decks and balconies are defective if water ponds (with the exception of residual water remaining due to surface tension) or does not drain to the outer edge or a stormwater inlet.

Decks and balconies that are required to be waterproofed are defective if they are not provided with adequate drainage and provision for overflow.

For those who like to see this part of the project come together - and for their own reference when getting a membrane installed at home, some photos: -

There are new products being developed all the time which provide a better result. When waterproofing our installed cement sheets we applied a layer of Primex Primer prior to the Tiler installing the membrane. Davco PrimeX is an advanced surface primer designed to increase the bond strength of tile adhesives and waterproofing membranes. This product is suitable for use over steel trowel concrete and compressed fibre cement sheeting. Use prior to the application of waterproofing membranes and tile adhesives to reduce pin holing, ensure an even drying time and increase bond strengths.

This can be put over the sheets using a paint roller - it's worth purchasing a pole like that used for rolling ceilings.

Prior to installing the membrane the Tiler will check the edges to ensure they're square and as sharp as they should be and will provide the correct drainage and where, after membrane installation, water may pool and adjust that surface tension. 

Although ensuring the edge of the cement sheeting is sharp and square may be something a DIYer can do themselves, most Tilers are particular about the end result, and the required Certifications, and will do this themselves.

When preparing to install a membrane the Tiler will take into account what the weather may be about to do over the days after the installation. Most membrane manufacturers specify minimum cure times. These average from 24 to 72 hours. As an average membrane cure time requirement is to allow an adequate drying time of 48 hours at 25C and 50% relative humidity - longer if you live in a cool damp pocket of Pittwater. 

As our yard has 20 x spotted gums and a fair amount of all-year-round shade as a result, a slope that funnels water from the back of Whale Beach down to Careel Bay, a good three days drying time after installation was required. Not only that, due to being a block of land that will remain damp long after the hill across the valley has dried out, two layers membranes were installed to protect the framing and cement sheeting supporting the to be installed tiles.

Installing a membrane looks like this:

Adhesive and leveller applied in areas Tiler identifies as potential pooling runs

The tiles have been ordered and are being delivered as this step in the process is published. 
Prior to the Tiler commencing those works we're renewing and installing new Balustrades - and that runs next!

A protective barrier to prevent accidental falls is usually comprised of handrails, infill and posts that support it. A balustrade may be made from many materials including timber, metal, glass etc.
A beam supported by a wall, piers or posts that in turn supports joists or other framing.
A covering of a frame that provides protection from the weather and is usually not load-bearing.
A horizontal framing member that is supported on or by bearers, ledgers or other structural members that in turn supports floor or ceiling linings such as decking boards.
A member that is attached to a house frame. It is designed to support a deck and transfers the weight of the deck to the house foundation.
A structural component, such as a beam or column, or part of an assembled structural component.

Products And Tools To Help You Get It Done 

from the Johnson Brothers Mitre 10 Spring into Action catalogue - available online HERE - on sale until September 22nd, 2019

RotaCota Perfect Applicator Range - Buy 3 Perfect™ Painting Products and Get a FREE Canister of Perfect™ Painting Treats.* • Large range of sizes & styles to suit any paint project. See in store for full range *Promotion available from 9:00am Tuesday 27 August, 2019 until 5.00pm on Tuesday 31 December, 2019 or While Stocks Last. Participating stores only.

Ox 900mm Pro Saw Horse:  2 for $150.00

Makita 18V Li-Ion Circular Saw Skin* :$199.00   
                 • 165mm. • Bevel cuts up to 50° *Batteries & charger sold separately.                  

Makita 125mm Random Orbital Sander: $199.00
Trigger with variable speed control by dial. 

Spear & Jackson Box Level Pack: $49.00
• Includes 600mm & 1200mm aluminium spirit level & 230mm magnetic torpedo level.

Stanley 57 Pce Screwdriver Set: $25.00
• Standard & Phillips™ head screwdrivers. • Multi-bit screwdriver & assorted bits. • 1/4" drive sockets (Metric/AF).

Stanley Fatmax 8m Tape Measure: $27.90
• 8m x 32mm or 8m/26' x 32mm.

Makita 18V Li-Ion 2Pce Combo: $649.00
FREE Blower & 5.0Ah Battery Via Redemption*

Includes Mobile Brushless Hammer Driver Drill, Mobile Brushless Impact Driver, 2 x 5.0Ah batteries, charger & carry case. *See for full terms & conditions.

Johnson Brothers Mitre 10 Trade Centre at Mona Vale - everything you need under one roof.

Green Life Garden Centre at Johnson Brothers Mona Vale

Johnson Brothers Mitre 10 New Store
73 Bassett Street
Mona Vale - Online Store: Jbhmv.Com.Au

Products advice is available from the trained friendly staff at Narrabeen, Mona Vale and Avalon Johnson Brothers Mitre 10. 

