Decks, Balconys, and Safety

Last weekend this attractive looking balcony collapsed killing 2 people and injuring 17

For the full story check out the following link: The Age

With the party season now underway its worth thinking about whether your balcony/deck is up to the situation.


You may think that you are just inviting a few friends round……. but the average adult weighs over 75Kilos,

So if you are having 20 guests around for a party their combined weight will be over 1.5 tonne, that’s heavier than my car.

Get them to group together for a photo and all that weight is in a small area.

If they start dancing there are dynamic forces as well.

What can be done?

Well if you are planning a deck in the future make sure that it’s properly designed and constructed.

There is no room for “That looks strong enough….No worries”.

If you have an existing deck then check that its up to scratch:

  • No rot in the timbers
  • No corrosion
  • No loose fittings
  • Make sure the wall bolts holding the structure against the walls are secure.
  • Handrails are secure
  • Maximum spacing between balustrade rails should be 100mm

Before a party its a good idea to stop too many people going on a balcony, so put a couple of tables out there,

A table loaded with food might seem heavy but it will still be lighter than 4 or 5 adults.

Corrosion Protection – Galvanizing

Mild steel is used a lot in construction as it is a, relatively inexpensive, strong structural material.

It does however have an issue in that it can be susceptible to corrosion in certain locations such as:

  • Buried in the ground. (for example retaining walls)
  • Subject to regular wetting. (roofing sheets)
  • High humidity locations. ( for example above heated pools and spas)
  • Salty atmosphere. (such as near the sea)

One way of protecting the steel is galvanising, which is the application of a layer of zinc over the steel.

Here are the galvanising options you may be offered:

Hot Dip Galvanising

With this process the prepared section of steel is dipped into a bath of molten zinc.

When the section is removed a fairly thick layer of zinc encases the steel providing a durable corrosion resistant layer.

The appearance is of a dull grey material with a crystalline look.

Electro Galvanising

This is an electoplating process where a layer of zinc is bonded to the steel.

The item is dipped in a saline zinc solution and an electrical current is passed through the solution into the steel.

Although it results in a thinner layer of zinc, than hot dipping, the bond between the zinc and the steel is stronger so the effectiveness is comparable.

Cold Galvanising

Cold galvanising is the application of a zinc rich paint to the steel.

Although not as effective as true galvanising it is a better solution than paint alone.

One of the main uses is to provide complete zinc cover after site cutting, drilling, or welding of galvanised products.


Welding of galvanised steel is hazardous as the welding process releases toxic fumes. . . not a DIY exercise!


Creating a Traditional Timber Frame Home Plan

Guest post by Tyler Linden

Traditional timber frame home plans can be a wonderful way to build while being environmentally conscious, because they’re efficient, long-lasting, and strong.

Many timber frame houses standing today in Europe date back to the 12th century, and some date back to the 17th century in North America.

This is a testament to the longevity of timber frame homes and their solidity throughout the ages – what this really does, is help reduce waste throughout time.

However, even a solid timber frame left neglected and exposed to the elements over centuries can start to deteriorate.

If you find a century-old timber frame home (or even an old barn) here is how to restore it to make a new home.

First, you need to assess if you have a structural problem or a superficial one.

If the structure is a little rotten or if the bones of your home have been shredded by termites, you’ll need a timber frame home plan, whether it’s a full or partial, to help you renovate or build a new, while being respectful of the environment.

Superficial Damage

If the problems with your home are largely superficial—for instance, if the siding is ripped up or the doors are eaten through—than your solution is fairly simple.

Peel off the layers of the house to get it down to the bones.

Then salvage the wood that you can, replace the wood that you can’t, and reconstruct the parts that are damaged with new, clean wood and siding.

Structural Damage

If your problems are structural—if, for instance, your house has been eaten through by termites—then your solution will need to be more complex.

First, identify any wood that can be salvaged, because you’ll be reducing your construction-based foot print.

New structural timber frame pieces are expensive for two reasons.

  • First, they are large: a small structural piece is 150mm by 150mm, while larger timbers can be 300mm x 400mm with lengths of up to 9m.
  • Second, timber frame homes aren’t kept together by nails. They are put together using wooden joinery crafted to exacting standards by skilled craftsman.

When deciding what to keep and what to discard, it is recommended that you first hire a qualified firm or engineer to assess what can be repaired or what needs replacing.

Although it’s better to err on the side of caution, you don’t necessarily have to scrap every piece of wood that has damage.

