Australia Weather News

Authorities have begun the huge task of assessing the damage to properties affected by floods in north Queensland, with more than 1,500 homes having already been assessed so far.

Meanwhile, Tasmania and New South Wales are dealing with the fallout of massive bushfires and the damage it has caused to homes in the area.

So how does flooding affect a home and does it have the same impact as a cyclone or a bushfire?

TimberED Services' engineer Geoff Boughton says depending on the kind of flooding, a home that has been hit by water can still be saved.

"[A flood] is quite invasive but it's not as terminal for the structure itself as something like a bushfire or a very severe cyclone," he said.

But it might not be your first impression upon first walking into a recently flooded house that has already been cleared by authorities for electrical issues.

Usually, one of the first thingspeople notice is the smell and the damage to their belongings.

"They're quite traumatised by the fact that their stuff has been damaged, that the house smells and then people come along with fire hoses and wash the house out, clean out the mud, remove all their stuff in skips outside," Dr Boughton said.

"They're then left with an empty shell that still smells and they realise there's more work to clean the house out.

"It's quite a spread-out trauma — the shock of finding their stuff ruined, the invasion of having people wash out their house, throwing out their belongings in a skip, and then realising they've got to start ripping out parts of the house to help it become liveable again."

Here's what he says are some ways a flooded home could be affected (excluding damage to natural gas lines or electricity).

(Before we get underway, it's worth pointing out that this is a general idea of how flooding can damage a home. The impact on your home will depend on a number of different factors.)

What kind of housing damage can flooding cause?

It depends on thetype of flooding(fast moving or slow rising) that has occurred,how much water has entered your houseand howlong it's been submerged.

There are also a number of ways your home can be affected by flooding, including:

Usually, if your place has been partially submerged or remains substantially flooded for weeks, more work is required to fix the building.

"[But] in many cases, the homewould not be 100 per cent destroyed," Cyclone Testing Station research fellow Daniel Smith said.

"There are many factors but the bigger ones are the flood depth, duration of flood [how long the building materials are under water], how long it takes to dry the building out [repair team can get in with drying fans, etc] and the types of materials used in the building."

Depending on the type of home you have, everything reacts differently to stress and trauma.

If your floor is flooded, it's not as simple as mopping up

It depends on what kind of floor coverings you have, but the general advice is thatif it's been severely affected by flood waters, it's contaminated and will have to be removed.

That includes soaked or contaminated carpeting, rugs and padding and potentially linoleum (if it's broken, brittle, and cannot be salvaged), QBE Insurance said.

Structural floorboards might be able to withstand some water, and if you're in a highset house you may be able to air the flooring out over a couple of months because there's quite a lot of air passing over the floor both on top and underneath, Dr Boughton said.

In low-set houses, you will also probably need toclean and dry out the space under the floor,and allow air to circulate. Things like plasterboard and furniture may also need to be checked for water damage.

"The floor may buckle a little bit because once it gets wet, it swells up and buckles and if that's the case, some remedial work will be required down the track," Dr Boughton said.

But as for the structure of your home,it should be fineafter the water recedes.

Doors and windows won't fit, cabinets become fluffy

Waterlogged doors and timber-framed windows will most likely expand.

"It's very common after inundation thatdoors swell… whether they be solid wood doors or hollow core doors," Dr Boughton said.

"So, they may look fluffy and horrible and jam in position. It is likely you'll need to replace all of your internal doors in that house."

Generally, windows shouldn't be re-paned to make them fit their frames until the timber is back to its normal moisture content, which may take several weeks, QBE Insurance said.

And if there has been any kind of water inside your cupboards (especially if you have melamine cupboards in the kitchen) they will likelyswell up and become fluffy.

"They may get soft and collapse in the weeks following the flood, if you don't take all of your plates out of them," Dr Boughton said.

"Often the cabinetry throughout the house may need to be replaced. For example, kitchen, laundry and bathroom cupboards."

If your walls are waterlogged, there might be hidden surprises

It depends on how your walls are built but if they are the standard concrete masonry blocks, they will hold a lot of water and take some months to dry out.

Dr Boughton says if it's aplasterboard wall on a timber frame and has been exposed to flooding, it is likely the plasterboard will need to be removed to allow the frame to dry out.

You should also watch out for places where cleaning is often overlooked — for example, within the cavities of timber, brick veneer or cavity brick walls.

"There's not a lot of air movement in the wall void so it can take a very long time for the moisture to dry out and if the plasterboard is not removed mould will grow in the cavity and eventually grow through the plasterboard," Dr Boughton said.

"In most cases, the plasterboard has to be removed to at least the depth of water inundation so all the mud behind it can be cleaned out and the cavity given a chance to dry."

But even then,drying out is likely to take a long time — possibly months— depending on the type of construction.

Then there's the mould to worry about

Queensland Fire and Emergency Services officers doorknocking the region have already reported mould is becoming worse by the day.

It canthrive in damp areas(like wall cavities) and can be dangerous if it's not brought under control.

"If cavities are not properly cleaned out and dried, the mould is going to grow inside the wall cavity and the house will start smelling," Dr Boughton said.

"Then the black mould will start coming out through the plaster board and on the surface of the wall.

"Mould may also promote fungal growth that can lead to timber decay."

And you could have structural damage

Dr Boughton said if the water was fast flowing around buildings — which he says footage of some parts of Townsville appears to suggest — it couldundermine the foundations.

"Fast-flowing water can scour soil next to walls or around posts if it's a high set house or a low-set house on posts," he said, adding that it could still be repaired to secure the footing.

"Scour around low-set houses may be more of a problem but even then there are some grout injection techniques in which grout can be pumped under low-set houses or a concrete slab to build up any voids underneath the slab."