Click on logo to visit Johnson Brothers Mitre 10 website

Johnson Bros Mitre 10 - Avalon            (02) 9918 3315

Johnson Bros Mitre 10 - Mona Vale     (02) 9999 3340

JBH Timber & Building Supplies          (02) 9999 0333

JBH Fencing & Landscape Supplies    (02) 9970 6333 Online store:

All information and tips in this publication are of a general nature only and neither Johnson Brothers Mitre 10 or Pittwater Online News does not warrant the accuracy or completeness of the information and tips in this publication. This publication is not intended to be a substitute for expert advice. Johnson Brothers Mitre 10 advises you to always consult an experienced and qualified person when undertaking jobs of this kind (including consulting a qualified tradesperson such as an electrician or plumber where relevant expert services are required). 

You should also consider any safety precautions that may be necessary when undertaking the work described in this publication (including wearing any necessary safety equipment such as safety glasses, goggles or ear protectors or hard hats). The information and tips in this publication are provided on the basis that Johnson Brothers Mitre 10 and Pittwater Online News excludes all liability for any loss or damage which is suffered or incurred (including, but not limited to, indirect and consequential loss or damage and whether or not such loss or damage could have been foreseen) for any personal injury or damage to property whatsoever resulting from the use of the information and tips in this publication. 

Pittwater Online News and Johnson Brothers Mitre 10 also advises there may be laws, regulations or by-laws with which you must comply when undertaking the work described in this publication. You should obtain all necessary permissions and permits from council and/or any other relevant statutory body or authority before carrying out any work. Major projects published in this publication always list these and/orlinks to where you may research what your own project requires to meet regulations.

Previous DIY Pages:

