Step-by-Step House Building and Waterproofing by Projex Group

A house is so much more than just four walls and a roof. If you want to make informed choices about the customisation of your future home, then understanding the building process is the best research you can do in preparation. It's better to be safe than sorry, after all.

Luckily, we've done the research for you and broken it down into 9 steps. From talking to construction agencies and setting your plans in motion - all the way to building your home from the bottom up.

Fail to plan, plan to fail

Before the first slab hits the ground, you're going to need to get the initial planning and preparation stages out of the way. We'll skim over the specifics because there is too much to cover in the design process.

Once you've purchased the land that you'll be constructing upon, you'll start deciphering your budget and designing your house plan (either chosen or customised). Now's the time to decide what you truly need and want. If you want a room to expand later for a potential pool, double garage, or just like feeling the sun on your face in the mornings, you should be reflecting this now rather than trying to retrofit it later.

You'll also have to have some discussions about site preparation and zoning control. Each state has a few different zoning controls for a property, so make sure that your new house obeys all of them before starting work.

Step 1: Excavation and foundations

Now's the time to begin hiring some heavy movers to come in and shape the landscape. If the existing land previously had houses built upon it, and you don't need any significant changes, then you can completely bypass this step.

Once all the dirt has been cleared, you should already start to see the floor plan of the house! Depending upon how complex the house layout is, and whether the construction of one area prevents access to others, this step can take anywhere between 1-4 weeks but is usually fairly simplistic:

1. Footings are installed, which are essentially like guide rails for the floor plan of the house. This is the bedrock and acts like a subterranean wall foundation.
2. Concrete or a similar substance is poured into a mould within the cleared earth inside of the footings. This must be high enough to divert water away from the structure.
3. Holes are knocked through the concrete for any utilities or power lines, then pipes are fed in and resealed around.

Foundations are necessary and legally required (based on the Building Code of Australia) parts of construction. They not only provide a base for the house but in some terrains stop warping and expansion. Foundations are required to be designed by a structural engineer and provide protection from moisture and termites. Ventilation for sub-floor spaces and waterproofing that extends about 100mm above soil height are also required implementations to the foundations.

Waterproofing is a vitally important step because many walls are constructed through excavation and backfill. Quite often, the surrounding soil must be refilled past part of the height of the foundation after construction begins, inevitably falling under the soil/water level. By installing a waterproofing membrane, you effectively seal the water below the surface as well as above it, preventing rising damp from the porous underside.

Projex offers two solutions for waterproofing which can be installed at the foundational membrane level; Cosmofin and Wolfin. Both of this high durability, German-engineered waterproofing sheet membrane materials have met the Australian standard for upwards of 20 years within the industry. They provide the highest calibre of protection available for all areas of waterproofing.

Basements, cellars and garages

As an added note, subterranean and partially submerged rooms can sometimes mean that construction occurs beneath the water table (ground and rocks are saturated with water). In this case, we use a method called 'below ground tanking', attaching a series of pumps to continually drain the water to the surface while construction is taking place.

This method continues past the initial foundation stage until the full construction and enclosure of walls around the area are completed. It creates an effective envelope for the room between the soil and membrane. So once the pumps are removed and soil is then backfilled, the submerged areas are protected from any risk of water leakage, while allowing the membrane to repel any further moisture.

Other preparations

Now is also the best time to start acquiring a utility line for any installations you need in the house. Water, septic, electricity, internet, gas, and so on require time and permission to install. Your builder or contractor will handle this, but make sure that they've requested temporary electrical service during construction.

Step 2: Framing

The first picture people think of when they imagine a house under construction is usually the framing.

If foundations and footings are the horizontal guide plan for the house, then frames are the major help in building the vertical. Framing refers to the timber wall skeletons and outlines built by a carpenter. Additionally, framing will start laying the tracks for the flooring, roof, doors, and windows.

If you're not having a construction company subcontract carpentry duties (which is the easier option by far), be sure to spend some significant time vetting and choosing your company. Your carpenter will be one of the most significant contractors who work upon your house, so you'll want to go with somebody reputable, worthwhile, and that you can consult and trust to work with ongoingly.