Structural epoxy can sometimes be used to rebuild pockets of rotten wood in the timber, as long as these pockets aren’t too large. . . . they should be, at a maximum, as large as a softball.

You can also use steel straps to strengthen joins, rather than ordering a new piece of wood. , , ,not ideal, but can be an option.

When it comes to replacing the timber, you need a qualified supplier.

Many companies can replace damaged timber in old homes by using new structural-graded timbers that are shaped and distressed to match the timeless look of the timbers in the rest of house.

Carefully Plan Your Method Of Attack.

One element that’s overlooked when beginning a project like this is the importance of having a well-organized site.

Mark out a large, flat site next to your house to work.

If there’s not one, you may even consider clearing one in order to be more efficient.

Number every piece of wood, so your pieces don’t get confused with others. . . Timber frame homes make this easy, because even in the 19th century they tended to be built along similar lines; so you can easily mark, for instance, all the right front corner posts.

Numbering every piece will make your life a lot easier when it comes time to replace damaged wood with new pieces.

Before you start removing timbers it’s important to make the building stable.

Your house is already damaged, and you’ll be ripping out siding and even structural pieces, so you need to take precautions to ensure that the entire thing doesn’t collapse on top of you.

Cribbing is an excellent idea, but as with everything else, you need to have an organized timber frame house plan.

You need to lay out a plan pre-emptively for your cribbing so that it supports the areas that need support, without impeding your ability to maneuver.

Building a stack of cribbing right in front of the chimney that needs to be ripped out, for instance, may not be the best idea.

Finally, you’ll need to deconstruct the structure, ripping off the old and worn wood to replace it.

What that involves will depend on the scope of your problem.

Preserving Your Timber Frame Home

The last step is to strengthen the wood so that weathering is less damaging in the future.

SANSIN water-based sealers, for instance, are an environmentally friendly option that can toughen the outside of the wood.

Textured finishes can also strengthen the wood while giving your timber frame home a rustic appearance.


A timber frame house plan isn’t easy, but it can be much better than losing your treasured 17th or 18th century timber home to damage.

If you decide to tackle this project yourself, these tips should get you started.

If you’d like to hire someone to help, there are many excellent firms out there that have plans that are adaptable to any type of needed renovations.

Regardless of whether you hire help or renovate your house yourself, you’ll end up with a structure that’s beautiful, historic, pays tribute to the environment, and as strong as anything built today.

Tyler Linden is a blogger for Hamill Creek. He has a background of structural engineering and he loves to spend most of his time playing in the great outdoors. You can find him on Google+ and on Twitter.

Construction – Holes In Timber Frames

The house frame has all been completed, and inspected . . . . and then some idiot plumber drills holes in the frame like this!

Right through the bottom plate, and the top plate, of both storeys of the house!

Holes are often drilled in:

  • Studs*
  • Plates*
  • Beams /Joists

* see Basic Timber Frame  for an explanation of these terms.

If it’s not the plumber drilling through the frame it might be the electrician or air conditioning installer.

So what is allowable?

Holes in Studs, and Plates, of Wall Frames

  • Only on wide face of Stud.
  • Maximum size of hole 25mm dia
  • Must be in centre of Stud.
  • No closer than 3 x width of stud from any trench cut into stud.

Holes in Solid Beams

Horizontal holes no more than 25mm dia

  • Maximum of 3 in a 1.8m length of span.
  • Each hole must be at least equivalent to the beam depth from the adjacent hole.

Horizontal holes no more than 50mm dia

  • Minimum spacing of 1.8m along span.
  • Maximum dia no more than 1/4 beam depth. (for a 150mm deep beam maximum diameter will be 37mm)
  • Must be located in middle third of beam depth.

Vertical Holes

  • Maximum diameter 1/4 of width of beam
  • Must be in centre of beam
  • Minimum spacing 6 x width


  1. When considering spacing, a knot in the wood is considered the same as a hole.
  2. For holes in Manufactured Timber Joists you should check with the manufacturer’s Website.

Further Reading

Australian Standard AS1684 Timber Framing

The Australian House Building Manual by Allan Staines, published by Pinedale Press.


See Structural Frame for more posts


Timber Frames – Packing

An issue with timber frames is making sure that the frame is bedded securely on the floor slab. . . . You don’t want movement of the frame when the house is completed!

Flatness of the Slab

You may think the building slab looks flat but in practice very few slabs are perfectly level.

The Guide to Standards and Tolerances states “Generally the floor shall be within + or- 10mm of the finished floor level in any room and within +or- 5mm in a 3m length.”

So when the frame is put on the floor it could look something like the exaggerated sketch below.