Decking Timbers  Caring For Your Deck Decking Finishes  Privacy Screens I Privacy Screens II  Privacy Screening Hardwoods  Autumn Paths and Lawns  Insulation Batts Plasterboard  Ventilation - Edmond's Ecofan Blackboards for Children and Home Spring Lawn Care  Shade Sails & Watering  Basic DIY Tools DIY Tools - Power Drills Recycle Your Trampoline into An Air Bed  How to Build Your Own Backyard Cricket Pitch Christmas Lights Displays around House and Garden Summer Mildew - Refresh, Renew How to Fix Things That Drip and Bump in the Night Time To Plant Winter Vegetables in  a Raised Garden Beds Layout Organsing Your Tool Shed  Make Your Own Weathervane Installing A Garden Watering System  Decking Oils  How To Make Garden Compost  How To Winter proof Your Lawn  How to create Shabby Chic effect on Timber Furniture How to Build Your Own Raised Garden Bed  Growing Your Own Winter Vegies  Winter Heating Guide  Prepare Your Yard For Winter Eradicating Noxious Weeds From Your Yard How to Fix Furniture Finishes Part I  How to Repair Scratches, Dings, and Dents of Furniture Surfaces - Part II Winter Draughts Fix  Classic Wooden Tool Carrier Spring Garden Checklist Part I  Install Your Own Skylight  Retaining Walls for Saving Soil and New Spring Garden Beds  Summer Salad Garden  Native Plant Garden for A Fairy Arbour Renewing Short Flight of Exterior Stairs Deck Maintenance DIY Summer Tasks You Can Do In Time to Get to the Beach  Garden Ponds for Attracting Birdlife, Dragonflies and for the Soothing Sounds of Water  Salt Air: Maintenance and Protection Creating an Outdoor Dining Arbour, Gazebo or Patio - Part I Creating an Outdor Dining Arbour, Gazebo or Patio Part II  Autumn Garden Tasks  Autumn DIY Jobs: Waterproof Your Home Checklist  Dealing With Dampness Inside the Home  Fixing Your Fence  Repairing and Replacing Damaged Decking boards  DIY Toy Box and Snow Globes: School Holidays Fun - Winter 2015  DIY Wooden Toy Cars and Perfect Painted Flowerpots: School Holiday Fun - Winter 2015  Shoring Up an Under House Earth Bank – Installing a Basic Retaining Wall  DIY One Shelf Sideboard  Early Spring 2015 Garden Care Salad Garden For Children  Keeping Your Garden and Home Cool in Hot Weather  Classic Beach Garden and Camping Chairs 3 Portable Versions Anyone Can Make DIY Outdoor Furniture Mark I: Park Benches for Your Garden Make Your Own Scooter or Skateboard: Summer 2016 Fun  How to Install a Solid Core Door and Door Furniture  Summer Garden Jobs: Pruning A Hedge  How to Make A Swing Chair - With A Frame for Garden Setting  Garden Jobs for March to Make A Beautiful and Healthy Spring  Keeping Outdoor Nooks Warm During Cooler Months  Children’s Step Stool with Storage  Stop Winter Rain Lawn Loss and Soil Erosion on Slopes  DIY Garden Shed: Part 1 of 4 - Base  DIY Garden Shed: Part 2 - Framing Walls  DIY Garden Shed: Part 2b - Gable Roof Framing  Garden Shed Part 3: Roof Installation  DIY Garden Shed: Weather- boards - Door And Window Installation And Paint Finish DIY Coffee Table With Chessboard Inlay  Spring Gardening: Feeding Your Soil And Plants - What Works For Each Plant  DIY Sandstone Flagging Parking Area - Platform  DIY Pre-Summer Checklist For A Safe Home   Summer Spruce Up: Interior Paint Tips and Three easy steps to rejuvenate your timber deck The Perfect BBQ Garden Setting DIY Water Wise Garden   DIY Side Gates  DIY Storm Preparation And Home Protection  One To Two Day DIY Weekend Spruce Ups  Vegepods For Autumn Planting + Easy To Make Lego Table Or Student Desk That Can Be Dismantled + Johnson Brothers Mitre 10 Online Store   Johnson Brothers Mitre 10 Great New Mona Vale Store: Still In Bassett Street - number 73  Johnson Brothers Mitre 10 New Mona Vale Store: The Greenlife Garden Centre  Go Outside And Play: Creating Garden Spaces To Connect Children With Nature DIY Plasterboard Repair DIY Dolls House Or Garage Or Boatshed  DIY Child's Waggon - or use as a large planter mover DIY Bathroom Refresh: Zing For Spring  Tips for Growing a Native Garden FireCrunch, Australian Developed Fire-proof, Sustainable, Durable and Reliable Building Board Now Available at Johnson Bros. at Mona Vale and Narrabeen School Holidays DIY Ideas for Children: Little Vegetables Garden, Swing, Windchimes Bushfire Season Preparation 2017: Home and Outdoor Areas  Johnson Brothers Mitre 10 Trade Centre at Mona Vale + Issue No 1 of Mitre 10’s inSITE Magazine for Tradies and Handymen  Preparing Al Fresco Areas for Christmas Get-Togethers and Summer Visitors  Summer De-bug; Mosquitoes, flies, cockroaches and ants - how to keep the outdoors insects where they belong DIY Summer Projects: Install A Fountain Or Water Feature  Late Summer and Early Autumn Projects: A Shed For All Storage Solutions + Garden Tasks + Keeping Our Waterways Clean   Autumn Plantings for Winter Harvests   2018   Paintback Collection Event: Johnson Bros Mitre 10 Mona Vale Saturday, April 7  Reducing Ticks in Your Garden: Garden care, Plants that Repel, What to Wear Outdoors Attracting Insectivore Birds to Your Garden: DIY Natural Tick Control  Mother's Day 2018: DIY Rose Garden Winter Mould & Mildew Inside Your home: How to Keep Air and Surfaces Healthier DIY Traditional Rocking Horse  Johnson Brothers Trade Day 2018 DIY Mushrooms and Vege Kits: School Holidays Fun Winter 2018 for Curious Kids  Woodworking Projects for Beginners: School Holidays Fun Winter 2018 - Simple Storage Box + Wood Tool Box Spring Garden Prep: Soil Care  Spring into Spring + JBH August 2018 Trifecta  DIY Backyard Doggie Paradise  Garden Care for Heavy Rain Days + Non-Toxic Snail and Slug Debug Ideas  Garden Design and Plant Management to Minimise Tick Attacks and Infestations - insights from an essay by Bill Conroy BSc. (Agr) (Syd) + a Tribute to Wilfred Lawrence Conroy CBE by Keith Jackson, PNG and others  Make Your Own BBQ Kitchen Garden: Gifts That Grow Past That Giving Day  Christmas Lights 2018: Light Up the Night  How to Keep Your House Cool During a Heatwave Without Using an Air-Conditioner Mid-Summer Garden Care  2018 Winners Of National Hardware Store Of The Year - Johnson Bros Mitre 10 Mona Vale! + End Of Summer Garden To Do List  DIY Fruits of Your Garden: Growing Figs  Fruits Of Your Garden: Growing Passionfruit - Autumn Is Also The Time To Plant Strawberries For Spring  How To Water Your Plants When Away On Holidays + Some April 2019 School Holidays Fun For Outdoors; A Skateboard Swing Or Indoors; Grow Or Make Pot Plant People Dealing With Autumn Dampness Inside The Home + Mums Day Gifts For 2019 Winter Heating Guide + Get Ready For Winter Specials  Keeping Your Garden Dewful During Times Of Water Restrictions and Drought  Installing Leaf Stopper Gutter Guard + Trade Day 2019  JBH Mitre 10 Trade Day Guests 2019  An Artfull Garden - for Winter School Holidays 2019 DIY Deck Refurbishment: Turning Wood Into Open Tiled Spaces - Groundworks  Father's Day Wish List 2019 + How to Re-stain your Deck timbers and posts for Summer


John and Bob Johnson - The Johnson Brothers Profile  John William Alfred Johnson - The Eulogies for those who could not attend Mass

Australia's Prime Minister Visits Mackellar - Informal Afternoon Tea with Hon. Malcolm Turnbull October 2016

JBH Win Awards August 2018 Trifecta - 2018 Free Trade Day supporters, Mitre 10 Heritage Advert features JBH Mona Vale Store, Hardware Australia’s 2018 NSW Hardware Store of the Year over 2500sqm.

Front Page Issue 294: 2018 Winners Of National Hardware Store Of The Year - Johnson Bros Mitre 10 Mona Vale !!!