Once you've sorted out who you're going with, the process beings;

1. Floor timber will be lined across any area with a wall, and then built upwards to resemble the basic rectangular outline of the walls.
2. Each of the wooden skeletons is secured firmly through metal strapping - they must be rigid enough to support the roof framing as well.
3. Boarding is then put in place for doors and windows.

The actual walls won't be built at this stage, but you'll be able to walk around and get a real feel for the interior.

The most significant hindrance during this stage of construction is adverse weather conditions, but luckily this is the final time that it applies. A major part of the framing process is the 'Drying In' stage, which refers to the moment where construction can continue even if it's raining outside.

Roof framing

At this stage, the basic timberwork frame for roof slating will be erected. If you're going for a flat roof rather than pitch, you'll also be waterproofing it now at the substrate level.

The essential process of waterproofing at the roof stage isn't all that different to the ground. It is important though to talk about it separately from the rest of the framing process.

Projex Group supplies waterproofing solutions for flat roofs and are designed to allow a multitude of finished effects after installation, or can remain exposed, as it's UV stable. Both Wolfin and Cosmofin are sold as complete systems. Purchasing one not only includes the membrane itself, but the factory bonded PVC profiles, premade internal and external corners, detailing strips, adhesives and welding solvent - providing the 'total waterproofing solution'.

Slats and sheathes

This is the final major part of the checklist before work begins on the interior. Oriented Strand Boards (OSB) are installed into the timber gaps as a rudimentary wall covering, closing the house off from weather and providing a true backbone for the internal and external walls.

At this stage, your carpenter will usually install your windows and doors for simple ease of construction. With these installed, sealed, and completed, the house is now effectively wind and weather-proof, and ready to begin internal construction.

During this time, it's a good rule of thumb to start purchasing and planning your internal projects ahead of time. Having cabinets, installations, utilities, and work surfaces prepared well ahead of time means that your crew can begin work with the actual model specifications, and immediately slot them into construction.

Step 3: Presentational exterior

Now that the bare bones are completed, you can start creating the house exterior to your design. Your exterior siding, no matter what you end up using (e.g. brick or stucco outer wall), will be applied here.

Once the exterior siding is completed, your house will be starting to take shape in a way that's starting to look livable. However, there are still a few finishing touches on the exterior to complete;

1. This is mostly a series of simple additions such as soffits, the covering of any architectural overhangs with tiles or slating, or any friezes you may want to present.
2. The roof has to be tiled or shingled, then you'll also need to flash with sheet metal or lead to prevent additional leakage or seepage. Unless of course using a flat roof with our Wolfin or Cosmofin solutions.
3. Decide on the positioning and inclusion of balconies and terraces around the exterior of your home. Whether the substrate of the balcony is concrete, timber, fibre cement sheeting, steel etc. waterproof membranes should be installed directly onto the substrate before screeding to falls and tiling.

Once your roof looks like a roof, and your walls are looking like walls, it's time to start bulking out the interior.

Step 4: Interior utilities

It should be noted that unless there are multiple extraordinary factors at play, the external work mentioned throughout step three can be done simultaneously with step four along with any other internal design to save time.

Lines and piping

The first sections of the interior that you should now be covering, are those that we laid the groundwork for during the foundation stage. Since the exterior and covering are complete, and the dry-in process has finished, there's no risk from weather or environmental elements.

Here is a short checklist of the things you should be planning for this stage (including things such as electricity that your builders should be subcontracting regardless):

1. Permanent electrical fixtures (separate from any temporary ones used during construction).
2. Phone lines.
3. TV Lines (if separate).
4. Internet wiring.
5. Plumbing and sewerage.
6. Any security systems you'd like to install.

After a quick (and compulsory) safety inspection, you'll be ready to set these up in the future. Right now, all you're doing is laying the groundwork in the shape of wires rather than actively connecting them to services and appliances.

Insulation

Insulation batts will now need to be installed between the wall framing before any drywall/plasterboard goes in. This can be done very quickly, and without much expertise, but it's important to do so now rather than later.

