Home Buyers / Home Owners

Home Builders & Renovators - Ask a Question

Further Questions & Answers 2

Homework

The following questions and answers are applicable to Victoria.

Edited versions of these articles appear in the occasional Homework column in the Wednesday edition of Domain, The Age.

Asbestos

Q: I have a large bungalow in my back garden that probably dates back to the 1950s. It seems sound enough so I want to convert it into a playhouse for the kids. How should I remove the damaged AC sheet from the walls.

A: You shouldn't - asbestos removal is a DDIY job …. don't do it youself.

Many materials considered safe in the past have since been found to be health hazards - asbestos is one of them. Asbestos was incorporated into a variety of building products prior to 1983, the most common being asbestos cement sheet or "fibro". AC sheet was commonly used as wall cladding, roofing, interior panelling and eaves lining. The asbestos in these products is usually embedded in the sheet but if the sheets start to weather or break the harmful fibres can be released. In this case, removal of the sheeting would probably be wise, however, it should only be done by professionals. They will wear protective clothing, take care not to break the sheets and securely wrap them for proper disposal.

The best advice? Check out the roofing to see if it needs replacement as well and get three quotes from licensed asbestos removal contractors. If the building is powered ask a registered electrical contractor to check the wiring and also test the interior paintwork for lead content. If in doubt ask an Architect.

When the earth moves

Q: How should I repair a crack that has appeared in the side wall of my house? It is a brick house and I think it was built in the 1920's.

A: Cracks in brickwork aren't necessarily an indication of imminent disaster...they're often a sign that the earth has moved for you!

Soil movement is caused by changes in its moisture content and is more evident in inland clays than in coastal sands. Whilst excessive moisture (caused by an undetected leaking pipe, for example) causes soil to swell, drying causes it to shrink and our continuing drought is the cause of many a recent crack.

Aided by increasingly thirsty trees, it's slowly drying out our soil and causing movement beneath our homes, particularly affecting older building stock. Thankfully, these days we're better at predicting soil behaviour than we were in the "good old days" - we design new homes for local conditions using techniques such as pier and beam footings or movement control joints.

According to accepted industry standards, cracks less than 5mm wide aren't necessarily cause for concern, however larger cracks can mean some reconstruction work. If the crack is a result of foundation shrinkage it may well close up when the soil becomes moist again. This will probably occur naturally during the wetter months, however you can hurry it along by re-hydrating the area using a drip-watering system (be sure to check your local water restrictions first!). If the area around the base of the wall is paved, consider replacing the paving with porous material or planting - this will ensure that water permeates the soil rather than running off.

Above all, don't fill the crack with mortar - use a flexible, exterior grade sealant. If and when the foundation soil does swell back into its natural state the brickwork will want to move back into place and an inflexible filler will simply induce a crack elsewhere. Alternatively, just measure it and keep an eye on it to see if it's getting better or worse. If it doesn't close up or if it gets bigger, it's time to seek some professional advice - ask an architect.

Grey power

Q: I want to re-use the water from my laundry on the garden. What is the best way to do it?

A: During the last year or so Victorians have enthusiastically embraced the idea of waste water re-use. The pressure on our water reserves continues to be significant (as a builder said to me last year "...we'll be drinking mud if it doesn't rain soon!") and any action by home owners to conserve water is commendable.

Having said this, forethought and planning is important when considering the use of what is really contaminated water. As a developed city, Melbourne has sophisticated water supply and disposal systems in which millions (perhaps billions) of dollars has been invested over many decades. The money isn't spent on a whim - it's a matter of ensuring public health and safety.

Firstly, some definitions..."grey water" is waste water from showers, baths, hand-basins, spas, sinks, troughs, washing machines and dishwashers, whilst "black water" is waste water from toilets, urinals and bidets.

Both types of water carry contaminants including detergents, dirt, chemicals, food particles, grease and, in the case of black water, faecal matter (the less said about this the better!). Black water is clearly unsuitable for re-use without extensive treatment, however grey water can be re-used if appropriate precautions are taken.

Clearly a properly designed and constructed collection, storage, treatment and reticulation system is preferable, however a simple and relatively inexpensive "diversion" system can be effective, bearing in mind the following guidelines:
* Only divert low risk grey water such as shower, bath, basin and laundry rinse water
* Don't use grey water on leaf vegetables or vegetables that are to be eaten raw (consider this next time you're enjoying a home grown salad!)
* Don't store grey water for more than 24 hours
* Don't allow grey water to pond and only use it during warm, dry weather
* Ensure that the system can't block or that the waste water will discharge into the sewer if it does
* Don't allow pets or children to come into contact with it
* Don't allow it to enter storm water drains
* Watch what's happening to the area you are "grey watering"

Above all, make sure no waste water runs or seeps on to your neighbours property (they may not share your passion for water conservation), check with your local Council before you do anything and involve a licensed plumber in the installation.

Of course, the best way to conserve water is to use less, but that's another story.

The best advice? Do what you can afford...if you're not sure, ask an architect.

Out of the shadows

Q: My wife and I want to put a side extension on our house. Are you able to tell me a formula for working out overshadowing on September 22nd at 9am and 3pm?

