Tips & Tricks

Five Questions with Home Renovator Georgina

A big thank you to Georgina and her family for asking Cornell Engineers to provide structural engineering for their home renovation (house raise and build in under project) in Milton.

We asked Georgina five questions about the process so far (design and documentation stage). Here’s what Georgina had to say!

It’s early days in your house renovation project so far. What obstacles and problems have you had to solve already that you didn’t expect? Have you overcome those problems yet? 

We really wanted to have some off street parking but without lifting or moving the house it wasn’t possible. We made the decision to leave that given the budget required was too much. 

We also want a pool, this was going to be an issue with the slope of the land and stormwater drains plus the limited access we have at our property. Luckily we have found a position for the pool that suits and digging for the pool can be done early on in the project when we have excavators on site. I’m sure there will be more obstacles that pop up along the way but so far so good! 

What were the critical factors in the decision to stay and renovate instead of selling and buying a different house?

We did have a good look at the market and went to inspect quite a few houses before we made the decision to renovate.

All the properties we looked at were good but always with issues that would have to be fixed with a small renovation anyway or not in a great location. We decided in the end that being able to work with what we had already to create a home that is perfect for us.

What is the thing you love most about your house pre-renovation? What do you think you will love most when the renovation is complete? 

We love our street & also the beautiful view from our back deck. I will love having more than 1 bathroom with teenage boys in the house!

Where have you drawn inspiration from for your renovation? How did you have to modify those thoughts to keep the project within budget and comply with the approval process?

We have drawn inspiration from other properties in the area and really thought about what we needed as a family, especially with our children getting older. The need for some separate living spaces especially…

We have tried to keep the project within budget by considering the use of different, more cost-efficient products in the tiling and flooring of the property. We also had a few ideas early on in the planning process that we have cut from the project. The approval process was actually quite easy given the fact we were very happy to keep the existing style of the house.

What is your key piece of advice to other homeowners thinking about renovating their homes? 

Be patient, do your research and try to find a good team that you can trust to listen to your needs and get the job done!

Thank you Georgina

Thank you very much Georgina for taking the time to bring us up to speed on your home renovation in Milton. We look forward to seeing more projects like this beautiful home renovation!

Tips & Tricks

Hydrostatic Valve vs Empty Pool

This little thing is a hydrostatic valve. It goes in the bottom of your pool to stop the pool from floating (or buckling) if the water level on the outside of the pool is higher than the level on the inside.

It doesn’t have a rated flow rate or a rated differential pressure.

But if it doesn’t work your pool might float out of the ground.

I used to think rainy days would fill a pool as quickly as the ground around a pool hence there wouldn’t be a need to worry.

But if you have bad site drainage and water runs towards your pool there is a very real chance your empty pool could float.

Whether you could claim for damage to your pool from ‘flood water’ depends on your insurer – but we all have access to aerial photos and we can tell if your pool has been empty for a long time.

Bottom line: take the hydrostatic valve out of the bottom of your pool when it is empty. Only put it back in when you intend to fill your pool up.

Tips & Tricks

Old Houses Move

This is Harry. G’day. I’m Harry. Harry lives in an old house. Yeah, it’s pretty old. Ever since it was built Harry’s house moved up and down with the seasons. My house is moving.

Back when Harry’s house was built, people understood that houses move and so they did some things to account for the effects of that movement.

“We paint our house every few years.”

“We have tongue and groove walls so I can’t tell there’s movement.”

“Our house has some hairline cracks but that’s okay, we know it’s not the Taj Mahal.”

They weren’t too concerned about a few cracks because they knew the house was built using strong materials that could accommodate some movement.

“My living room has asbestos cement walls. They’re very strong.”

“My builder uses fibro in the bathroom and tongue and groove in the living room. It’s just gorgeous.”

But eventually, the older house got sold to new owners.

“It’s time for me to move into a retirement village. See ya.”

And new owners moved in with new ideas.

“My wife wants to be able to watch the kids in the lounge room from the kitchen so we’re going to knock out this wall and put in a beam.”

“The house was looking pretty dated so we removed the asbestos cement walls and re-clad them with beautiful smooth plasterboard don’t you just love this color? “

And the old house kept on moving.

Now if anyone had asked Harry he would have said,

“This house always moved with the seasons. You better get used to it.”

But the new owners expected their house to perform like a new house.

“We can’t afford to repaint our house every couple of years.”

And the old house kept on moving.

One day, there was an almighty storm. The skies opened. Rain came bucketing down. Some houses even flooded.

“In Graceville Gaynor and Mike only bought their home three years ago I mean it’s our first home together you know it’s our yeah it’s you know it’s it’s our little sanctuary.”