Keep in mind that insulation/ventilation for your roof can be a great investment to protect against leaks and save on power bills.

Step 5: Presentational interior

Plasterboard

Now that the insulation has been placed, you can begin securing your plasterboard (often referred to as drywall in America, if you're looking at tutorials).

Plasterboard is attached directly onto the timber framework and constitutes what you would think of as, an actual interior wall. Once this is in place, the walls are functionally done, requiring only aesthetic additions from this point, and finishing of fixture areas such as the doors and windows.

Next, depending on whether you're going to be using a wooden trim or a painted trim, it can be worth your while to prime your plasterboard now to prepare for painting later. The reason it's a good idea to do this now is that without any other major surfaces to worry about, and after taping up doors and windows, you can be a little more sloppy with your coverage without worrying about getting primer on floor trim.

An added benefit of priming now is that you'll be able to see plasterboard imperfections through the dried primer, making this the perfect time to fill them as well.

If your trim doesn't require painting, then you can obviously skip this step.

Flooring

The walls are done, and now it's time to get the major steps of the floor down. This includes:

1. Sourcing, sanding and finishing any hardwood.
2. Installation of any vinyl, stone, and/or ceramic tiles for bathrooms, patios, kitchens, etc.

Interior trim

By now, you should have sourced any permanent utilities, work surfaces, and cabinets. Once these have been fitted to your floor plan, you can then begin to erect any further trimming you have planned for the interior.

You should also consider finishing any painting or further installation of trim ASAP at this stage if left unmanaged it can lead to warping in the long term.

Step 6: Final utilities

Plumbing

Assuming that you've already finished flooring and general installation of fixtures, you can now have a plumber come in to finish piping for any areas that require it. Your bathrooms will be installed here, as well as specific laundry fixtures and kitchen fixtures.

Electricity

After the initial setup by the plumber, the electrician will provide power to whatever installations occur.

After this, the electrician will provide power to whatever utilities remain that still require finalising, such as air conditioning, lighting, power points, and appliances.

Water retention facilities

If you're installing a water retention facility such as a water tank on your property, waterproofing is of high importance to ensure it does its job correctly. Most tanks are concrete or concrete-filled blockwork, so Wolfin and Cosmofin waterproofing solutions are perfect for immediate application. As these solutions are pre-formed sheet membranes supplied in a roll form, they are more efficient, secure and are a long-term alternative option. Unlike liquid membranes, Wolfin and Cosmofin Sheet Membrane waterproofing solutions are immediately ready for use after installation and don't require any curing before the water tank is ready to use. These products also will not re-emulsify underwater and can be used for permanent immersion.

It's worth noting here the benefits of water retention facilities if you haven't already thought about it;

• Provide an excellent way to drought-proof your home.
• They help you save money on your water bill.
• Reduce negative environmental impacts:
  • Collect waste water from your kitchen, laundry and shower, then reuse it for flushing water in your toilets.
  • Provide a way of collecting rainwater for your garden.

Step 7: Tidy up, scrub out

At this stage, the house itself is complete, congratulations! It resembles a livable house, if not a home, and the vast majority of the subsequent work after this step is up to either you or an interior designer.

As a result of home construction, there's going to be a lot of accumulated rubbish that'll need to be hauled, as well as soil to fill in, beaten paths to make pretty, and landscaping to be done.

You should finish all of this before continuing any further, as the rest of the remaining tasks require somewhat of a clean slate to begin. Laying things such as an indoor carpet is an important next step, but it can't be done if there are debris and dust everywhere from the installation process.

Step 8: The final construction

There's a few odd-jobs remaining, but construction has firmly begun to wrap up at this stage.

A driveway is only really possible to build once the massive flow-through of construction equipment peters out, so you're invariably going to be constructing it now rather than earlier.

On top of this, now is the time to begin landscaping. Unless you're going with pre-grown plants and rolled-out grass, this is a process that will take considerable time to get fully settled in, so starting ASAP and save time in the long term.