A: This is a fair bit more specific than most of the questions we get, but it's another good one. It sounds to me as though someone has alerted you to one of the key objectives of ResCode...either that, or you have an uncommon interest in sun shading!

Amongst many other requirements, ResCode states that buildings should not "unreasonably overshadow existing secluded private open space". The open space referred to is usually that of a neighbour, but open space on your own property can come under consideration if you live in a unit, for example, or on a small allotment.

It goes on to stipulate that at least 40 square metres of the space should be able to enjoy at least 5 hours of sunlight between 9am and 3pm on September 22nd (the equinox).

The logic (as far as I can see) is that if sunlight is available to an area of open space in September, then it will penetrate the space during summer when the sun is higher in the sky. The extent to which it penetrates during the winter months depends upon the configuration of the space, but (surprise, surprise) ResCode is a step ahead. In September, the area lit by the sun must be at least 3 metres wide - this helps to ensure that even the longest winter shadows shouldn't completely cover the area.

If the requirements sound complicated, try designing a building around them! It often requires a careful balance of boundary setback, wall height and roof pitch that can generate some interesting forms...

Of course, there are times when it can be impractical or even impossible to comply with the overshadowing guidelines, in which case an application can be made to Council for some concession. This can mean the preparation of a comprehensive submission that may require - and here's the thing - consent from the neighbour.

As far as a formula is concerned, shadows are determined by the location of a site, the time of year, the time of day and the height of a wall. In Melbourne on September 22nd the suns altitude is about 35 degrees above the horizon at 9am and again at 3pm. In the morning, the sun's rays come from 59 degrees east of north and in the afternoon they come from 59 degrees west of north.

Armed with this information, a drawing board and an adjustable set square you can plot the shadow cast by any building on the day. Alternatively, you can activate the appropriate command on your PC if you have access to computer-aided drafting software.

Then again, you could ask an architect...

On the outside

Q: What are your thoughts on outdoor entertaining areas?

A: As I write this, it's one of those drizzly Melbourne days on which everything is bluestone grey and the last thing on anyone's mind is alfresco dining!

Nevertheless, a contemporary Melbourne lifestyle demands a venue for outdoor living and an exterior entertaining area is high on the list of most home-builders and renovators. They can be expansive poolside terraces or pocket-handkerchief courtyards, elevated or at ground level and for group entertaining or quiet contemplation. Whatever the purpose, the key feature of a well-designed outdoor living area is sensible orientation and protection from the elements.

A northerly orientation is generally the most desirable however an eastern aspect is also pleasant in the mornings, although it will be shaded in the afternoons. A western orientation is ideal for growing cacti and a southerly one for growing mushrooms...human rarely flourish in either.

Care must still be taken to shield even a north-facing deck or courtyard from the summer sun. A roof, a sail or a pergola will generally do the trick, however anything permanent might exclude the sun when you want it most. Deciduous planting (a grape vine, for instance) can be helpful as it will allow the sun to penetrate during the cooler months, as will an operable roof system or retractable shades. Protection from late afternoon summer sun can really only be achieved using a wall, vertical screening or planting.

Another important consideration is the relationship between the interior and the exterior of the house. If the purpose of the outdoor area is to accommodate a 12-person barbeque, then circulation between the kitchen, the living area and perhaps the property entry should be considered. If it's to be a secluded 2-person courtyard then access and views from the rest of the property should be controlled. In this sense, an outdoor living area should be regarded as much a part of a home as a bedroom or a bathroom and as carefully planned - if the area is likely to be a noise source it's probably inappropriate outside a nursery or a study.

It's also worth thinking about the level of the area in relation to the floor of the house and the garden. A paved courtyard at ground level will relate well to the garden however proper drainage and convenient access from an elevated house require some forward planning. A raised deck, by contrast, will separate the house from the garden but will create a smooth, step-free transition between indoors and outdoors.

An elevated deck may even enable views to be enjoyed, although if it is more than 800mm above the ground a view into your neighbour's garden must be prevented. If it's a metre or more above the ground it needs a balustrade around the perimeter to stop people toppling off - this may need careful consideration to avoid compromising a view.

Finally, a new outdoor living area may require a Building Permit or in some cases a Planning Permit...if in doubt, ask an architect.

Renovator's delights

Q: We have an old home that's had several additions over the years. Is it possible to renovate it ourselves to obtain a more cohesive style?

A: Home renovation isn't a recent phenomenon - it's just become more glamorous recently. Apart from the appeal of many older homes, they are usually well-located and provide real opportunities for capital growth if carefully handled.

Older homes have often been altered or added to since they were originally built. It's not unusual to see houses, particularly period cottages, which have undergone several face-lifts over the years as families have moved in and out, as lifestyles have changed and as repairs have become necessary. A common sight is the "cascading skillion" - a series of lean-to additions at the rear of a home with each roof tucked under the eave of the previous one.

The first priority of any renovator intending to retain previous additions should be to ensure that they are safe. One in four of the homes inspected by Archicentre has some form of illegal building evident - a low ceiling, steep stairs or inadequate natural light or ventilation, for example.