Making Sure The Frame Is Stable

The key issue is to make sure that the frame is fully supported under the stud positions otherwise the studs can move vertically.

That means that packing will need to be fixed under the bottom plate at the locations shown by the red arrows above.

Packing can be made from hardboard, MDF, Plywood, metal, formica, or specialised plastic packers (sometimes called shims).

It is important that the packers should be secure and non compressible.

They should also not project beyond the bottom plate, otherwise they may affect the later secure fastening of plasterboard and skirting boards.


See Structural Frame for more posts


Openings in Timber Frame

Openings in a Timber Frame Wall Panel usually mean that the Bracing Straps of the Basic Frame can’t be installed.

The following diagram shows typical panel details.

Bracing Panels

The bracing panels replace the bracing straps to keep the frame square and ensure the panel resists sideways forces. They are a sheet  material that is nailed to the studs top plate, bottom plate, and noggins.

Usually the panels are ply although I have seen other materials such as particle board.


The lintel carries loads from above to the studs either side of the opening. The size of the lintel will depend on the width of the opening

Jam Stud

The jam stud in normally the last full height stud before the opening

Secondary Jam Stud

As well as assisting the jam stud to carry the lintel load the Secondary Jam Stud also provides extra stiffness to counteract the fact that there is only one noggin.

Sill Trimmer

This forms a fixing point for a window frame, and also the top fixing point for any Jack Studs.

NB for a small window a Head Trimmer may be used between the lintel and the top of the opening

Jack Stud

The jack stud is a short vertical stud. It can be between:

  • The Bottom Plate and the Sill Trimmer
  • The Lintel and a Head Trimmer

For background information about House Frames see this link: House Construction – The Frame.

Basic Timber Frame Panel

The House Construction-The Frame post explains the background to frame construction.

The drawing below shows a typical standard wall frame

Minimum timber size will be 95mm x 35mm although this may increase for the  following reasons:

  • Additional wall insulation may increase the depth of the frame to 125mm 
  • If the wall requires more structural strength that may increase the timber thickness from 35mm to 45mm.


Studs are the main structural component as they support the main vertical load of the roof and and upper floors.

Normal spacing is at 450mm centers for external walls and 600mm for internal walls unless specified otherwise for structural reasons.

Top Plate

The top plate fixes the top of the stud in position and acts as a mounting point for the structure above the frame.

A single top plate does not have the strength to carry major loads, such as roof trusses or upper floor beams so these should be fixed directly above the studs. 

To increase the strength, if required, a second timber can be added during erection to make a double top plate. This additional timber is fixed to overlap adjacent frames, junctions, and corners, and increases overall ridgidity

Bottom Plate

The bottom plate holds the frame to the base and fixes the bottom of the stud in position .

It needs to be firmly fixed to the base. If the base is uneven packing needs to be installed under the stud positions to prevent any vertical movement of individual studs.


Noggings are the individual short pieces of timber between the studs. They are there to prevent the studs bowing under the load or warping. It is important that they fit exactly into the space.

Maximum spacing between noggons and top and bottom plates is 1350mm. For walls up to 2.74m  high a single noggin meets the standards. Taller rooms and you will need 2.

Diagonal Bracing Strap

The diagonal bracing straps are typically galvanised steel strip which is nailed to each strut. The bracing is the part of the frame that resists any sideways deformation of the frame, such as wind loading.

Although these braces seem insubstantial compared to the struts and plates they are vital to the overall strength. If you find a brace has been cut during construction ask for it to be replaced!

Where there are openings the details in the following link are required: Openings in Timber Frames.

Want to know more?  The following external link is worth a look: Timber Plus Toolbox

House Construction – The Frame

The  Internal Frame is the key structural element in most Brick Veneer House Construction.

In more lightweight structures such as timber cladding and lightweight render it takes on an even more of the structural loads.

The overall frame is composed from a number of individual wall panels, which when fixed to the base, and fastened together, form a rigid box like structure.

Structural Loads

The frame carries several main structural loads:

  • It takes the load of the roof, and any upper floors, down to the foundation.
  • It resists the wind trying to push the whole building over.
  • It provides lateral support for the brick walls.
  • Holds the windows in place.
  • It gives a secure fixing point for the internal wall and ceiling lining boards.
  • In the case of weatherboard or lightweight render construction it supports the outer skin of the building.

Additional Functions

  • Provides a route and fixing points for cables and pipes.
  • Retains insulation.
  • Supports cupboards and shelves.
  • Fixing of building wrap.


See also Brick Veneer