This is also a point at which people, especially those getting towards the end of their budget, begin to skimp. This can be fine, to a degree, as landscaping is probably the easiest change you can make to a property. However, remember to allocate and leave enough of a budget that there won't be a huge disparity between your beautiful new house and the dusty land lot it occupies.

Step 9: Residential waterproofing

We've been pointing out the importance of waterproofing in the early steps, and throughout the building process. However, that doesn't mean it's not just as important to waterproof again, now you're reaching the end.

Keeping your exteriors protected from the elements, and having your interiors adequately waterproofed is an essential step to maintaining a functioning, issue-free house. With effective waterproofing measures in place, you can keep your furniture and other possessions safe from water damage.

General surfaces that require waterproofing include roofs, walls, balconies, and foundation pillars. As well as other key areas like bathrooms, toilets, kitchens, and laundries where water usage is heavy.

With efficient waterproofing, you'll be saving your home from;

Concrete cancer

Prevent concrete cancer and improve the structural integrity of the building.

Electrical fires

Caused by wiring that may be affected by water damage.

Rising damp

Rising damp is caused by heavy condensation in the building. It can obliterate structural integrity and create health problems for those living in the building. This can be due to rising groundwater seeping through the walls of the house or leaks and damages from an existing water source e.g. drainage. The solution is to apply high-quality waterproofing with sealers or membranes on any porous materials like stone, masonry, concrete, and grout.

Extreme weather events

As well as appropriately waterproofing the exterior of the building, other things to consider to prepare for extreme weather can include:

• Installing a sump pump in your basement and setting it to switch on automatically if the level becomes flooded.
• Make sure your garage doors are reinforced.
• Plywood panels are worth considering if you're in a storm-prone area.

Maintaining your house once you've finished building

Once you've completed your final build, you can enjoy your completed home. But don't forget about ongoing maintenance and protecting it from the elements. From the roof to the window frames, these are the places that should be checked regularly to catch any issues:

Roof and gutters

Have a professional inspect the roof for any causes of leaks, such as loose or missing tiles, lifted flashing, and blocked or rusted gutters. It's a good idea to have your attic checked at the same time, as your attic will quickly reveal if your roof is leaking.

Check the gutters and downpipes to ensure they're still securely hooked up to your stormwater system. Clean them out if there's any debris. If it's safe to do so, checking during a rainy day can be helpful because you'll be able to see right away if there's a blockage.

Basement

Your basement could be a high-risk area when it comes to leaks, and the most common cause of basement leaks is poor drainage in gutters and downpipes. It's a good idea to also check your crawl space for mould while in the basement.

Plumbing

Plumbing leaks can lead to warping, rotting, and discolouration of walls and floors. Causes of plumbing leaks include poorly waterproofed showers, leaking toilets, and leaking pipes in kitchens and laundries.

Window and door frames

Check frames for loose, cracked and worn putty, signs of rot, or poor fitting. Apply waterproof paint or sealant to all woodwork and replace any faulty or cracked panes.

Interior and exterior walls

Look for algae and mould on walls and cracked pointing between bricks, these can be signs of leaks that could lead to bigger problems. Replace or repair where necessary.

• Consider having the caulk on your bathroom and kitchen fixtures replaced every two years as a preventative measure against water leaks.
• Check the base of your shower for cracks or leaks.
• Review the hoses and connections on your washing machine and dishwasher for any signs of damage or seepage (including a water heater if you have one).

A quick check can be done by turning off all taps and appliances using water, then waiting for 30 minutes. If the water metre shows water consumption during this time, you might have a leak in your home. If you have a pool, remember to check for leaks once in a while.

After final construction, the rest of your duties are mostly inspections, finalisations of payment or loans, and beginning work furnishing the interior of the house to make it your own. Whether you've built a new home for you, your family or for investment purposes, you can know now that the hard work is over. Other than that, you can feel free to sit back and relax!

If you're considering building a house, get in touch with Projex Group or head over www.projex.com.au to discuss the waterproofing solutions, protective matting, and pipe sealing that will be necessary for building a secure and long-lasting home.