After the storm things slowly started to return to normal.

People washed the mud out of their homes and dried out their belongings. Some homes were rebuilt. Some just removed their wall cladding to allow the walls to dry up.

Some houses seemed okay at the time but people got nervous.

“There are cracks in my walls. I’m worried my house is collapsing.”

“Ever since the flood, my house has moved. It must be because of the flood.”

“Please help! Our house is falling down.”

And the old house just kept on moving.

So what can be done about older houses that keep moving? Can they just be patched and painted after a storm or do they need to be strengthened in a way so that they never move again?

As a homeowner or a builder or an insurance company we have three options for you.

The movement in these older houses will continue each year – year after year – so option one is to tell the owners what to expect. Just because the walls are being clad in shiny new plasterboard doesn’t mean the house will suddenly stop moving.

The need for a patch and paint doesn’t go away when you buy an older house.

Owners need to be aware that cracks up to five millimeters wide are okay. They’re to be expected and the walls just need some love.

Older houses also need some maintenance like engaging a builder or a handyman to re-level the house every now and then with packers on top of the stumps or to replace some of the stumps with adjustable steel stumps so they can be leveled up or down a lot more easily.

Option Two is to try and remove some of the issues that we now know cause young and old houses to move each season.

  • Improve site drainage so that stormwater doesn’t sit beside or under a house for a long time.
  • Fix gutters and downpipes so they don’t overflow onto the ground beside the house.
  • Don’t plant potentially large trees right beside a house because we know that tree roots affect the performance of a house.
  • Fix broken and leaking stormwater and sewer pipes promptly.
  • Fix leaking taps and fill in dog holes so that water doesn’t sit near the footings.

Option Three is to upgrade the footing system to a more modern footing system to help protect the building from seasonal ground movement.

All of the existing stumps and footings need to be demolished and replaced with a grid of strong concrete beams under the house.

Option Three is effectively a major footing system upgrade.

This is very expensive and difficult to do and the work still doesn’t guarantee that the house won’t be affected by seasonal ground moisture changes and movement.

So the option you choose depends on your budget and the homeowner’s acceptance that older houses do move.

Some people just aren’t ready to accept that their house will move and crack each season so maybe they aren’t the best owners of an older home.

The danger with repairing an older home after a storm event is the home will continue to move and then the blame for that movement might be accidentally attributed to the builder that did the repairs.

That’s no fun for anybody.

So, what level of movement is okay in an older house and when should a homeowner actually start to worry.

  • A good rule of thumb is that a few cracks up to five millimeters wide are okay.
  • One or more cracks wider than five millimeters along with some sticking doors or windows means that you probably should get your house checked to see what you can do to improve the performance of the footings.
  • One or more cracks wider than 15 millimeters wide means that you probably need a structural engineer and a builder to check what is going on with your house – perhaps there is some termite damage or water damage in the building that needs to be repaired.

Unless something serious around your house changes like soil gets washed away or a slope subsides, most older houses will continue to stand up strong and proud with only some minor cracking each season.

So long as you’re a homeowner that can tolerate doing some maintenance around your house like getting cracks patched and painted or getting your stumps adjusted then an older house will continue to perform just fine for you.

If you’re less willing to accept cracking in your house then perhaps an older-style house isn’t the right kind of house for you.

I’m Matt Cornell from Cornell Engineers.

Tips & Tricks


Efflorescence. What is it? How does it affect your building? Is it bad and what do you need to do about it?

I’m Matt Cornell from Cornell Engineers. Let’s have a chat about efflorescence and what it means for your building.

Efflorescence is that salty substance that appears on walls and slabs and sometimes even ceilings -that is a sign of moisture coming through the surface.

By itself, it isn’t a structural defect but it’s a sign that something’s going on that needs further investigation and that your building needs some help.

So if we have a look at a couple of these photos, you can see that there’s blockwork, and salt coming through on the wall.

The wall itself is discolored in place – it’s a little bit darker around where the salt is located.

That’s part of the sign that you know that there’s moisture coming through.

So efflorescence is actually the salt that is left on the surface after moisture migrates through your cementitious or blockwork or brickwork surface.

The moisture dissolves salts out of the brickwork or blockwork or concrete and when the moisture comes to the surface the moisture evaporates leaving behind the salt crystals.

So it means there’s moisture coming through your surface and that means there’s moisture on the other side of the surface that needs to be handled, addressed and that problem solved.

Now again, efflorescence by itself is not a defect. It’s not a problem. It’s a sign of a problem.

It’s a sign, generally, of a moisture problem and that means you need to find that moisture and solve that problem.