It's reasonable to assume that such work was done without the necessary permits or inspections so the condition and adequacy of the structure, the wiring or the plumbing is uncertain at best. Some investigation should be carried out to establish the extent of any reconstruction work required (and its likely cost) before decisions are made about retaining that "charming attic" or the "sun-filled sitting room".

This done, the design process can begin, taking into account circulation, zoning, orientation, views, materials, lifestyle needs, the form of the house and of course the budget. It's sometimes useful to think about the building objectively...as an empty vessel within which your particular requirements need to be accommodated.

Style is clearly a matter of individual taste and preference. Many renovators want to preserve or recreate period details while others enjoy the freedom of more contemporary materials and spaces. The choice is yours and it can be worth exploring the possibilities of both approaches.

In any event, it's important to do your homework first. Objectively assess the home so you can decide what to keep - don't assume it's condition or it's adequacy for your needs.

As far as "doing it yourself" is concerned, that's another story...

Renovator's delights

Q: We have an old home that's had several additions over the years. Is it possible to renovate it ourselves to obtain a more cohesive style?

A: Doing-it-yourself is an Australian tradition that's alive and well, despite the ever-increasing complexity of the home design and construction process.

Despite its trials and tribulations (not to mention the legal obligations incurred) many Archicentre clients give owner-building serious consideration, particularly if they have the time and the expertise necessary to manage a construction project.

The conventional approach to home building and renovation sees a contract established between the owner and a registered builder. Under the terms of the contract the builder is responsible for scheduling and supervising the work, sourcing and managing sub-contractors and arranging the purchase and supply of materials. Perhaps most importantly, a registered builder is required by Victorian law to warrant the structure of a building for a period of 6 years from the completion of the work.

As far as the law is concerned, owner-builders are deemed to be builders if they take on the role of a head contractor. Owner-built homes or renovations valued at more $12,000 cannot be sold within 6 years of completion without an insurance policy that guarantees the following:
* That all work was carried out in a proper and workmanlike manner
* That all materials used were of good quality and suitable for the purpose
* That all work was carried out in accordance with the applicable laws and regulations

Before issuing a policy insurers require the building to be thoroughly inspected by an accredited inspector (such as Archicentre) and given a clean bill of health, including the identification of any second-hand materials used in the work. Any apparent defects are noted on the basis that the insurance policy only covers defects arising after the inspection.

Clearly anyone taking on the challenge of owner-building needs the ability to not only manage the construction process but to rigorously control the quality of materials and workmanship. There are courses available to prospective owner-builders, there are management systems that can provide step-by-step assistance and there are savings to be made if you know what you're doing.

As with most areas of home buying, building and renovating, however, it's important to understand the process before you make your decisions...if in doubt, ask an architect.

Out, damp spot!

Q: My brick house appears to have rising damp. The most affected area is the wall outside. A concrete path about one metre wide runs the entire length of the house - could the path be contributing to the damp problem?

A: Damp houses can be unhealthy and costly to remedy - knowing more about the issue can reduce the worry and expense. Most dampness problems can be cured or minimised by simple remedial work but a few will need substantial outlays, so it's important to know what you're dealing with.

Rising damp occurs at the bases of walls. Water accumulating there can "wick up" through bricks, blocks or stones and through the mortar in which they are laid. Damp-proof courses are there to block this upward movement of moisture but they can sometimes be ineffective.

The most common sign that Archicentre sees of rising damp is a lifted surface finish. As a wall with rising damp dries, moisture will be drawn to the surface and find itself trapped beneath the wall lining and coating, resulting in staining, blistering of the wall coating and eventually crumbling of the wall lining. Another common indicator is efflorescence - salt crystalline formations on an external wall surface.

The causes of rising damp are various, but the problem is usually caused by a damp-proof course being disrupted, breached or failing.

The minor movements of all structures sometimes cause brittle dpc's to crack thereby creating a path for wicking moisture. The slate and mortar dpc's in older brick homes are most likely to suffer, but tar and sand dpc's can also become brittle enough to crack.

A change to the conditions at the base of the wall is the most common reason for a building to develop a dampness problem. Raised garden beds or paving are a common cause of a dpc breach, particularly if the new surface level is above the line of the dpc…the best dpc in the world won't work underground! Dampness caused by poorly-laid paths can be cured by rebuilding the path below the dpc and by sloping it away from the house or installing drainage grilles in the path nearest the wall and connecting to the stormwater.

Blocked sub-floor vents are another common cause, preventing natural evaporation beneath a building - removing the obstruction will frequently fix the problem. Increasing the number of vents will further improve air circulation and assist the evaporation of wicking moisture.

Repair of leaking water pipes or drains will eliminate them as a cause of the problem, but remedying the damage will often require additional effort.

Where these remedies are ineffective or impossible it may be necessary to embark on a process of replacing the damp-proof course. There are a variety of ways of doing this, with the most common being the insertion of a new membrane or the creation of a chemical damp-poof course.

In either case, expertise is everything. Get three quotes for any works and ask for referees…if in doubt, ask an architect.