Month: August 2013

Retaining Walls – Gabbions

Gabbions are big wire baskets filled with rocks.

The baskets are typically available for retaining wall use in 1m x 1m x 2m units. and you arrange the rock fill yourself.

Gabbion walls can be described as a Permeable, Steel Reinforced, Low Skill, Dry Stone Wall.

Low Skill however doesn’t mean no skill so don’t just tip the rocks in. For best results the rocks need to be adjusted to pack them tightly into the baskets.

In my view the best looking gabbions are the square mesh ones like the photo above.

If appearance is not an issue then there are these standard units, on the right, that have a more basic mesh.

Although the wall is permeable and doesn’t need an aggi drain behind it I would still advise a layer of fine gravel. This prevents fine soil particles being washed through the gabbion, as has occurred in the lower section of this wall.

 

To know more about retaining walls follow this link: Understanding Retaining Walls

Love the Display Home

BUT CAN YOU AFFORD IT?

When you visit a Builders Display home you will probably be given a price list which quotes the Basic Price for the house you are looking at.

Don’t be fooled!……… The feature you see in the Display Home will add much more to the cost.

The following table provides examples of the value of upgrades added to Display Homes around Melbourne.

Builder

House

Base Price

As Displayed

Percentage Increase

Burbank

Prescott 1900

$152,200

$205,489

35%

Carlisle Homes

Illuka 25

$179,900

$248,895

38%

Dennis Family Homes

Hastings 241

$177,900

$251,400

41%

Hallbury Homes

Vogue 39

$314,900

$484,900

54%

Metricon

Delta 22

$169,200

$253,262

50%

Porter Davies Homes

Montague 21

$161,900

$255,563

58%

Simmons

Villa Vitoria

$294,600

$479,038

63%

All figures as published in the Melbourne Herald Sun 17 August 2013

You can see figures for 2017/18 prices here: Display Home Upgrades

Additional Costs

In addition to the displayed costs you might have to pay extra for:

To get some idea about how the costs can add up follow this link: What Will It Cost.

Also see

 

Condensation

Condensation,  a minor inconvenience,  or a major problem?

A little condensation on windows is easily dealt with, . . . . . .  but heavy condensation in poorly ventilated corners can lead to mould damaging your walls, ceilings, or even your clothes.

Why does Condensation Occur

Condensation in a building occurs when warm air, containing water vapour, comes into contact with a cold surface.

As the air cools it can’t hold as much water vapour so the excess changes into liquid water which is deposited on the cold surface.

The  water usually appears as surface condensation as water droplets or water film on cold surfaces, typically windows.

Condensation occurring on cold walls and ceilings is a major issue as it is when mold problems start. Of particular risk are wardrobes on  an external wall as there is a cold surface and a lack of ventilation.

Sources of Water

Here are five main sources of water vapour in the home

  • People – A typical adult will lose around 0.8L/day of water, half from skin evaporation, and half from breathing.
  • Bathrooms – Not just the obvious showers and baths, its also those drying towels and bathrobes 
  • Kitchen – Kettles, Pans, dishwasher, and the microwave will add water vapour
  • Un-Flued Combustion – Portable Gas Heaters, Gas Hobs, Bio Ethanol Heaters, even Candles, all emit water vapour into the room as they burn.
  • Laundry – Unvented Tumble driers, Airing Clothes.
  • Evaporative Cooling – Because it is mainly used in summer less of a problem, but can be an issue on cold nights.

Preventing Condensation Damage

Action to prevent condensation damage involves looking at both insulation and ventilation.

Insulation. Additional insulation in walls or ceiling will keep those surfaces warmer which will reduce the risk of condensation damage in most rooms .

Ventilation In bathrooms and kitchens the more moisture laden air means that insulation by itself will not be enough. The moist air needs to be effectively extracted to prevent condensation being an issue. (Although I have previously posted about Heat Loss due to Ventilation some  ventilation is  needed throughout the house)

Role of Double Glazing

Double glazing is often suggested as an answer to condensation however this is not really the case. As the windows are now less cold there is less surface condensation on the windows, so it looks like the issue has gone away. The problem is that without removing the moisture laden air the risk of condensation on walls and ceilings is increased.

See this link to find out why I prefer a separate Extraction fan in the Bathroom: 3 in 1 Bathroom Heaters

To keep moisture out of the insulation materials see this link: Vapour Barriers

 

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.

Lintel

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.

Front Facade Fail

A lot of people like a large garage……. but you need to be careful if you have a narrow block.

The size of the garage dominates this property and makes it look more like an industrial unit than a home. It isn’t helped by that really plain front door!

And here is another, more interesting front door, but still looks like a mechanic’s place.

Score of 1 /10 for kerbside appeal.

 

For more unusual houses and fails go to What the………….?

 

 

Different Soil Classification Results

When you look at a new house block its always worth asking the Developer’s Agent what the Soil Classification is ……….. Only don’t take what you are told too seriously!

Usually the developers opinion is going to be that the site is going to be better (lower site costs) than your builder.

To understand why you need to consider the differing situations of the Developer and the Builder.

The Developer

  • May have done 20 or 30 tests over the whole development.
  • Is mostly interested in selling blocks
  • Since the tests were taken has had sewers and drains constructed on the site.
  • Probably done some spreading of fill from roadworks construction and site leveling

The Builder

  • Has had 3 tests done on your block.
  • Knows that even with the three tests the information represents less than 0.01% of the soil under your block.
  • Want to be sure the foundations are strong enough.
  • Want to avoid claims, from you, for foundation movement causing structural cracks.

If I got a soil classification from a Developer I would ask the Builder what extra site costs would be required for that soil, and then budget for at least another $5,000.

 

For lots more information why not get the Guide to Buying a Block only $4 at this link: Buying a Block

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

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

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

Rainwater Collection Fail

How Not to collect rainwater!

I suppose its cheap…….but it’s not the most convenient for filling your watering can from.

You can also see that algae is growing in all those open containers.

It’s not something most of us would want on our front gardens!

On the plus side it probably looks very spectacular in heavy rain as the water overflows into the various containers.

 

For more fails and unusual houses go to What the………………….?

 

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