When we look at what that looks like on paper in a wall, if we use a concrete measuring wall for example, and it might even be say a retaining wall where we know that there’s dirt on the other side of the wall when we’re standing on the inside and if there’s efflorescence on that surface then that’s a good sign that moisture is coming through the blockwork wall evaporating on the inside of the surface and leaving those salt crystals.

So you as the owner or the occupier or the person in charge of the maintenance for that building now you know that you need to go onto the other side of the wall find out where that moisture is coming from and solve that issue.

So we’ve already done quite a long video on solving drainage issues on houses on sloping sites and this ties in nicely to that in that moisture problem is going to be solved by doing some of those things in that video.

Once that solution has been attempted then it’s time to do some cleaning – take the efflorescence off the wall.

There are some quite good products that you can buy from hardware shops to dissolve efflorescence and take it off walls and surfaces and then wait to see if the efflorescence reappears – after you’ve solved the moisture issue. So, solve the moisture issue first.

Clean the efflorescence.

See if it comes back. If it comes back you’ve still got some more work to do – still got some moisture issues.

Now the other issues related to moisture coming into a building are the same things that we spoke about in the other video.

That steel reinforcement, for example, corrodes when it comes into contact with moisture.

The other things are leaks, the rot of timber, and mold.

So the moisture that’s coming through and causing leaving efflorescence could also be causing mold. And finally, uneven soil moisture conditions can cause house movement and damage and we cover that on our website.

So efflorescence. Not a problem itself but a sign that your building needs some help.

I’m Matt Cornell from Cornell Engineers.

Tips & Tricks

Don’t Engage a Structural Engineer if You are Selling Your Cracked House

You might be tempted to engage a structural engineer if you are selling your cracked house to write a report to explain that those cracks are only superficial cracks.

After all, the cracks have been there forever and you never worried about them.

You might just be wasting your money.!

Join Matt Cornell to find out why.


G’day. This is Matt Cornell from Cornell Engineers.

Today I’m answering one of the questions we get quite frequently and that is, “Do we, at Cornell Engineers, do inspections and provide reports for people who are selling their house?”

So, Tom, for example, was selling his house. He noticed cracks in the walls and thought that it might be a good idea to get an engineer’s report before he put his house on the market. His intention was to show the engineer’s report to prospective buyers and allay their fears.

Now while this sounds like a good idea in theory, what we have found is that most buyers do not trust the seller’s engineer’s report.

So, in fact, Tom if he were to engage us so that he could sell his house or to provide a report before he sells his house, is probably just wasting his time and his money.

Engineer checking plans on tablet


Because the first buyer that comes along or the buyer that comes along is more than likely going to read the report, not trust it, think that it’s been provided for the seller for the seller’s benefit, and then go out and get their own report.

The fact is engineers should be writing reports independently of who is paying them but that theory, or that feeling that people are worried that they can’t rely on the engineer’s report, that’s a real concern.

So our solution is, instead of Tom coming to us before he sells the house or as he’s preparing the house for sale, we recommend just about every time, that Tom and the buyer once he has a contract, engage the engineer together.

That way the buyer can attend the engineer’s inspection with the engineer. They can ask any questions that they feel like they would like answered They can have their name on the engineer’s report when it’s issued.

Even though Tom is maybe even paying fifty percent or a hundred percent of the report, it allays the buyer’s fears.

It becomes the buyer’s report or it helps the buyer feel more satisfied that the engineer has done a good job and is acting for both parties and it allows the buyer to ask the questions they want.

Building and Pest Report

Now don’t forget we also recommend that most buyers undertake a building and pest report.

On our website, we’ve talked about this.

Those building and pest reports, even for me, are a valuable resource and when I purchase properties, most times, we tend to get a building and pest inspection report as well.

So it’s that good. We definitely recommend using a building and pest inspector.

We have attended site inspections with the building and pest inspector – but more often than not it’s better value for money if the engineer attends to inspect a building after the building and pest inspector has been to answer any questions that remain.

Building and pest inspectors are required or tend to in any case, have a lot of recommendations to seek specialist advice, and a lot of that time, that tends to be structural engineering advice.

So we’d normally recommend that a building and pest inspection is done first and then if there are any structural issues that are raised in that report then you go out and you get your structural engineering report at that time.

This has been Matt Cornell from Cornell Engineers. I hope this has clarified our feeling or the best way we think you could spend your money on an engineer’s report if you are selling your cracked house.

If you’re buying or selling a house, we’re based in Brisbane. We’re working all across the state and at the moment, in fact, I’m coming back from Stradbroke Island, so we get around.

Give us a call if we can help you and we’ll see what we can do for you.

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Matt Cornell from Cornell Engineers.